Vitamin D status may influence the risk of developing metabolic diseases such as Type 2 diabetes (T2D), metabolic syndrome (MetS) and insulin resistance (IR). Several studies have assessed vitamin D in relationship with metabolic outcomes; however, results remain inconsistent. A systematic review and meta-analysis using multiple databases (MEDLINE, Web of Science and EMBASE), was performed up to 10 August 2012. Prospective studies reporting association of circulating or dietary vitamin D with incident T2D, MetS and IR outcomes were included. Relative risks (RR) were pooled using random effects and subgroup analysis by pertinent study-level characteristics was performed. A total of seventeen articles based on eighteen unique prospective studies, and comprising 210 107 participants with 15 899 metabolic events, collected during a median follow up of 10 years (range 3-22 years), were included. RR for individuals in top v. bottom thirds of baseline vitamin D were 0·81 (95% CI 0·71, 0·92); 0·86 (95% CI 0·80, 0·92); and 0·84 (95% CI 0·64, 1·12) for T2D, MetS and IR outcomes, respectively. Moderate heterogeneity was found between fourteen studies (I 2 = 67%, P < 0·001) reporting on T2D. Findings were generally consistent across various study-level characteristics. In conclusion, vitamin D status at baseline in apparently healthy adults is inversely associated with future risks of T2D and MetS. Interventions aimed at maintaining adequate levels of vitamin D in addition to preventing deficiency may be a useful preventive measure for metabolic diseases. However, reliable evidence from carefully designed intervention studies, particularly those based on healthy populations, is needed to confirm observational findings. Copyright

Additional Metadata
Keywords Insulin resistance, Metabolic syndrome, Prospective epidemiological studies, Type 2 diabetes, Vitamin D
Persistent URL dx.doi.org/10.1017/S0029665112002765, hdl.handle.net/1765/65437
Journal Nutrition Society. Proceedings
Citation
Khan, H, Kunutsor, S, Franco, O.H, & Chowdhury, R. (2013). Vitamin D, type 2 diabetes and other metabolic outcomes: A systematic review and meta-analysis of prospective studies. In Nutrition Society. Proceedings (Vol. 72, pp. 89–97). doi:10.1017/S0029665112002765