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Vitamin C

Vitamin C, or ascorbic acid, is naturally produced in fruits and vegetables. The vitamin, which can be taken in dietary or supplementary form, is absorbed by the intestines.

That which the body cannot absorb is excreted in the urine. The body stores a small amount, but daily intake, preferably in dietary form, is recommended for optimum health.

Certain health conditions may cause vitamin C depletion, including diabetes and high blood pressure. People who smoke and women who take estrogen may also have lower vitamin C levels. In addition, men are more likely to be vitamin C depleted, as are the elderly. High stress levels have also been linked to vitamin C deficiency.

In addition, certain medical and surgical procedures may lower the levels of vitamin C in the body. It has been found that hemodialysis causes patients with kidney disease to lose as much as 66 mg per session. Similarly, patients who have had kidney transplants are at increased risk of vitamin C deficiency.


Severe vitamin C deficiency leads to scurvy, a disease common on ships prior to the eighteenth century, due to the lack of fresh fruits and other dietary vitamin C sources. Symptoms of scurvy include weakness, bleeding, tooth loss, bleeding gums, bruising, and joint pain.

Less serious vitamin C depletion can have more subtle effects such as weight loss, fatigue, weakened immune system (as demonstrated by repeated infections and colds), bruises that occur with minor syok and are slow to heal, and slow healing of other wounds.

Low vitamin C levels have also been associated with high blood pressure, increased heart attack risk, increased risk for developing cataracts, and a higher risk for certain types of cancer (i.e., prostate, stomach, colon, oral, and lung).

General use

Vitamin C is a critical component of both disease prevention and of basic body building processes. The therapeutic effects of vitamin C include:

• Allergy and asthma relief. Vitamin C is present in the lung’s airway surfaces, and insufficient vitamin C levels have been associated with bronchial constriction and reduced lung function. Some studies have associated vitamin C supplementation with asthmatic symptom relief, but results have been inconclusive and further studies are needed.
• Cancer prevention. Vitamin C is a known antioxidant and has been associated with reduced risk of stomach, lung, colon, oral, and prostate cancer.
• Cataract prevention. Long-term studies on vitamin C supplementation and cataract development have shown that supplementation significantly reduces the risk of cataracts, particularly among women. One study published in 2002 found that adequate vitamin C intake in women under 60 years of age reduced their risk of developing cataracts by 57%.
• Collagen production. Vitamin C assists the body in the manufacture of collagen, a protein that binds cells together and is the building block of connective tissues throughout the body. Collagen is critical to the formation and ongoing health of the skin, cartilage, ligaments, corneas, and other bodily tissues and structures. Vitamin C is also thought to promote faster healing of wounds and injuries because of its role in collagen production.
• Diabetes control. Vitamin C supplementation may assist diabetics in controlling blood sugar levels and improving metabolism.
• Gallbladder disease prevention. A study of over 13,000 subjects published in the Archives in Internal Medicine found that women who took daily vitamin C supplements were 34% less likely to contract gallbladder disease and gallstones, and that women deficient in ascorbic acid had an increased prevalence of gallbladder disease.
• Immune system booster. Vitamin C increases white blood cell production and is important to immune system balance. Studies have related low vitamin C levels to increased risk for infection. Vitamin C is frequently prescribed for HIV-positive individuals to protect their immune system.
• Neurotransmitter and hormone building. Vitamin C is critical to the conversion of certain substances into neurotransmitters, brain chemicals that facilitate the transmission of nerve impulses across a synapse (the space between neurons, or nerve cells).

Such neurotransmitters as serotonin, dopamine, and norepinephrine are responsible for the proper functioning of the central nervous system, and a deficiency of neurotransmitters can result in psychiatric illness. Vitamin C also helps the body manufacture adrenal hormones.

Other benefits of vitamin C are less clear cut and have been called into question with conflicting study results. These include vitamin C’s role in treating the common cold, preventing heart disease, and treating cancer.

Respiratory health

Doses of vitamin C may reduce the duration and severity of cold symptoms, particularly in people who are vitamin C deficient.

The effectiveness of vitamin C therapy on colds seems to be related to the person’s dietary vitamin C intake and their general health and lifestyle. In addition, however, other researchers have found that vitamin C is associated with improved lung function and overall respiratory health.

Heart disease prevention

Some studies have indicated that vitamin C may prevent heart disease by lowering total blood cholesterol and LDL cholesterol and raising HDL, or good cholesterol, levels.

The antioxidant properties of vitamin C have also been associated with protection of the arterial lining in patients with coronary artery disease. A study published in 2002 reported that the protective effects of vitamin C on the lining of the arteries reduces the risk of heart disease in patients who have received heart transplants.

On the other hand, the results of a recent study conducted at the University of Southern California and released in early 2000 have cast doubt on the heart protective benefits of vitamin C. The study found that daily doses of 500 mg of vitamin C resulted in a thickening of the arteries in study subjects at a rate 2.5 times faster than normal.

Thicker arterial walls can cause narrow blood vessels and actually increase the risk for heart disease. Study researchers have postulated that the collagen-producing effects of vitamin C could be the cause behind the arterial thickening.

Further studies will be needed to determine the actual risks and benefits of vitamin C in relation to heart disease and to establish what a beneficial dosage might be, if one exists. For the time being, it is wise for most individuals, particularly those with a history of heart disease, to avoid megadoses over 200 mg because of the risk of arterial thickening.

Source of vitamin C

Blood pressure control

A 1999 study found that daily doses of 500 mg of vitamin C reduced blood pressure in a group of 39 hypertensive individuals. Scientists have hypothesized that vitamin C may improve high blood pressure by aiding the function of nitric oxide, a gas produced by the body that allows blood vessels to dilate and facilitates blood flow.

Again, recent findings that vitamin C may promote arterial wall thickening seem to contradict these findings, and further long-term studies are needed to assess the full benefits and risks of vitamin C in relation to blood pressure control.

Cancer treatment

Researchers disagree on the therapeutic use of vitamin C in cancer treatment. On one hand, studies have shown that tumors and cancer cells absorb vitamin C at a faster rate than normal cells because they have lost the ability to transport the vitamin.

In addition, radiation and chemotherapy work in part by stimulating oxidation and the growth of free radicals in order to stop cancer cell growth. Because vitamin C is an antioxidant, which absorbs free radicals and counteracts the oxidation process, some scientists believe it could be counterproductive to cancer treatments.

The exact impact vitamin C has on patients undergoing chemotherapy and other cancer treatments is not fully understood, and for this reason many scientists believe that vitamin C should be avoided by patients undergoing cancer treatment.

On the other side of the debate are researchers who believe that high doses of vitamin C can protect normal cells and inhibit the growth of cancerous ones. In lab-based, in vitro studies, cancer cells were killed and/or stopped growing when large doses of vitamin C were administered.

Researchers postulate that unlike normal healthy cells, which will take what they need of a vitamin and then discard the rest, cancer cells continue to absorb antioxidant vitamins at excessive rates until the cell structure is effected, the cell is killed, or cell growth simply stops. However, it is important to note that there have been no in vivo controlled clinical studies to prove this theory.

Based on the currently available controlled clinical data, cancer patients should avoid taking vitamin C supplementation beyond their recommended daily allowance.

Preparations

The U.S. recommended dietary allowance (RDA) of vitamin C was changed in 2000 to reflect growing recognition of the importance of vitamin C in the diet as an antioxidant as well as a protection against deficiency.

The new values are as follows:

• men: 90 mg
• women: 75 mg
• pregnant women: 80 mg
• lactating women: 95 mg
• smokers: should consume an additional 35 mg

The National Academy of Sciences also established for the first time an upper limit (UL), or maximum daily dose, of 2,000 mg. Daily values for the vitamin as recommended by the U.S. Food and Drug Administration, the values listed on food and beverage labeling, remain at 60 mg for both men and women age four and older.

Many fruits and vegetables, including citrus fruits and berries, are rich in vitamin C. Foods rich in vitamin C include raw red peppers (174 mg/cup), guava (165 mg/fruit), orange juice (124 mg/cup), and black currants (202 mg/cup).

Rose hips, broccoli, tomatoes, strawberries, papaya, lemons, kiwis, and people. Fresh, raw fruits and vegetables contain the highest levels of the vitamin.

Both heat and light can reduce vitamin C potency in fresh foods, so overcooking and improper storage should be avoided. Sliced and chopped foods have more of their surface exposed to light, so keeping vegetables and fruits whole may also help to maintain full vitamin potency.

Vitamin C Infographic

Vitamin C supplements are another common source of the vitamin. Individuals at risk for vitamin C depletion such as smokers, women who take birth control pills, and those with unhealthy dietary habits may benefit from a daily supplement. Supplements are available in a variety of different forms including pills, capsules, powders, and liquids. Vitamin C formulas also vary.

Common compounds include ascorbic acid, calcium ascorbate, sodium ascorbate, and C complex. The C complex compound contains a substance called bioflavonoids, which may enhance the benefits of vitamin C. Vitamin C is also available commercially as one ingredient of a multivitamin formula.

The recommended daily dosage of vitamin C varies by individual need, but an average daily dose might be 200 mg. Some healthcare providers recommend megadoses (up to 40 g) of vitamin C to combat infections.

However, the efficacy of these megadoses has not been proven, and in fact, some studies have shown that doses above 200 mg are not absorbed by the body and are instead excreted.

Precautions

Overdoses of vitamin C can cause nausea, diarrhea, stomach cramps, skin rashes, and excessive urination.

Because of an increased risk of kidney damage, persons with a history of kidney disease or kidney stones should never take dosages above 200 mg daily, and should consult with their healthcare provider before starting vitamin C supplementation.

A 1998 study linked overdoses (above 500 mg) of vitamin C to cell and DNA damage. However, other studies have contradicted these findings, and further research is needed to establish whether high doses of vitamin C can cause cell damage.

Side effects

Vitamin C can cause diarrhea and nausea. In some cases, side effects may be decreased or eliminated by adjusting the dosage of vitamin C.

Interactions

Vitamin C increases iron absorption, and is frequently prescribed with or added to commercial iron supplements for this reason.

Individuals taking anticoagulant, or blood thinning, medications should speak with their doctor before taking vitamin C supplements, as large doses of vitamin C may impact their efficacy.

Large amounts of vitamin C may increase estrogen levels in women taking hormone supplements or birth control medications, especially if both the supplement and the medication are taken simultaneously. Women should speak with their doctor before taking vitamin C if they are taking estrogen-containing medications.

Estrogen actually decreases absorption of vitamin C, so larger doses of vitamin C may be necessary. A healthcare provider can recommend proper dosages and the correct administration of medication and supplement.

Persons who take aspirin, antibiotics, and/or steroids should consult with their healthcare provider about adequate dosages of vitamin C. These medications can increase the need for higher vitamin C doses.

Large dosages of vitamin C can cause a false-positive result in tests for diabetes.

Vitamin B Complex

The vitamin B complex consists of 12 related water-soluble substances. Eight are considered essential vitamins because they need to be included in the diet. Four are not essential because the body can synthesize them.

Although these vitamins are chemically distinct, they are grouped together because they are found with one another in the same foods. Since they are water-soluble, most are not stored for any length of time, and must be replenished daily.

The eight vitamins have both names and corresponding numbers. They are:

• B1 (thiamin)
• B2 (riboflavin)
• B3 (niacin)
• B5 (pantothenic acid)
• B6 (pyridoxine)
• B7 (biotin)
• B9 (folic acid)
• B12 (cobalamin)

Biotin is not always included among B complex supplements. The numbers that appear to have been skipped were found to be duplicate substances or non-vitamins. The four unnumbered components of the B complex that can be synthesized by the body are choline, inositol, PABA, and lipoic acid.

As a group, the B vitamins have a broad range of functions, including the maintenance of myelin, which is the covering of nerve cells. A breakdown of myelin can cause a large and devastating variety of neurologic symptoms.

B vitamins are also key to producing energy from nutrients that are consumed. Three members of this group—folic acid, pyridoxine, and cobalamin—work together to keep homocysteine levels low. This is quite important, since high homocysteine levels are associated with heart disease.

Some B vitamins prevent certain birth defects (including cleft palate and neural tube defects), maintain healthy red blood cells, support immune function, regulate cell growth, aid in hormone production, and may have a role in preventing certain types of cancer. They also help maintain healthy skin, hair, and nails.

General use

There are many claims regarding the usefulness of various B vitamins. Thiamine is thought to be supportive for people with Alzheimer’s disease, a disorder that is also associated with low levels of pyridoxine and cobalamin. High doses of niacin lower cholesterol, and balance high-density (HDL) and low-density (LDL) lipoproteins.

This should be done under medical supervision only. Some evidence shows that niacin may prevent juvenile diabetes (type 1, insulin dependent) in at-risk children. It may maintain pancreatic excretion of some insulin for a longer time than would occur normally.

What else do B vitamins do?

Niacin has also been used to relieve intermittent claudication and osteoarthritis,although the dose for the latter may lead to liver problems. The frequency of migraines may be significantly reduced, and the severity decreased, by the use of supplemental riboflavin.

Pyridoxine is used therapeutically to lower the risk of heart disease, to relieve nausea associated with morning sickness, and to treat premenstrual syndrome (PMS). In conjunction with magnesium, pyridoxine may have some beneficial effects on the behavior of children with autism.

Cobalamin supplementation has been shown to improve male fertility. Depression, dementia, and mental impairment are often associated with deficiencies of both cobalamin and folic acid. Folic acid may reduce the odds of cervical or colon cancer in certain risk groups.

Deficiency

Vitamin B complex is most often used to treat deficiencies that are caused by poor vitamin intake, difficulties with vitamin absorption, or conditions causing increased metabolism, such as hyperthyroidism, which deplete vitamin levels at a higher than normal rate.

Biotin and pantothenic acid are rarely deficient since they are broadly available in foods, but often persons lacking one type of B vitamin are lacking other B components as well. An individual who may have symptoms due to an inadequate level of one vitamin may suffer from an undetected underlying deficiency as well.

One possibility of particular concern is that taking folic acid supplements can cover up the symptoms of cobalamin deficiency. This scenario could result in permanent neurologic damage if the cobalamin shortage remains untreated.

Some of the B vitamins have unique functions within the body that allow a particular deficiency to be readily identified. Often, however, they work in concert so symptoms due to various inadequate components may overlap.

Vitamin B Complex Infographic

In general, poor B vitamin levels will cause profound fatigue and an assortment of neurologic manifestations, which may include weakness, poor balance, confusion, irritability, memory loss, nervousness, tingling of the limbs, and loss of coordination.

Depression may be an early sign of significantly low levels of pyridoxine, as well as other B vitamins. Additional symptoms of vitamin B deficiency are sleep disturbances, nausea, poor appetite, frequent infections, and skin lesions.

A certain type of anemia (megaloblastic) is an effect of inadequate cobalamin. This anemia can also occur if a person stops secreting enough intrinsic factor in the stomach.

Intrinsic factor is essential for the absorption of cobalamin. A lack of intrinsic factor also leads to pernicious anemia, so called because it persists despite iron supplementation. Neurologic symptoms often precede anemia when cobalamin is deficient.

A severe and prolonged lack of niacin causes a condition called pellagra. The classic signs of pellagra are dermatitis, dementia, and diarrhea. It is very rare now, except in alcoholics, strict vegans, and people in areas of the world with very poor nutrition.

Thiamine deficiency is similarly rare, except among the severely malnourished and alcoholics. A significant depletion causes a condition known as beriberi, which can cause weakness, leg spasms, poor appetite, and loss of coordination.

Wernicke-Korsakoff syndrome is the most severe form of deficiency, and occurs in conjunction with alcoholism. Early stages of neurologic symptoms are reversible, but psychosis and death may occur if the course is not reversed.

Risk factors for deficiency

People are at higher risk for deficiency if they have poor nutritional sources of B vitamins, take medications, or have conditions that impair absorption, or are affected by circumstances causing them to require above-normal levels of vitamin B components. Since the B vitamins often work in harmony, a deficiency in one type may have broad implications.

Poor intake of B vitamins is most often a duduk perkara in strict vegetarians and the elderly. People who frequently fast or diet may also benefit from B vitamin supplements. Vegans need to use brewer’s yeast or other sources of supplemental cobalamin, since the only natural sources are meats.

Risk factors that may decrease absorption of some B vitamins include smoking; excessive use of alcohol; surgical removal of portions of the digestive tract; and advanced age. Absorption is also impaired by some medications.

Some of the drugs that may cause decreased absorption are corticosteroids, colchicine, metformin, phenformin, omeprazol, colestipol, cholestyramine, methotrexate, 5-fluorouracil, tricyclic antidepressants, and slow-release potassium.

A person’s requirement for vitamin B complex may be increased by such conditions as pregnancy, breastfeeding, emotional stress, and physical stress due to surgery or injury. People who are very physically active require extra riboflavin. Use of birth control pills also increases the need for certain B vitamins.

Recent research indicates that children with sickle cell anemia are at high risk for elevated homocysteine levels and pyridoxine deficiency.

Studies of folic acid deficiency caused by cancer chemotherapy indicate that some patients are at greater risk than others due to genetic variations in metabolism of the B vitamins. Further research is needed to determine the role of these genetic factors in vitamin deficiency states.

Preparations

Natural sources

Although they are prevalent in many foods, fresh meats and dairy products are the best sources for most of the B vitamins. Cobalamin is only found naturally in animal source foods.

Freezing of food and exposing foods or supplements to light may destroy some of the vitamin content. Dark-green leafy vegetables are an excellent source of folic acid. To make the most of the B vitamins contained in foods, they should not be overcooked. It is best to steam vegetables, rather than boil or simmer them.

Supplemental sources

B vitamins are generally best taken in balanced complement, unless there is a specific deficiency or need for an individual vitamin. An excess of one component may lead to depletion of the others.

Injectable and oral forms of supplements are available. The injectable types may be more useful for those with deficiencies due to problems with absorption. B complex products vary in terms of components and dose level contained within them.

Individual components are also available as supplements. These are best used with the advice of a health care professional. Some are valuable when addressing specific problems such as pernicious anemia. Strict vegetarians will need to incorporate a supplemental source of B₁₂ in their diets.

Precautions

In many cases, large doses of water-soluble vitamins can be taken with no ill effects since excessive amounts are readily excreted. However, liver inflammation may occur when niacin is taken at daily doses of over 500 mg. This duduk perkara occurs more often at doses six times as high.

It is generally reversible once the supplementation is stopped. Niacin may also cause difficulty in controlling blood sugar in diabetics. It can increase uric acid levels, which will aggravate gout. Those with ulcers could be adversely affected, as niacin increases the production of stomach acid.

Niacin also lowers blood pressure due to its vasodilatory effect, so it should not be taken in conjunction with medications that treat high blood pressure. If a form of niacin known as inositol hexaniacinate is taken, the beneficial effects on cholesterol are maintained without incurring the problems of flushing, gout, and ulcers.

High doses of pyridoxine may cause liver inflammation or permanent nerve damage. Megadoses of this vitamin are not necessary or advisable.

Thoseon medications for seizures, high blood pressure, and Parkinson’s disease are at increased risk for interactions. Persons who have chronic health conditions, or take other medications, should seek the advice of a health professional before beginning any jadwal of supplementation.

Side effects

In large amounts, niacin commonly causes flushing and headache, although this can be avoided by taking it in the form of inositol hexaniacinate. Large doses of riboflavin result in very bright yellow urine.

Interactions

Some medications may be affected by B vitamin supplementation, including those prescribed for high blood pressure; Parkinson’s disease (such as levodopa, which is inactivated by pantothenic acid); and epileptiform conditions.

Folic acid interacts with Dilantin (a brand name for phenytoin sodium), as well as other anticonvulsants. Large amounts of vitamin C taken within an hour of vitamin B supplements will destroy the cobalamin component. Niacin may interfere with control of blood sugar in people on antidiabetic drugs.

Isoniazid, a medication to treat tuberculosis, can impair the proper production and utilization of niacin. Antibiotics potentially decrease the level of some B vitamins by killing the digestive tract bacteria that produce them.

Cobalamin, also known as B₁₂, is a member of the water-soluble family of B vitamins. It is a key factor in the body’s proper use of iron and formation of red blood cells.

The nervous system also relies on an adequate supply of cobalamin to function appropriately, as it is an essential component in the creation and maintenance of the myelin sheath that lines nerve cells.

Other roles of cobalamin include working with pyridoxine (vitamin B₆ and folic acid to reduce harmful homocysteine levels, participating in the metabolization of food, and keeping the immune system operating smoothly.

General use

Very small amounts of cobalamin are needed to maintain good health. The RDA value is 0.3 micrograms (mcg) for infants under 6 months, 0.5 mcg for those 6 months to 1 year old, 0.7 mcg for children 1-3 years old, 1.0 mcg for children 4-6 years old, 1.4 mcg for children 7-10 years old, and 2 mcg for those 11 years of age and older. Requirements are slightly higher for pregnant (2.2 mcg) and lactating (2.6 mcg) women.


The primary conditions that benefit from supplementation with cobalamin are megaloblastic and pernicious anemia. Megaloblastic anemia is a state resulting from an inadequate intake of cobalamin, to which vegans are particularly susceptible because of the lack of animal food sources. Vegans, who do not consume any animal products including meat, dairy, or eggs, should take at least 2 mcg of cobalamin per day in order to prevent this condition.

In the case of pernicious anemia, intake may be appropriate but absorption is poor due to a lack of normal stomach substance, called intrinsic factor, that facilitates absorption of vitamin B₁₂. Large doses are required to treat pernicious anemia, which occurs most commonly in the elderly population as a result of decreased production of intrinsic factor by the stomach.

Supplements are generally effective when taken orally in very large amounts (300-1000 mcg/day) even if no intrinsic factor is produced. These supplements require a prescription, and should be administered with the guidance of a health care provider. Injections, instead of the supplements, are often used.

Those who have infections, burns, some types of cancer, recent surgery, illnesses that cause decay or loss of strength, or high amounts of stress may need more than the RDA amount of B₁₂ and other B vitamins. A balanced supplement is the best approach.

Male infertility can sometimes be resolved through use of cobalamin supplements. Other conditions that may be improved by cobalamin supplementation include: asthma, atherosclerosis (hardening of the arteries caused by plaque formation in the arteries), bursitis (inflammation of a bodily pouch, especially the shoulder or elbow), Crohn’s disease (chronic recurrent inflammation of the intestines), depression, diabetes, high cholesterol, osteoporosis, and vitiligo (milky-white patches on the skin). There is not enough evidence to judge whether supplementation for these diseases is effective.

Preparations

Vitamin B12 foods

Natural sources

Usable cobalamin is only found naturally in animal source foods. Fresh food is best, as freezing and exposure to light may destroy some of the vitamin content.

Clams and beef liver have very high cobalamin levels. Other good sources include chicken liver, beef, lamb, tuna, flounder, liverwurst, eggs, and dairy products. Some plant foods may contain cobalamin, but it is not in a form that is usable by the body.

Supplemental sources

Cobalamin supplements are available in both oral and injectable formulations. A nasal gel is also made. Generally a balanced B-complex vitamin is preferable to taking high doses of cobalamin unless there is a specific indication for it, such as megaloblastic anemia. Strict vegetarians will need to incorporate a supplemental source of B₁₂ in the diet.

Cyanocobalamin is the form most commonly available in supplements. Two other, possibly more effective, types are hydrocobalamin and methyl-cobalamin. As with all supplements, cobalamin should be stored in a cool, dry, dark place and out of the reach of children.

Deficiency

Cobalamin deficiency may be manifested as a variety of symptoms since cobalamin is so widely used in the body. Severe fatigue may occur initially.

Effects on the nervous system can be wide-ranging, and include weakness, numbness and tingling of the limbs, memory loss, confusion, delusion, poor balance and reflexes, hearing difficulties, and even dementia. Severe deficiency may appear similar to multiple sclerosis.

Nausea and diarrhea are possible gastrointestinal signs. The anemia that results from prolonged deficiency may also be seen as a pallor, especially in mucous membranes such as the gums and the lining of the inner surface of the eye.

Vitamin B12 Deficiency.

Megaloblastic anemia is a common result of inadequate cobalamin. This condition can also result if a person stops secreting enough intrinsic factor in the stomach, a substance essential for the absorption of cobalamin.

In adequate intrinsic factor leads to pernicious anemia, so called because it persists despite iron supplementation. Long-term deficiencies of cobalamin also allow homocysteine levels to build up. Negative effects of large amounts of circulating homocysteine include heart disease, and possibly brain toxicity.

Taking high levels of folic acid supplements can mask cobalamin deficiency and prevent the development of megaloblastic anemia, but neurological damage can still occur. This damage may become permanent if the cobalamin deficiency persists for a long period of time.

Risk factors for deficiency

The primary groups at risk for cobalamin deficiency are vegans who are not taking supplements, and the elderly. Older adults are more likely to have both insufficient intrinsic factor secreted by the stomach and low levels of stomach acid, causing cobalamin to be poorly absorbed. Malabsorptive diseases and stomach surgery can also predispose to a deficiency.

Precautions

People who are sensitive to cobalamin or cobalt should not take cobalamin supplements. Symptoms of hypersensitivity may include swelling, itching, and shock.

Adverse effects resulting from B₁₂ supplementation are rare. Cobalamin should also be avoided by those who have a type of hereditary optic nerve atrophy known as Leber’s disease.

Side effects

Very high doses of cobalamin may sometimes cause acne.

Interactions

The Power of B12

Large amounts of vitamin C taken within an hour of vitamin B supplements will destroy the cobalamin component. Absorption of cobalamin is also impaired by deficiencies of folic acid, iron, or vitamin E. Improved absorption occurs when it is taken with other B vitamins or calcium. Some medications may also cause an increased use or decreased absorption of this vitamin.

Those on colchicine, corticosteroids, methotrexate, metformin, phenformin, oral contraceptives, cholestyramine, colestipol, clofibrate, epoetin, neomycin, or supplemental potassium may need extra cobalamin. Use of nicotine products or excessive alcohol can deplete B₁₂.

Vitamin A

Vitamin A is one of four fat-soluble vitamins necessary for good health. It serves an important role as an antioxidant by helping to prevent free radicals from causing cellular damage.

Adequate levels are important for good eyesight, and poor night vision may be one of the first symptoms of a deficiency. It is also necessary for proper function of the immune, skeletal, respiratory, reproductive, and integumentary (skin) systems.

General use

An adequate level of vitamin A unquestionably contributes to good health. It is essential for the proper function of the retina, where it can act to prevent night blindness, as well as lower the odds of getting age-related macular degeneration (AMD), which is the most common cause of blindness in the elderly.

There is also evidence that good levels of vitamin A in the form of carotenoids may decrease the risk of certain cancers, heart attacks, and strokes. The immune system is also strengthened.


It is unclear, however, if supplemental forms of vitamin A have the same benefit as consuming the nutrient in natural foods in the case of a person without deficiency. Taking high levels of vitamin A in any supplemental form is not advisable without the counsel of a healthcare professional.

Preparations

Natural sources

There are two basic forms of vitamin A. Retinoids, the active types, are contained in animal sources, including meat, whole milk, and eggs. Liver is particularly rich in vitamin A, since it is one of the storage sites for excess.

Precursor forms of the vitamin (carotenoids) are found in orange and leafy green produce such as sweet potatoes, carrots, collard greens, spinach, winter squash, kale, and turnip greens. Very fresh foods have the highest levels, followed by frozen foods. Typically, canned produce has little vitamin A.

Preparing vegetables by steaming, baking, or grilling helps them to release the carotenes they contain. Alpha and beta carotene, as well as some of the other lesser-known carotenoids, can be converted to vitamin A in the small intestine. This is done by the body on an as-needed basis, so there is no risk of overdose as there is with the active form.

Supplemental sources

Supplements may contain either the active or precursor forms of vitamin A. The active form may be more desirable for those who may have some difficulty in converting the carotenoids into the active vitamin. This is more often true in those over age 55 or who have a condition that impairs the absorption of fat.

There is a water-soluble form of the vitamin, retinyl palmitate, which may be better utilized in the latter case. Carotenes are also available either as oil-based or natural water-based formulas. Be sure to store both away from light and heat, which will destroy them.

Units

There are several units that can express the amount of vitamin A activity in a product. Many supplements are still labeled with the old International Unit (IU), although the more current and most accurate unit is the Retinol Equivalent (RE). The new measurement distinguishes between the differences in absorption of retinol and beta carotene. One RE is equal to one microgram (MICROg) of retinol, or six MICROg of beta carotene.

Dose limits

Adults should take no more than 25,000 IU (5,000 RE) per day of vitamin A in its active form, except in the case of women who are pregnant or may become pregnant. The latter group should not exceed 10,000 IU (2,000 RE) per day in order to avoid potential toxic effects to the fetus.

The best way to get vitamins is in the natural food form, as the complexities are not always either known or reproducible in a supplement. A diet rich in foods containing carotenoids is optimal, but in the event of nutritional deficiencies, supplements may be needed.

Mixed carotenoids are preferable to either large doses of vitamin A or pure beta carotene supplements to avoid toxicity and maximize healthful benefits. Some of the minor carotenoids appear to have beneficial effects that are still being explored.

A good mixture will contain alpha and beta carotene, as well as lycopene and xanthophylls. Eating foods high in many carotenoids may confer some benefits—such as a lower risk of cancer, heart attacks, and strokes—which a supplement may not.

Deficiency

Levels of vitamin A low enough to cause symptomatic deficiency are uncommon in people of normal health in industrialized nations.

Symptoms of deficiency may include, but are not limited to, loss of appetite, poor immune function causing frequent infections (especially respiratory), hair loss, rashes, dry skin and eyes, visual difficulties including night blindness, poor growth, and fatigue. Generally symptoms are not manifested unless the deficiency has existed for a period of months.

Deficiencies are more likely in people who are malnourished, including alcoholics, the chronically ill, and those with impaired fat absorption. Another group at increased risk of vitamin A deficiency are persons with type 1 diabetes whose disorder is poorly controlled. People with normal health and nutritional status have a considerable vitamin A reserve.

In countries where nutritional status tends to be poor and deficiency is more common, vitamin A has been found to reduce the mortality rate of children suffering from a number of different viral infections.

Experts in plant genetics have been working on a strain of rice that contains beta carotene, hoping to help people in developing countries avoid the risk of vitamin A deficiency. Known as Golden Rice, the new strain is being sent to research institutes in developing countries for further study.

Risk factors for deficiency

Taking the RDA level of a nutrient will prevent a deficiency in most people, but under certain circumstances, an individual may require higher doses of vitamin A.

Those who consume alcoholic beverages may be more prone to vitamin A deficiency. People taking some medications, including birth control pills, methotrexate, cholestyramine, colestipol, and drugs that act to sequester bile will also need larger amounts.

Those who are malnourished, chronically ill, or recovering from surgery or other injuries may also benefit from a higher than average dose. Patients undergoing treatments for cancer, including radiation and chemotherapy, typically have compromised immune systems that may be boosted by judicious supplementation with vitamin A.

Other conditions that may impair vitamin A balance include chronic diarrhea, cystic fibrosis, and kidney or liver disease. Diabetics are often deficient in vitamin A, but may also be more susceptible to toxicity. Any supplementation for these conditions should be discussed with a healthcare provider.

Supplements are best taken in the form of carotenoids to avoid any potential for toxicity. There is not an established RDA for beta carotene. Recommendations for how much to take vary between 6 and 30 mg a day, but the middle range—around 15 mg—is a reasonable average.

Precautions

Overdose can occur when taking megadoses of the active form of this vitamin. Amounts above what is being utilized by the body accumulate in the liver and fatty tissues.

Symptoms may include dry lips and skin, bone and joint pain, liver and spleen enlargement, diarrhea, vomiting, headaches, blurry or double vision, confusion, irritability, fatigue, and bulging fontanel (soft spot on the head) in infants; these are most often reversible, but a doctor should be contacted if a known overdose occurs. Very high levels of vitamin A may also create deficiencies of vitamins C, E, and K.

Symptoms will generally appear within six hours following an acute overdose, and take a few weeks to resolve after ceasing the supplement. Children are more sensitive to high levels of vitamin A than adults are, so instructions on products designed for children should be followed with particular care. Vitamin supplements should always be kept out of reach of children.

It is especially important to avoid overdoses in pregnancy, as it may cause miscarriage or fetal malformations. Using supplements that provide carotenoids will avoid the potential of overdose.

Those with kidney disease are also at higher risk for toxicity due to either vitamin A or beta carotene, and should not take these supplements without professional healthcare advice.

There is some evidence that taking beta carotene supplements puts smokers at a higher risk of lung cancers. The CARET (Beta Carotene and Retinol Efficacy Trial) study is one that demonstrated this effect. Clarification through more study is needed, as evidence also exists showing that beta carotene, along with other antioxidants, can be a factor in cancer prevention.

For example, a team of American researchers has recently reviewed evidence that vitamin A protects against bladder cancer, and a group in Germany is testing an aerosol form of vitamin A to prevent lung cancer.

Some of the lesser known carotenoids may be key factors in the relationship between vitamin intake and cancer. Whole sources of vitamin A are better obtained from foods than from supplements. Smokers should consult with a healthcare provider before taking supplemental beta carotene.

Side effects

Very high levels of carotenoids (carotenemia) may cause an orange discoloration of the skin, which is harmless and transient.

Interactions

Vitamin A supplements should not be taken in conjunction with any retinoid medications, including isotretinoin (Accutane), a drug used to treat acne. There is a higher risk of toxicity.

A very low fat diet or use of fat substitutes impairs absorption of all the fat-soluble vitamins, including A. Mineral oil and aluminum-containing antacids may also inhibit absorption, as do the cholesterol-lowering drugs cholestyramine and colestipol.

Vitamin A reserves of the body are depleted by a number of substances, including alcohol, barbiturates, caffeine, cortisone, tobacco, and very high levels of vitamin E. Overuse of alcohol and vitamin A together may increase the possibility of liver damage.

Taking appropriate doses of vitamin C, vitamin E, zinc, and selenium optimizes absorption and use of vitamin A and carotenoids. As vitamin A is fat-soluble, a small amount of dietary fat is also helpful.

Studies of both children and pregnant women with iron deficiency anemia show that this condition is better treated with a combination of iron supplements and vitamin A than with iron alone.

Bee sting

Venom immunotherapy is the process of injecting venom to treat various conditions. The most common form of venom immunization is bee venom therapy (BVT), with honeybee venom or stingers used to treat conditions.

BVT is one form of apitherapy, which is the therapeutic use of products made by honeybees. Other products used in apitherapy include bee pollen and royal jelly.

Origins

Apitherapy is thousands of years old. In ancient Egypt, venom from bee stings was used to treat arthritis. Hippocrates, the Greek physician known as the “father of medicine,” used bee stings for treatments several centuries before the birth of Christ. Descriptions of apitherapy are found in 2,000-year-old Chinese writings, the Bible, and the Koran.


Bee venom therapy has remained part of folk medicine throughout the centuries. The modern study of apitherapy is said to have started in 1888, with Austrian physician Phillip Terc’s research titled “Report about a Peculiar Connection between the Beestings and Rheumatism.”

Benefits

Although a bee sting is painful for most people, the sting can be fatal to some. Approximately 15% of the population is allergic to the sting of such insects as bees and wasps. Allergic reactions range from mild to life-threatening.

In mainstream allopathic medicine, honeybee venom is used to treat people who are allergic to bee stings. A small amount of venom is injected during desensitization treatments to help patients develop a tolerance to stings.

Honeybee venom immunotherapy is used to treat many other conditions in alternative medicine. BVT is regarded as an effective treatment for arthritis, asthma.

Bee venom is also said to relieve premenstrual syndrome (PMS) and conditions related to menopause. However, BVT is most commonly used as an anti-inflammatory remedy for arthritis and MS. Advocates maintain that it will provide relief for rheumatoid arthritis when injected into the joints.

Bee venom is also used to lessen the pain and swelling of osteoarthritis as well as such inflammations and injuries as tendinitis and bursitis. Furthermore, people diagnosed with MS say that BVT significantly reduces symptoms that include muscle spasms and tiredness.

Description

Bee venom therapy involves the injection of venom by a needle, insertion of the stinger, or stinging by live bees. While a licensed physician must give injections, other treatments can be done by a bee venom therapist, a beekeeper, the patient, or a friend or relative.

The cost and length of treatment depends on the condition, as well as when and where a person is treated. If a physician provides the treatment, the doctor’s appointment may be covered by health insurance. Rates for other therapies are set by beekeepers and bee venom therapists. Information about these providers can be found through organizations such as the American Apitherapy Society.

The society’s resources include an extensive web site with information about BVT. Apitherapy resources include books and videos about home treatment. Live bees can be ordered by mail; one business in June 2000 charged $50 for four boxes, each containing about 60 bees.

When live bees are utilized, tweezers are used to remove one bee from a container such as a box, jar, or hive. The bee is held over the area to be treated until it stings the patient. The stinger is removed after three to five minutes.

Patients receive an average of two to five stings per session. The number of stings and the number of sessions varies with the condition treated. Tendinitis might require two to three stings per session for two to five sessions. Arthritis is sometimes treated with several stings per session at two to three weekly sessions.

MS may take months to treat. While BVT advocates say MS patients are more energetic after several sessions, they maintain that treatment should be done two to three times weekly for six months.

Preparations

Before beginning venom immunotherapy, a person should be tested for allergies. If a relative or friend plans to help with the therapy, that person should be tested too. Bee venom may cause a severe allergic reaction called anaphylaxis.

The symptoms of anaphylaxis include shock, respiratory distress, and in some cases, death. Even if tests indicate that a person isn’t allergic to bee stings, it is important to obtain an emergency bee-sting allergy kit before beginning treatment.

Precautions

People should check with their doctor or practitioner before beginning bee venom immunotherapy. The therapy is not recommended for pregnant women, diabetics, people with heart conditions, tuberculosis, or infections.

An allergy test is a must before starting bee venom therapy. A person who is allergic to bee stings should not start venom treatment. In some cases, scarring and infections have resulted when the stinger was left in too long.

Side effects

If there is an allergic reaction to bee venom therapy, emergency treatment should be started. Such symptoms as minor itching and swelling, however, are not causes for alarm. They are signs of the healing process.

Research and general acceptance

During the late 1990s, researchers in countries including the United States, France, and Russia began researching the effect of bee venom immunotherapy on humans. Before that, research with such animals as mice indicated that venom could be beneficial for treating inflammatory conditions.

Anecdotal reports by people with MS indicated that venom immunotherapy is effective. Those supporting the study of this therapy include the Multiple Sclerosis Association of America and the American Apitherapy Society. As of June 2000, it remains to be seen whether bee venom immunotherapy is effective.

Training and certification

Although a doctor can administer bee venom therapy, no specific training or certification is required to perform the therapy. Training in handling bees is recommended. Organizations such as the American Apitherapy Society can provide information about training and therapy providers.

Vegetarianism

Vegetarianism refers to voluntary abstinence from eating meat. Vegetarians refrain from eating meat for various reasons, including religious, health, and ethical ones. Lacto-ovo vegetarians supplement their diet with dairy (lactose) products and eggs (ovo). Vegans (pronounced vee-guns) do not eat any animal-derived products at all.

Origins

The term vegetarian was coined in 1847 by the founders of the Vegetarian Society of Great Britain, but vegetarianism has been around as long as people have created diets. Some of the world’s oldest cultures advocate a vegetarian diet for health and religious purposes. In India, millions of Hindus are vegetarians because of their religious beliefs.

One of the ancient mythological works of Hinduism, the Mahabharata, states that, “Those who desire to possess good memory, beauty, long life with perfect health, and physical, budbahasa and spiritual strength, should abstain from animal foods.” The yoga system of living and health is vegetarian, because its dietary practices are based on the belief that healthy food contains prana.


Prana is the universal life energy, which yoga experts believe is abundant in fresh fruits, grains, nuts and vegetables, but absent in meat because meat has been killed. Yogis also believe that spiritual health in influenced by the practice of ahimsa, or not harming living beings.

The principle of ahimsa (non-violence) appears in the Upanishads (Vedic literature) from c. 600–300 B.C. Taking of animal life or human life under any circumstances is sinful and results in rebirth as a lower organism. It became a fundamental element of Jainism, another religion of India.

Some Buddhists in Japan and China are also vegetarian because of spiritual beliefs. In the Christian tradition, the Trappist Monks of the Catholic Church are vegetarian, and some vegetarians argue that there is evidence that Jesus and his early followers were vegetarian.

Other traditional cultures, such as those in the Middle East and the Mediterranean regions, have evolved diets that frequently consist of vegetarian foods. The Mediterranean diet, which a Harvard study declared to be one of the world’s healthiest, is primarily, although not strictly, vegetarian.

The list of famous vegetarians forms an illustrious group. The ancient Greek philosophers, including Socrates, Plato, and Pythagoras, advocated vegetarianism.

In modern times, the word to describe someone who likes to feast on food and wine is “epicure,” but it is little known that Epicurus, the ancient philosopher, was himself a diligent vegetarian. Other famous vegetarians include Leonardo da Vinci, Sir Isaac Newton, Leo Tolstoy, Ralph Waldo Emerson, and Henry Thoreau.

Vegetarianism and your health

This century’s celebrated vegetarians include Gandhi, the physician Albert Schweitzer, writer George Bernard Shaw, musician Paul McCartney, and champion triathlete Dave Scott. Albert Einstein, although not a strict vegetarian himself, stated that a vegetarian diet would be an evolutionary step for the human race.

Vegetarianism in America received a lot of interest during the last half of the nineteenth century and the beginning of the twentieth century, during periods of experimentation with diets and health practices. Vegetarianism has also been a religious practice for some Americans, including the Seventh-day Adventists, whose lactoovo vegetarian diets have been studied for their health benefits.

Vegetarianism has been steadily gaining acceptance as an alternative to the meat-and-potatoes bias of the traditional American diet. In 1992, Vegetarian Times magazine performed a poll that showed that 13 million Americans, or 5% of the population, identified them-selves as vegetarians.

Several factors contribute to the interest in vegetarianism in America. Outbreaks of food poisoning from meat products, as well as increased concern over the additives in meat such as hormones and antibiotics, have led some people and professionals to question meat’s safety. There is also an increased awareness of the questionable treatment of farm animals in factory farming.

But the growing health consciousness of Americans is probably the major reason for the surge in interest in vegetarianism. Nutrition experts have built up convincing evidence that there are major problems with the conventional American diet, which is centered around meat products that are high in cholesterol and saturated fat and low in fiber.

Heart disease, cancer, and diabetes, which cause 68% of all deaths in America, are all believed to be influenced by this diet. Nutritionists have repeatedly shown in studies that a healthy diet consists of plenty of fresh vegetables and fruits, complex carbohydrates such as whole grains, and foods that are high in fiber and low in cholesterol and saturated fat.

Vegetarianism, a diet that fulfills all these criteria, has become part of many healthy lifestyles. In alternative medicine, vegetarianism is a cornerstone dietary therapy, used in Ayurvedic medicine, detoxification treatments, macrobiotics, the Ornish diet for heart disease, and in therapies for many chronic conditions.

Benefits

Vegetarianism is recommended as a dietary therapy for a variety of conditions, including heart disease, high cholesterol, type 2 diabetes, and stroke. Vegetarianism is a major dietary therapy in the alternative treatment of cancer.

Other conditions treated with a dietary therapy of vegetarianism include obesity, osteoporosis, arthritis, allergies, asthma, environmental illness, hypertension, gout, gallstones, hemorrhoids, kidney stones, ulcers, colitis, premenstrual syndrome, anxiety, and depression. Vegetarians often report higher energy levels, better digestion, and mental clarity. Vegetarianism is an economical and easily implemented preventative practice as well.

Preparations

Some people, particularly those with such severe or chronic conditions as heart disease or cancer, may be advised by a health practitioner to become vegetarian suddenly. For most people, nutritionists recommend that a vegetarian diet be adopted gradually, to allow people’s bodies and lifestyles time to adjust to new eating habits and food intake.

Some nutritionists have designed transition diets to help people become vegetarian in stages. Many Americans eat meat products at nearly every meal, and the first stage of a transition diet is to substitute just a few meals a week with wholly vegetarian foods. Then, particular meat products can be slowly reduced and eliminated from the diet and replaced with vegetarian foods.

Red meat can be reduced and then eliminated, followed by pork, poultry, and fish. For those wishing to become strict vegetarians or vegans, the selesai step would be to substitute eggs and dairy products with other nutrient-rich foods.

Individuals should be willing to experiment with transition diets, and should have patience when learning how to combine vegetarianism with such social activities as dining out. Fortunately, the number of restaurants that offer vegetarian dishes, or even all-vegetarian menus, is growing in the United States, particularly along the West Coast.

The transition to vegetarianism can be smoother for those who make informed choices with dietary practices. Sound nutritional guidelines include decreasing the intake of fat, increasing fiber, and emphasizing fresh fruits, vegetables, legumes, and whole grains in the diet while avoiding processed foods and sugar.

Everyone can improve their health by becoming familiar with recommended dietary and nutritional practices, such as reading labels and understanding such basic nutritional concepts as daily requirements for calories, protein, fat, and nutrients. Would-be vegetarians can experiment with meat substitutes, foods that are high in protein and essential nutrients. Thanks to the growing interest in vegetarianism, many meat substitutes are now readily available.

Tofu and tempeh are products made from soybeans that are high in protein, calcium, and other nutrients. There are “veggie-burgers” that can be grilled like hamburgers, and vegetarian substitutes for turkey and sausage with surprisingly authentic textures and taste. There are many vegetarian cookbooks on the market as well.

A set of guidelines for North American vegetarian diets, updated for 2004, is available from the American Dietetic Association and the Dietitians of Canada. The new guidelines are intended to promote variety within vegetarian diets and to meet the needs of different stages in the life cycle as well as incorporate the most recent findings of medical research.

One remaining drawback to the widespread practice of vegetarianism is the unpleasant taste or smell of many vegetables. A number of phytonutrients have a bitter, astringent, or acrid taste that they impart to products made from vegetables that contain them.

Some experts think that people tend to reject such strong-smelling or bitter-tasting vegetables as turnips, cabbage, brussels sprouts, or broccoli because humans have been programmed in the course of evolution to associate bitter taste with poisonous plants. It is increasingly recognized that the major barrier to dietary change for the sake of health is taste.

One recommendation for improving the taste appeal of vegetarian diets is more frequent use of spices. In addition to pleasing the human palate, spices derived from plants have been shown to have chemoprotective effects, boosting the immune system, reducing inflammation, and fighting harmful bacteria and viruses.

Precautions

In general, a well-planned vegetarian diet is healthful and safe; in the summer of 2003, a position paper endorsed by the American Dietetic Association and the Dietitians of Canada referred to vegetarian diets as “healthful, nutritionally adequate, and [able to] provide health benefits in the prevention and treatment of certain diseases.”

However, vegetarians, and particularly vegans who eat no animal products, should be aware of particular nutrients that may be lacking in non-animal diets. These are amino acids, vitamin B₁₂, vitamin D, calcium, iron, zinc, and essential fatty acids. Furthermore, pregnant women, growing children, and those with health conditions have higher requirements for these nutrients.

Vegetarians should be aware of getting complete protein in their diets. A complete protein contains all of the essential amino acids, which are the building blocks for protein essential to the diet because the body cannot make them.

Meat and dairy products generally contain complete proteins, but most vegetarian foods such as grains and legumes contain incomplete proteins, lacking one or more of the essential amino acids. However, vegetarians can easily overcome this by combining particular foods in order to create complete proteins.

For instance, beans are high in the amino acid lysine but low in tryptophan and methionine, but rice is low in lysine and high in tryptophan and methionine. Thus, combining rice and beans makes a complete protein. In general, combining legumes such as soy, lentils, beans, and peas with grains like rice, wheat, or oats forms complete proteins.

Eating dairy products or nuts with grains also makes proteins complete. Oatmeal with milk on it is complete, as is peanut butter on whole wheat bread. Proteins do not necessarily need to be combined in the same meal, but generally within four hours.

Getting enough vitamin B₁₂ may be an issue for some vegetarians, particularly vegans, because meat and dairy products are the main sources. Vitamin supplements that contain vitamin B₁₂ are recommended, particularly for older vegetarians. Spirulina, a nutritional supplement made from algae, is also a vegetarian source, as are fortified soy products and nutritional yeast.

Vitamin D can be obtained by vitamins, fortified foods, and sunshine. Calcium can be obtained in enriched tofu, seeds, nuts, legumes, dairy products, and dark green vegetables including broccoli, kale, spinach, and collard greens.

Iron is found in raisins, figs, legumes, tofu, whole grains (particularly whole wheat), potatoes, and dark green leafy vegetables. Iron is absorbed more efficiently by the body when iron-containing foods are eaten with foods that contain vitamin C, such as fruits, tomatoes, and green vegetables.

Zinc is abundant in nuts, pumpkin seeds, legumes, whole grains, and tofu. For vegetarians who don’t eat fish, getting enough omega-3 essential fatty acids may be an issue, and supplements such as flaxseed oil should be considered, as well as eating walnuts and canola oil.

Vegetarians do not necessarily have healthier diets. Some studies have shown that some vegetarians consume large amounts of cholesterol and saturated fat. Eggs and dairy products contain cholesterol and saturated fat, while nuts, oils, and avocados are vegetable sources of saturated fat.

To reap the full benefits of a vegetarian diet, vegetarians should be conscious of cholesterol and saturated fat intake. Vegetarians may also consider buying organic foods, which are grown without the use of synthetic chemicals, as another health precaution.

Lastly, consuming large quantities of vegetables without other carbohydrates and sources of protein can produce its own kind of dietary imbalance. Cases have been reported of carotenemia, which is a yellowish discoloration of the skin caused by high levels of carotene, a fat-soluble plant pigment turned into vitamin A in the liver.

In one instance, the patient developed blood carotene levels nine times higher than normal values after putting himself on a diet that involved eating 2–3 pounds of vegetables every day. While carotenemia resulting from high vegetable intake has no known lasting consequences to health, it is still an indication of the importance of balance in vegetarian diets.

Research and general acceptance

A vegetarian diet has many well-documented health benefits. It has been shown that vegetarians have a higher life expectancy, as much as several years, than those who eat a meat-centered diet.

The U.S. Food and Drug Administration (FDA) has stated that data have shown vegetarians to have a strong or significant probability against contracting obesity, heart disease, lung cancer, colon cancer, alcoholism, hypertension, diabetes, gallstones, gout, kidney stones, and ulcers. However, the FDA also points out that vegetarians tend to have healthy lifestyle habits, so other factors may contribute to their increased health besides diet alone.

Vegetarianism has been associated with for many decades with abstinence from other habit-forming substances, including alcohol and tobacco. There is evidence, however, that this long-standing connection between vegetarianism and other health-conscious practices is breaking down.

A recent study of Scandinavian teenage vegetarians found that there was no difference between their lifestyles and those of meat-eating peers with regard to smoking, alcohol consumption, exercise, or weight. Partly because of this trend, physicians in family practice as well as those in sports medicine are increasingly recommending nutritional counseling for vegetarian teens.

A vegetarian diet, as prescribed by Dr. Dean Ornish, has been shown to improve heart disease and reverse the effects of atherosclerosis, or hardening of the arteries. It should be noted that Dr. Ornish’s diet was used in conjunction with exercise, stress reduction, and other holistic methods. The Ornish diet is lacto-ovo vegetarian, because it allows the use of egg whites and non-fat dairy products.

Vegetarians have a resource of statistics in their favor when it comes to presenting persuasive arguments in favor of their eating habits. Vegetarians claim that a vegetarian diet is a major step in improving the health of citizens and the environment.

Americans eat over 200 lbs (91 kg) of meat per person per year. The incidence of heart disease, cancer diabetes, and other diseases has increased along with a dramatic increase in meat consumption during the past century.

Many statistics show significantly smaller risks for vegetarians contracting certain conditions. The risks of women getting breast cancer and men contracting prostrate cancer are nearly four times as high for frequent meat eaters as for those who eat meat sparingly or not at all.

For heart attacks, American men have a 50% risk of having one, but the risk drops down to 15% for lacto-ovo vegetarians and to only 4% for vegans. For cancer, studies of populations around the world have implied that plant-based diets have lower associated risks for certain types of cancer.

Vegetarians claim other reasons for adopting a meat-free diet. One major concern is the amount of pesticides and synthetic additives such as hormones that show up in meat products.

Chemicals tend to accumulate in the tissue of animals that are higher in the food chain, a process called bioaccumulation. Vegetarians, by not eating meat, can avoid the exposure to these accumulated toxins, many of which are known to influence the development of cancer.

One study showed that DDT, a cancercausing pesticide, was present in significant levels in mother’s milk for 99% of American women, but only 8% of vegetarian women had significant levels of the pesticide. Women who eat meat had 35 times higher levels of particular pesticides than vegetarian women.

The synthetic hormones and antibiotics added to American cattle has led some European countries to ban American beef altogether. The widespread use of antibiotics in livestock has made many infectious agents more resistant to them, making some diseases harder to treat.

Vegetarians resort to ethical and environmental arguments as well when supporting their food choices. Much of U.S. agriculture is dedicated to producing meat, which is an expensive and resource-depleting practice.

It has been estimated that 1.3 billion people could be fed with the grain that America uses to feed livestock, and starvation is a major duduk perkara in world health. Producing meat places a heavy burden on natural resources, as compared to growing grain and vegetables.

One acre of land can grow approximately 40,000 lbs (18,000 kg) of potatoes or 250 lbs (113 kg) of beef, and it takes 50,000 gal (200,000 l) of water to produce 1 lb (0.45 kg) of California beef but only 25 gal (100 l) of water to produce 1 lb (0.45 kg) of wheat.

Half of all water used in America is for livestock production. Vegetarians argue that the American consumption of beef may also be contributing to global warming, by the large amounts of fossil fuels used in its production.

The South American rainforest is being cleared to support American’s beef consumption, as the United States yearly imports 300 million lbs (136 million kg) of meat from Central and South America. The production of meat has been estimated as causing up to 85% of the loss of topsoil of America’s farmlands.

A German researcher in the field of nutrition ecology has summarized the environmental benefits of vegetarian diets: “Research shows that vegetarian diets are well suited to protect the environment, to reduce pollution, and to minimize global climate changes.”

Despite the favorable statistics, vegetarianism does have its opponents. The meat industry in America is a powerful organization that has spent millions of dollars over decades advertising the benefits of eating meat.

Vegetarians point out that life-long eating habits are difficult to change for many people, despite research showing that vegetarian diets can provide the same nutrients as meat-centered diets.