Abstract MP27: Use of Multivitamin Supplements and Risks of Total and Cause-Specific Mortality Among U.S. Adults

As the most commonly consumed dietary supplement, how multivitamin use associates with risk of mortality remains inconclusive. Methods: We used data from three cohort studies to examine the association of time-varying multivitamin use with risk of mortality. We also emulated a target trial to estimate the association by applying the parametric g-formula. Results: Of 241,068 eligible participants (mean age at baseline: 50 for NHS, 37 for NHSII, and 53 for HPFS), there were 44,415 deaths over 30-years of follow up. Compared to non-users, the pooled age-adjusted harzard ratio (HR) of mortality was 0.92 (95% CI: 0.89, 0.94) and 0.89 (95% CI: 0.88, 0.91) for users who used <1 and ≥1 pill/day, respectively. These results were attenuated after multivariable adjustment (0.97 [0.95, 1.00] and 0.98 [0.96, 0.99], respectively), and the inverse association was primarily due to lower risk of CVD mortality ( table 1 ). In the emulated target trial, the estimated 30-y all-cause mortality under a multivitamin intervention was slightly lower than no intervention ( table 2 ). Conclusions: Multivitamin use may relate to a small reduction in mortality among middle-aged adults.