title: Vitamin D supplementation and body weight status: a systematic review and meta-analysis of randomized controlled trials.
abstract: Vitamin D is anticipated to have many extra-skeletal health benefits. We questioned whether supplementation with the vitamin influenced body weight and composition. A systematic review and meta-analysis was conducted on high-quality, randomized controlled trials (RCTs) that had supplemented vitamin D without imposing any caloric restriction. Eighteen trials reporting either body weight, body mass index (BMI), fat mass (FM), percentage fat mass (%FM) or lean body mass (LBM) met our criteria. Twelve studies provided the required data for the meta-analysis. Vitamin D supplementation did not influence the standardized mean difference (SMD) for body weight, FM, %FM or LBM. A small but non-significant decrease in BMI (SMD = -0.097, 95% confidence interval: [-0.210, 0.016], P = 0.092) was observed. Meta-regression confirmed that neither the absolute vitamin D status achieved nor its change from baseline influenced the SMD of any obesity measure. However, increasing age of the subjects predicted a shift in the SMD for FM towards the placebo treatment, whereas a greater percentage of women in these studies favoured a decrease in FM following vitamin D. Vitamin D supplementation did not decrease measures of adiposity in the absence of caloric restriction. A potential confounding by age and gender was encountered.
authors: Department of Nutrition, Dietetics & Food Science, School of Public Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia.
authors: K
authors: K
authors: Pathak
authors: M J
authors: MJ
authors: Soares
authors: E K
authors: EK
authors: Calton
authors: Y
authors: Y
authors: Zhao
authors: J
authors: J
authors: Hallett
mesh_terms: D050154:Adiposity; D000367:Age Factors; D000368:Aged; D001823:Body Composition / Q000187:drug effects; D015992:Body Mass Index; D001835:Body Weight; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D016032:Randomized Controlled Trials as Topic; D012737:Sex Factors; D014807:Vitamin D / Q000008:administration & dosage*
chemical_list: D010919:Placebos; D014807:Vitamin D
keywords: Obesity; supplementation; vitamin D