Summary from the authors: Dietary supplements are used by more than half of adults, although to our knowledge, the reasons motivating use have not been previously examined in US adults using nationally representative data. The purpose of this analysis was to examine motivations for dietary supplement use, characterize the types of products used for the most commonly reported motivations, and to examine the role of physicians and health care practitioners in guiding choices about dietary supplements. Method: Data from adults (≥20 years; n = 11 956) were examined in the 2007-2010 National Health and Nutrition Examination Survey, a nationally representative, cross-sectional, population-based survey. Results:   The most commonly reported reasons for using supplements were to “improve” (45%) or “maintain” (33%) overall health. Women used calcium products for “bone health” (36%), whereas men were more likely to report supplement use for “heart health or to lower cholesterol” (18%). Older adults (≥60 years) were more likely than younger individuals to report motivations related to site-specific reasons like heart, bone and joint, and eye health. Only 23% of products were used based on recommendations of a health care provider. Multivitamin-mineral products were the most frequently reported type of supplement taken, followed by calcium and ω-3 or fish oil supplements. Supplement users are more likely to report very good or excellent health, have health insurance, use alcohol moderately, eschew cigarette smoking, and exercise more frequently than nonusers.

Citation: Bailey RL et al. Why US adults use dietary supplements. JAMA Intern Med 2013 Feb 4;

Comments: Large study with somewhat surprising results: the percentage of people using vitamins, characteristics of users and the reason(s) given for that use. In addition, the choice of the supplement is not done with consultation with a physician; actually, how many supplement users tell their physicians what they actually take? Not all supplements are harmless; some interaction with prescribed medications have been reported and then the “too much of a good thing” (see previous posting). The supplement business is a $28 billion a year_BA

Calcium intake, both dietary and supplemental, is encouraged to improve bone health, and many older adults take calcium supplements. Recent randomized trials of supplementation suggest an association with cardiovascular disease (CVD), but the studies are heterogeneous, and results are mixed. In this prospective cohort study, U.S. researchers assessed baseline calcium intake — including dietary recall and calcium supplements and calcium-containing antacids and multivitamins — in 390,000 older adults (mean age, 61). About 50% of men and 70% of women used calcium-containing supplements. Median daily dietary intake of calcium in both men and women was 700 mg. During 12 years of follow-up, researchers identified 12,000 CVD-related deaths. In analyses adjusted for multiple CVD risk factors, supplemental calcium was associated significantly with CVD-related death in men but not in women: In men, daily calcium supplementation of >1000 mg, compared with no supplement use, was associated with 20% higher risk for CVD-related death, with the excess risk entirely attributable to heart disease. Calcium intake was not associated with death from cerebrovascular disease.

Published in Journal Watch

Comments: A large trial over a long period of time with convincing results, although somewhat puzzling Men but not women? Heart but not brain? How much is safe for men (should men take it? what age?) BA

Citation: Xiao Q et al. Dietary and supplemental calcium intake and cardiovascular disease mortality: The National Institutes of Health–AARP Diet and Health study. JAMA Intern Med 2013 Feb 4;