Is there a link between vitamin D levels and all-cause mortality?

    Written by:
    Morgan Pfiffner, Bill Willis

    Fact-checked

    by:

    Nick Milazzo
    Last Updated: May 16, 2025

    Low vitamin D levels may be associated with increased all-cause mortality, especially in older adults, as supported by observational studies and clinical trials showing reduced mortality with supplemental vitamin D3. However, randomized controlled trials in the general adult population have not confirmed an association between vitamin D supplementation and all-cause mortality, which indicates a need for further research.

    Low vitamin D levels may be linked to increased all-cause mortality, particularly in older adults. Observational studies have shown a general trend for associations between low vitamin D levels and all-cause mortality in general[1] and elderly[2] populations.

    The link between increased all-cause mortality and low vitamin D levels in elderly participants has been confirmed by clinical trials showing decreased mortality with vitamin D3 supplementation.[3]

    Although associations between low vitamin D levels and increased all-cause mortality in the general population have been reported in observational studies,[1] randomized controlled trials with adult participants 18 years or older have failed to confirm this, finding no evidence for an association between vitamin D supplementation and all-cause mortality compared to a placebo.[4]

    More research is needed to better understand the influence of vitamin D supplementation on all-cause mortality and longevity in different populations.