A systematic review and meta-analysis of circulating 25-hydroxyvitamin D concentration and vitamin D status worldwide
Eleanor Dunlop, Ngoc Minh Pham, Dong Van Hoang, Hajar Mazahery, Belinda Neo, Jillian Shrapnel, Αliki Kalmpourtzidou, Kevin Chai, Leo Ng, Lucinda J. Black
Abstract
BACKGROUND: Vitamin D deficiency is a public health concern; however, data on its global prevalence are limited. We reported pooled mean circulating 25-hydroxyvitamin D (25(OH)D) concentration and estimated the prevalence of concentration according to commonly reported thresholds for general, healthy populations worldwide. METHODS: We searched MEDLINE, Embase, Web of Science, Global Index Medicus and grey literature sites. We included cross-sectional and cohort studies published since 2011 that reported circulating 25(OH)D concentration in general, healthy populations of all ages. Using random-effects meta-analysis, we pooled data on circulating 25(OH)D concentration and prevalence estimates according to thresholds by continent, country, latitude, sex, adults/children, season, assay, and study quality. PROSPERO registration: CRD42021242466. RESULTS: Eligible publications (n = 586) included 2 370 136 eligible participants across 102 countries. The pooled mean (95% confidence interval [CI]) overall circulating 25(OH)D concentration was 53.9 (52.6-55.1) nmol/L (529 publications; 1 412 281 participants). The pooled prevalence of concentration < 30, < 50, and < 75 nmol/L was 18, 47, and 75%, respectively (403 studies; 1 508 830 participants). CONCLUSIONS: Low vitamin D status is prevalent across general, healthy populations worldwide. Governments, health organizations and policy makers could use these findings to identify regions in need of public health strategies for improving vitamin D status.