Association among dietary supplement use, nutrient intake, and mortality among U.S. adults: a cohort study

Authors: CHEN, FAN - Tufts University; DU, MENGXI - Tufts University; BLUMBERG, JEFFREY - Tufts University; CHUI, KENNETH - Tufts University; RUAN, MENGYUAN - Tufts University; ROGERS, GAIL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; SHAN, ZHILEI - Tufts University; ZENG, LUXIAN - Tufts University; ZHANG, FANG FANG - Tufts University

Submitted to: Annals of Internal Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2019
Publication Date: 4/9/2019
Citation: Chen, F., Du, M., Blumberg, J.B., Chui, K.K., Ruan, M., Rogers, G., Shan, Z., Zeng, L., Zhang, F. 2019. Association among dietary supplement use, nutrient intake, and mortality among U.S. adults: a cohort study. Annals Of Internal Medicine. 170(9):604-613. https://doi.org/10.7326/M18-2478.
DOI: https://doi.org/10.7326/M18-2478

Interpretive Summary: Recent studies show that more than half of U.S. adults use dietary supplements. However, there is controversy over whether dietary supplement use is associated with health benefits or risks. This study uses data from over 30,000 participants in the National Health and Nutrition Examination Survey (NHANES) to examine the association between dietary supplement use and mortality (death), cardiovascular disease (CVD), and cancer, among a nationally representative sample of U.S. adults. Results showed that history of ever using a dietary supplement was not associated with mortality. However, participants who ate the Adequate Intake of vitamin A, vitamin K, magnesium, zinc, and copper, from foods, had fewer deaths overall and fewer deaths from CVD. Excess intake of calcium was associated with increased risk of death from cancer, and the association seemed to be related to calcium intake from supplements rather than foods.

Technical Abstract: Background: The health benefits and risks of dietary supplement use are controversial. Objective: To evaluate the association among dietary supplement use, levels of nutrient intake from foods and supplements, and mortality among U.S. adults. Design: Prospective cohort study. Setting: NHANES (National Health and Nutrition Examination Survey) data from 1999 to 2010, linked to National Death Index mortality data. Participants: 30 899 U.S. adults aged 20 years or older who answered questions on dietary supplement use. Measurements: Dietary supplement use in the previous 30 days and nutrient intake from foods and supplements. Outcomes included mortality from all causes, cardiovascular disease (CVD), and cancer. Results: During a median follow-up of 6.1 years, 3613 deaths occurred, including 945 CVD deaths and 805 cancer deaths. Ever-use of dietary supplements was not associated with mortality outcomes. Adequate intake (at or above the Estimated Average Requirement or the Adequate Intake level) of vitamin A, vitamin K, magnesium, zinc, and copper was associated with reduced all-cause or CVD mortality, but the associations were restricted to nutrient intake from foods. Excess intake of calcium was associated with increased risk for cancer death (above vs. at or below the Tolerable Upper Intake Level: multivariable-adjusted rate ratio, 1.62 [95% CI, 1.07 to 2.45]; multivariable-adjusted rate difference, 1.7 [CI, -0.1 to 3.5] deaths per 1000 person-years), and the association seemed to be related to calcium intake from supplements (>/=1000 mg/d vs. no use: multivariable-adjusted rate ratio, 1.53 [CI, 1.04 to 2.25]; multivariable-adjusted rate difference, 1.5 [CI, -0.1 to 3.1] deaths per 1000 person-years) rather than foods. Limitations: Results from observational data may be affected by residual confounding. Reporting of dietary supplement use is subject to recall bias. Conclusion: Use of dietary supplements is not associated with mortality benefits among U.S. adults.