Crazy about Vitamins

Abstract

One half of Americans take vitamins regularly, according to a Gallup poll (Swift, 2013). Indeed, 78 percent agree that “dietary supplements are a smart choice for a healthy lifestyle” (Council for Responsible Nutrition, 2015). People seem crazy about vitamins (Figure 1). Figure 1. Vitamins—and more vitamins. But does this mean that the population is well informed about the biological function of vitamins, or that such knowledge guides personal decision making about nutrition and health? Perhaps not. Reliance on supplements might actually indicate a poor basic understanding of a complete and balanced diet. Taking high doses of vitamins may also reflect unjustified beliefs about their power in curing various maladies, despite the lack of any substantive scientific evidence. Perhaps we might unravel the pervasive Sacred Bovine that vitamins have some extraordinary powers beyond their very particular nutritional roles? No biologist, surely, will question the general importance of vitamins or the diseases—such as beriberi, scurvy, or pellagra—that result from their deficiencies. “For example,” as the National Institutes of Health notes, “calcium and vitamin D are important for keeping bones strong and reducing bone loss; folic acid decreases the risk of certain birth defects; and omega-3 fatty acids from fish oils might help some people with heart disease” (Office of Dietary Supplements, 2011). In these cases, the molecular mechanisms involving the vitamins are well known. But at other times, claims about the efficacy of vitamins are speculative or with no scientific grounding whatsoever. Yet such unfounded beliefs proliferate. Sometimes, with great conviction. Indeed, people can be “crazy” about vitamins. How does such trenchant dismissal of science originate? Why does it persist? One might gain insight from the history of vitamin C and its purported role in fighting the common cold. For many years, popular belief (sometimes masquerading as conventional wisdom) was that megadoses of …