WORLD HEALTH
By Allan R. Handysides and Peter N. Landless
Please address the confusing information regarding vitamin and other nutritional supplements. I’m especially thinking of studies that claim vitamin E is a contributing factor to cardiac disease and death (several years back), and the more recent one that claims that vitamin E supplementation noticeably increases the risk of prostate cancer in men.
This is indeed a confusing issue to many, because so many supplements make claims about their health benefits. The supplements industry is huge and very profitable. It’s estimated that more than half of all Americans take at least one supplement and spend approximately US$25 billion annually on them. Supplements of various kinds are used worldwide.
What is a supplement? It’s a substance taken by mouth but is not a food; it may be in the form of a liquid, tablet, capsule, powder, or even injection. It’s intended to add that which the diet may not be providing in sufficient quantity. Supplements may be readily purchased and generally are not tested, controlled, and regulated as are standard medications, so many of the claims regarding them haven’t been substantiated. A dietary supplement may contain a vitamin, mineral, hormone, amino acid, or plant or animal extract; in fact, it may contain anything.
There have been a number of clinical studies over the past few years to test benefits and risks.
Vitamin E has not fared well when claims of its protective benefits against heart disease and stroke were tested. In fact, it was associated with an increase in the diseases it was purported to prevent. Additionally, in the recent Selenium and Vitamin E Cancer Prevention Trial (SELECT), researchers found that vitamin E supplements may actually increase the risk of developing prostate cancer by 17 percent.
Equally surprising results were seen when beta-carotene supplements were tested on the hypothesis that they would prevent the development of cancer. The study had to be stopped prematurely because the group taking the additional beta-carotene was shown to have an increased incidence of lung cancer. Beta-carotene is a substance found in yellow vegetables and is safe when taken in the diet because it occurs naturally in yellow vegetables, but not when taken as a supplement.
The recent Iowa Women’s Health Study (about 39,000 women studied over 19 years), published in the journal Archives of Internal Medicine in late 2011, raised more concern regarding routine use of supplemental vitamins and minerals (routine meaning in the absence of specific deficiency due to disease states or dietary deficiencies). One portion of this study suggests a link between multivitamin intake and increased death rates in older women. Copper and iron supplements were also associated with this worrying trend.
In stark contrast to the above study is the startling fact that iron deficiency is the commonest nutritional deficiency in the world. Two billion people are anemic, many of them as a result of iron deficiency. Those living in developing countries would certainly benefit from appropriate iron supplementation.
So who should receive vitamin and mineral supplementation?
- Those suffering nutritional deficiencies from an inadequate diet.
- Pregnant women—folic acid supplementation has been proven to decrease neural tube deformities; also iron supplementation may be needed.
- Those with dark skin and individuals with fewer than 15 minutes of sun exposure per day may benefit from supplemental vitamin D.
- Those with gastrointestinal diseases, which cause decreased absorption of nutrients, e.g., celiac disease (gluten sensitivity).
- Those undergoing cancer treatment (chemotherapy).
Allan R. Handysides, a board-certified gynecologist,
is director of the General Conference Health Ministries Department.
Peter N. Landless, a board-certified nuclear cardiologist,
is an associate director of the General Conference Health Ministries Department.
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