Vitamin supplements: Are they associated with immune status?

Background & aims: Vitamins are essential nutrients, taken in very small amounts (0.01-100 mg a day). Associations between vitamin supplement intake or status and the immune system are far from consensual. Our aim was to understand the association between vitamin supplements and the immune system, namely regarding lymphocyte count and immunoglobulin levels against infectious pathogens. Methods: Cross-sectional study using data from the first follow-up of the CoLaus|PsyCoLaus study (April 2009 to September 2012). Participants were categorized as vitamin users and non-users. Serostatus for 15 viruses, six bacteria, and one parasite was assessed. Data for inflammatory markers (hs-CRP, IL-1b, IL6, and TNF-alpha) and blood elements were also collected. Results: Of the initial 5064 participants, 3769 (74.5 %, mean age 58.3 +/- 10.5 years, 53.6 % women) were retained for serostatus. On bivariate analysis, participants taking vitamins presented with higher positivity levels in three markers and lower positivity levels in two, but those differences were no longer statistically significant after multivariable analysis. 4489 participants (88.6 %, mean age 57.7 +/- 10.5 years, 53.2 % women) had data for inflammatory markers; no association was found between vitamin supplement use and inflammatory markers both on bivariate and multivariable analysis. Finally, 3349 participants (66.1 %, mean age 57.3 +/- 10.3 years, 53.1 % women) had data for blood elements; on bivariate analysis, vitamin supplement users had lower levels of haemoglobin and lymphocytes, but those differences were no longer significant after multivariable adjustment. Conclusion: In this cross-sectional, population-based study, we found no association between vitamin supplement use and markers of immune status. (c) 2024 The Author(s). Published by Elsevier Ltd on behalf of European Society for Clinical Nutrition and Metabolism.