Dietary Supplements: Navigating a Minefield

Hope springs eternal in the human breastA. Pope, Essay on man, Epistle i. Hope springs eternal in the human breast A. Pope, Essay on man, Epistle i. Dietary supplements refer to any substance taken in addition to regular food. Supplements include vitamins, minerals, amino acids, herbs, enzymes, and various substances extracted from plants and animals. They are sold as liquids, tablets, capsules, and powders. By definition these products are not conventional foods but are intended to supplement the diet, generally with the intent of improving health and body functioning, and of preventing or treating disease. There has been a rapid increase in recent years in the sales of dietary supplements in the USA. Much of this can be traced to the passing of the Dietary Supplement and Health Education Act (DSHEA) in 1994, a law that gave the supplement industry much wider freedom. Sales of dietary supplements in the United States doubled after the passing of this law to almost $18 billion in 2000 (Nutr Bus J, 2002) and have been steadily increasing since. Sales in the USA now total roughly $32 billion per year. Surveys reveal that around half of adults in the USA take supplements regularly (JAMA Intern Med 173:355–361, 2013; Nutritional health: strategies for disease prevention, New York, 435–449, 2012). Canadian surveys are broadly similar (Can J Public Health 93:426–430, 2002). The profiles of people most likely to use dietary supplements are female, older, white, nonsmokers, regular exercisers, and better educated (JAMA Intern Med 173:355–361, 2013; Nutritional health: strategies for disease prevention, New York, 435–449, 2012). Physicians and other health professionals need to be aware of issues related to supplements. Patients may seek advice from their physician concerning supplements. Ideally, physicians should be able to give reliable information. This does not mean that physicians should have a detailed knowledge of all supplements, but rather that they should have a good basic knowledge while also knowing where to obtain additional information. Unfortunately, most physicians receive very little training in this area.