Vitamin and mineral supplements for healthy individuals don't work

When I was in medical school, our nutrition researchers taught us that vitamins didn’t do much good and only made expensive urine (where the water soluble ones end up). We did learn about the classic vitamin deficiencies like scurvy, beriberi, rickets, etc. But the evidence that healthy people should take vitamins was marginal at best.

Is our search for immortality the reason that we turn to the pill or potion? Do we continue to look for the fountain of youth that is attached to the Spanish explorer Juan Ponce de Leon? (Though de Leon was really looking for the isle of Bimini rather than Florida and there’s no mention historically that he was searching for perpetual youth.) Yet the myth and tourist site remain popular.

So why do we turn to vitamins, supplements, anti-oxidants, nutriments, etc? William Osler commented that “the desire to take medicine is perhaps the greatest feature which distinguishes man from animals.” Also Osler taught his medical students, “One of the first duties of the physician is to educate the masses not to take medicine.”

Osler’s concerns have been valid over the years, but often have been drowned out by errant science and the hype of the vitamin and supplement industry.

There have been prominent scientists who have been strong proponents of vitamins and supplements. Linus Pauling discovered the structure of ascorbic acid (vitamin C) and won the Nobel Prize in Chemistry. Unfortunately he became a “true believer” in vitamin C and other vitamins:

Pauling is largely responsible for the widespread misbelief that high doses of vitamin C are effective against colds and other illnesses. In 1968, he postulated that people’s needs for vitamins and other nutrients vary markedly and that to maintain good health, many people need amounts of nutrients much greater than the Recommended Dietary Allowances (RDAs). And he speculated that megadoses of certain vitamins and minerals might well be the treatment of choice for some forms of mental illness. He termed this approach “orthomolecular,” meaning “right molecule.” After that, he steadily expanded the list of illnesses he believed could be influenced by “orthomolecular” therapy and the number of nutrients suitable for such use. No responsible medical or nutrition scientists share these views.

Finally in modern times we now have a better view and summary of the ineffectiveness and harms of vitamins and mineral supplements published in the Annals of Internal Medicine: “Vitamin and Mineral Supplements in the Primary Prevention of Cardiovascular Disease and Cancer: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force”.

The bottom line is that vitamin and mineral supplements for healthy individuals don’t work and some may be harmful. The editorial in the same issue concludes:

β-carotene, vitamin E, and possibly high doses of vitamin A supplements are harmful. Other antioxidants, folic acid and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases. Although available evidence does not rule out small benefits or harms or large benefits or harms in a small subgroup of the population, we believe that the case is closed— supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful. These vitamins should not be used for chronic disease prevention. Enough is enough.

Jim deMaine is a pulmonary physician who blogs at End of Life – thoughts from an MD.