Vitamin and dietary supplements are not associated with total or cardiovascular mortality in Switzerland: the CoLaus|PsyCoLaus prospective study.

Abstract

Purpose: Vitamin-mineral and dietary supplements (VMDS) are taken by a large fraction of the population. Whether their long-term consumption impacts mortality and cardiovascular disease (CVD) has seldom been studied.

Methods: Prospective study from a population-based cohort from Lausanne, Switzerland. Participants were categorized as non-users (no consumption at baseline and first follow-up), persistent users (consumption at baseline and follow-up), and occasional users (consumption either at baseline or follow-up). Incidence of CVD and of total mortality was assessed after the first follow-up.

Results: Data from 4261 participants (57.4 ± 10.4 years, 55% females) was used. Median follow-up was 9 years (interquartile range 7.0-9.2) After multivariable analysis, no association was found between VMDS use and total mortality: hazard ratio and (95% confidence interval) 0.95 (0.71-1.28) and 0.83 (0.55-1.26) for occasional and persistent consumers, respectively, CVD mortality: 1.00 (0.47-2.11) and 1.30 (0.53-3.18), or CVD events: 0.96 (0.72-1.27) and 0.95 (0.64-1.42). Similar findings were obtained after inverse probability weighting, using only vitamin-mineral supplement users, or considering only participants at baseline. When CVD events were split into coronary heart disease (CHD) or stroke, persistent use of VMDS was associated with a higher risk of CHD in females: 3.12 (1.52-6.41), p = 0.002, but not in males, 0.25 (0.03-1.82), p = 0.171, p for interaction < 0.05. No association was found between VMDS use and incidence of stroke in both sexes.

Conclusion: We found no association between vitamin and dietary supplement use and total or CVD mortality, or CVD events. The higher risk of CHD for persistent use in females should be further explored.