2011-09-03 / Columnists

Maintaining Your Health on Mackinac

How Important Are Vitamins, Supplements, and Antioxidants?
By Yvan Silva, M.D.

Many folks believe that adding vitamins to their food intake will increase their energy. When asked to define a vitamin, the answers tend toward ambiguity.

In 1911, the first vitamin, vitamin B1, a crystalline substance, was discovered in rice husks after polishing refined the kernels. Much earlier, as English sailors on long voyages kept returning with scurvy, a severe vitamin C deficiency, a naval physician discovered that if they were fed limes (oranges) on board, the disease was preventable. This is why, even today, the Brits are sometimes called limeys. Vitamin C, in good supply in citrus fruit, is today’s much touted preventive for the common cold. There is a rich history in the discoveries and the importance of vitamins in human nutrition, many fallacies, and much controversy, and for many, dogmatic beliefs as strong as religion. Indeed, millions of Americans pop vitamin pills on a regular basis in hopes of preventing cancer, preserving vision, finding more energy, and postponing the effects of aging.

In minute quantities, these naturally occurring substances, known as vitamins, are essential for normal growth and maintenance of normal health. Vitamins do not provide energy for the body, but they do participate in biochemical reactions that create energy; they are indispensable for certain functions, and deficiencies take long periods of time to manifest as disease states. Vitamins are organic compounds that cannot be synthesized by the human body; vitamin deficiencies are associated with extremely low levels in the body, and poor intake of some vitamins can affect resistance to infection, proper healing of tissues, and increased risk for diseases such as cancer, osteoporosis, and heart disease. In most developed societies, classic deficiencies diseases like pellagra, scurvy, and beriberi do not exist because of adequate nutrition; however, elderly patients, hospitalized individuals with severe acute illnesses, and alcohol and drugdependent individuals are particularly at risk for deficiencies of certain groups of vitamins. People with chronic conditions such as cancer, cardiovascular disease, and osteoporosis may suffer inadequate intake or subtle deficiencies. Pregnancy and alcohol use may increase vitamin requirements.

At least 30% of Americans use vitamin supplements and a whole variety of other organic, mineral, and synthetic supplements regularly. Also, United States physicians and other health care practitioners are becoming better informed about the forms of vitamins available in order to effectively counsel their patients. On balance, it is important that patients comply, work with their doctors, and inform them of any and all supplements they’re taking because of the potential for side effects and drug interactions. In the case of surgery and anesthesia, this information can be vital.

“Essential” vitamins are well known. They are differentiated as fat-soluble - A, D, E, and K, or water soluble - components of the B complex, C, and others. Each of these takes part in specific systemic functions, which are essential for normalcy.

There is a Recommended Daily Allowance (RDA) defined for each. Nutrition experts continue to maintain that people should make every effort to get their essential nutrients, that is vitamins and elemental supplements, from a balanced diet with lots of fruits, vegetables, and grains. In an older study of 10,000 people followed over 13 years, 68% did not take vitamins, 22% did so regularly, and 10% occasionally. There was no evidence of increasing longevity in the vitamin takers. A recent survey showed that 32% of men and 45% of women take vitamins and other supplements regularly, such as calcium, iron, selenium, zinc, and other trace elements. Manufacturers are free to sell any formulation or combination of these substances, and there are folks walking around taking hundreds and thousands of times the RDA. Vitamin B6, for example, is sold in 500 mg. tablets, although the RDA is 2 mg. for men and 1.6 mg. for women.

More than $3 billion is spent yearly on nutritional supplements, the prevalent thinking being more is better and much more may be even better than that. The science of nutrition, even in this modern age, has not been fully charted and many side effects have not yet been linked to mega dosing of vitamins and minerals. The effects may go unnoticed, and very large doses are known to be pharmacologic, that is, they may act as drugs instead of nutrients. Millions of people take vitamin C supplements, at widely varying doses, up to thousands of milligrams a day. (The RDA is 60 mg.) Sudden withdrawal of huge doses can create a rebound deficiency, bleeding gums, reduced healing, and skin problems, but examples of this are rare. Abdominal symptoms are common with such mega doses. Niacin, which is capable of lowering cholesterol in high doses, can also cause liver damage. The list of deleterious effects of mega dosing continues to grow.

There continues to be plenty of talk about antioxidant vitamins. The theory was introduced more than a decade ago, with many promises of biological betterment. These have been identified as vitamin E, C, and beta-carotene - a plant form and precursor of vitamin A. So called “free” oxygen radicals are natural by-products of several biological processes in our bodies, and also result from exposure to environmental factors such as tobacco smoke and radiation. These oxygen compounds cause cell damage and degenerative changes in the body. Antioxidant vitamins are said to act by mopping up the activated oxygen of these free circulating radicals, which renders them ineffective in creating the cellular damage that can lead to cancers, cardiovascular disease, cataracts, and decline of the immune system.

An appropriate intake of these vitamins may act as a preventive against these and perhaps other diseases. Ideally, these vitamins should come entirely or mainly from the diet rather than pills. Supplements, again, cannot substitute for healthy eating.

Vitamin A (retinol) is important for vision, especially night vision, maintenance of a healthy immune system, and cell growth. Many precursors of A, called carotenoids, act as antioxidants (as do C and E), which help prevent cell damage and prostate and breast cancers. They are found in carrots, pumpkins, and many fruits and vegetables. Vitamin A is abundant in organ meat, fish, and dairy products. Excessive doses (as supplements) can be toxic to the liver, cause visual problems, and result in hip fractures. Excessive supplements of carotenoids can cause yellowing of skin. Folate (folic acid), a B-compound helps prevent birth defects, and is especially recommended for women who are trying to conceive or are pregnant in doses of 800 micrograms of folate daily, before pregnancy occurs. Vitamin B6 (pyridoxine) and B12 (cyanocobalamin) are important for nervous system and cellular functions and for blood cell manufacture and function – B12 deficiency can occur owing to stomach or intestinal malabsorption. Vitamin C promotes wound healing and absorption of iron. Vitamin D (calciferol) prevents osteoporosis and bone fractures. Excessive use can cause abnormal calcium deposits. Vitamin E (tocopherol) helps prevent arterial blockage. Headache, diarrhea, and fatigue can result from overuse. Vitamin K promotes normal blood clotting and bone health. All these vitamins are abundant and available in the variety of food sources described earlier.

Here is a list of recommended daily intakes of vitamins: A- 5,000 IU (international units); C-60 milligrams; D-400 IU; E- 30 IU; K-80 micrograms; B6-2 milligrams; B12-6 micrograms; Folate-400 micrograms; Thiamine 1.5 milligrams; riboflavin 1.7, and niacin 20 milligrams.

In reality, normal healthy individuals are unlikely to suffer vitamin deficiencies. However, the science of vitamin supplementation for chronic disease prevention is in evolution and knowledge of the clinical effects of vitamins is growing rapidly. It is important for you to keep up with relevant information. Remember that Web sources can be promotional and self-serving and that working closely with your doctor in the proper selection and the doses of vitamins and other supplements can be safe and optimal for maintenance of your health.

The bottom line? There are several pros and cons. The professional consensus has indeed shifted forward from the previous resistance to adamant advice against vitamin supplements, and health care experts are now saying that some people should probably take a multiple vitamin mineral supplement daily, especially those on low-calorie intakes, heavy smokers, drinkers, patients with intestinal absorption problems, and poorly nourished elderly people. Calcium supplementation is recommended for women who may not be getting enough of the mineral through the diet. Recent studies have shown, one after another, that adequate vitamins can indeed boost the state of your health and that supplements are becoming increasingly popular; combined with commonsense principles of a well balanced diet, avoidance of injurious substances and regular exercise, you can look forward to a good quality of life without any guarantees that you will live longer. For many adults, following these principles may well be better than looking to find most of their needs in bottles.

Dr. Silva is a professor of surgery at Wayne State University and a resident of Woodbluff on Mackinac Island.

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