Association between vitamin D insufficiency and risks of cardiovascular diseases (CVD) and cancer has been repeatedly reported in observational studies. A study in Finland tried to find some evidence for the benefits with vitamin D supplementation. It was a 5-year randomised placebo-controlled trial that included 2495 participants (males aged ≥ 60 and post-menopausal females aged ≥ 65) who were free of prior CVD or cancer. For investigation, there were 3 arms in the study: placebo, 1600 IU/day, and 3200 IU/day. Incidence of major CVD and invasive cancer were adopted as the primary endpoints. As a result, no significant difference in terms of CVD and cancer events was found among the groups. The conclusion was straightforward, vitamin D3 supplementation did not lower the incidence of major CVD events or any cancer. One possible explanation to the findings was the sufficient vitamin D status at baseline which in turn indicates the absence of marginal benefits of vitamin D3 supplementation if one has already got enough vitamin D from daily activities.

References

1. Virtanen JK, et al. Am J Clin Nutr. 2022:nqab419.