Association of hypovitaminosis D with triceps brachii muscle fatigability among older women: Findings from the EPIDOS cohort.

•Vitamin D is involved in musculoskeletal health.•We found that lower 25OHD concentrations were associated with greater muscle fatigability in older women.•This effect may underlie the involvement of vitamin D in physical performance and fall risk.•Future analyses should examine the effects of vitamin D supplementation on the ability of muscles to exert effort over time.