Although >50% of U.S. adults use dietary supplements, little information is available on the impact of supplement use frequency on nutrient intakes and deficiencies. Based on nationally representative data in 10,698 adults from the National Health and Nutrition Examination Surveys (NHANES) 2009 to 2012, assessments were made of intakes from food alone versus food plus multi-vitamin/multi-mineral supplements (MVMS) of 17 nutrients with an Estimated Average Requirement (EAR) and a Tolerable Upper Intake Level (UL), and of the status of five nutrients with recognized biomarkers of deficiency. Compared to food alone, MVMS use at any frequency was associated with a lower prevalence of inadequacy (p < 0.01) for 15/17 nutrients examined and an increased prevalence of intakes >UL for 7 nutrients, but the latter was ≤4% for any nutrient. Except for calcium, magnesium, and vitamin D, most frequent MVMS use (≥21 days/30 days) virtually eliminated inadequacies of the nutrients examined, and was associated with significantly lower odds ratios of deficiency for the examined nutrient biomarkers except for iron. In conclusion, among U.S. adults, MVMS use is associated with decreased micronutrient inadequacies, intakes slightly exceeding the UL for a few nutrients, and a lower risk of nutrient deficiencies.
Keywords: NHANES; dietary supplements; micronutrient; multi-vitamin/multi-mineral; nutrient deficiencies; nutritional adequacy; nutritional supplements; vitamins.