Inverse relationship between vitamin D status and insulin resistance and the risk of impaired fasting glucose in Korean children and adolescents: the Korean National Health and Nutrition Examination Survey (KNHANES) 2009–2010

To investigate whether low vitamin D status was related to insulin resistance (IR) or impaired fasting glucose (IFG) in Korean adolescents, after adjusting for total body fat mass (FM). A cross-sectional study. Korea National Health and Nutrition Examination Survey (KNAHNES) 2009-2010. In total, 1466 participants (769 males) aged 10-19 years were assessed for serum 25-hydroxyvitamin D (25(OH)D) levels, for FM by whole-body dual-energy X-ray absorptiometry and for IR by homeostasis model assessment (HOMA-IR) after an 8 h fast. Age-, sex-, season- and physical-activity-adjusted regression models showed that serum 25(OH)D levels were significantly related to markers of adiposity (P = 0.016 for FM (g), P = 0.023 for FM (%) and P = 0.035 for fat mass index). When the participants were stratified into three 25(OH)D categories (