A pilot study investigating the effect of serum 25-hydroxyvitamin D on device-estimated sleep metrics in young black women: a single-arm open-label clinical trial

Abstract

Study Objectives Vitamin D deficiency has been linked to poor sleep health outcomes in the general population. Black women (BLW) experience a higher prevalence of vitamin D deficiency and short and disturbed sleep compared with other races. Therefore, this study tested cross-sectional associations between serum 25-hydroxyvitamin D concentration ([25(OH)D]) and sleep health estimates in young adult BLW, followed by an 8-week vitamin D supplementation intervention.

Materials and Methods Forty-three 18-30-year-old BLW underwent blood sampling for serum [25(OH)D]. Sleep metrics were derived from 14-days of wrist accelerometry. Thereafter, participants with [25(OH)D] <30 ng/ml (N = 16) completed an 8-week vitamin D3 supplementation intervention (5000 IU/day) and repeated blood sampling and sleep monitoring.

Results Linear regressions demonstrate significant cross-sectional associations for [25(OH)D] with sleep efficiency (β = 0.11, p = .03; %) and sleep onset standard deviation (SOSD) (β = -0.53, p = .04; minutes), but no associations with sleep duration or sleep duration standard deviation (p > .18). Among intervention participants, paired-sample t-tests demonstrate a significant increase in [25(OH)D] (16.8 ± 7.0 vs. 55.3 ± 10.0, ng/ml; p < .001), however, no changes were observed among actigraphy-derived sleep variables (all p > .21).

Conclusions [25(OH)D] was cross-sectionally associated with sleep efficiency and SOSD, however, intervention results from this pilot study do not demonstrate a beneficial effect of vitamin D on several device-estimated sleep metrics in young BLW.