Long-term benefits of daily multivitamin use may vary by diet quality and baseline BP: Study

New research from Mass General Brigham investigators suggests that long-term multivitamin supplementation could reduce hypertension risk and blood pressure (BP) in specific groups of older adults. A secondary analysis of data from the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) found no significant effects from those randomized to daily multivitamin use versus placebo on hypertension risk or blood pressure for the overall study population. However, analyses identified small, significant improvements in study participants with lower dietary quality and normal BP at baseline. Results are published in the American Journal of Hypertension.

“Nutrition is one of the cornerstones for controlling blood pressure and hypertension. We found that a daily multivitamin might be useful for reducing the risk of hypertension in people with poorer nutritional intake,” said corresponding author Rikuta Hamaya, MD, PhD, MS, of the Division of Preventive Medicine in the Mass General Brigham Department of Medicine.

“Our findings suggest that a daily multivitamin may not be a one-size-fits-all solution for controlling blood pressure but could be beneficial for important subsets of older adults,” said corresponding and senior author Howard Sesso, ScD, MPH, of the Division of Preventive Medicine in the Mass General Brigham Department of Medicine.

COSMOS is a randomized, placebo-controlled clinical trial that investigated the effects of cocoa extract and multivitamin supplementation on health outcomes among older U.S. adults. In this study, the research team analyzed a subset of 8,905 older adults without hypertension at baseline, who took either Centrum Silver or placebo daily over a median window of 3.4 years. The researchers also evaluated blood pressure changes over two years in two groups of 529 and 994 participants, whose measurements were taken at a clinic or at home, respectively.

Overall, the investigators found no differences in self-reported incident hypertension between the multivitamin and placebo groups. Multivitamins lowered risk of hypertension in participants with comparatively lower diet quality, as measured by Alternative Healthy Eating Index (AHEI) and Alternate Mediterranean Diet (aMED) scores. In addition, participants with normal BP at baseline taking a daily multivitamin experienced small, significant reductions in BP measurements over two years.

The authors propose that further research is required to examine the effects of a daily multivitamin in younger and middle-aged adults, and across different populations based on nutritional status.

Reference:

Rikuta Hamaya, Sidong Li, Jessica Lau, Susanne Rautiainen, Bernhard Haring, Simin Liu, Aladdin H Shadyab, Lisa Warsinger Martin, Sylvia Wassertheil-Smoller, Pamela M Rist, JoAnn E Manson, Howard D Sesso, COSMOS Research Group, Long-term effect of multivitamin supplementation on incident self-reported hypertension and blood pressure changes in the COSMOS trial, American Journal of Hypertension, 2025;, hpaf224, https://doi.org/10.1093/ajh/hpaf224