Serum 25-hydroxyvitamin D concentration and its association with glucose intolerance in an indigenous population

Type 2 diabetes is a multifactorial disease resulting from diverse genetic and environmental factors as well as the interaction between them. Low levels of 25-hydroxyvitamin D [25(OH)D], an indicator of vitamin D status, have been associated with an increased risk of type 2 diabetes, but not consistently. Also, it remains to be determined if this association differs among ethnic groups. Therefore, we aimed to evaluate vitamin D status and its association with glucose intolerance in a Brazilian indigenous population, the Xavante Indians. The study population consisted of 819 full Xavante Indians (410 women), aged ≥18 years and living in two indigenous reserves located in Mato Grosso State, central region of Brazil. Clinical examination and anthropometrical measurements were made, blood samples were obtained for total cholesterol, HDL-cholesterol, triglycerides and 25(OH)D measurement. Fasting and 2-h post 75 g oral glucose load capillary glucose was measured. Vitamin D status was defined by serum 25(OH)D levels: vitamin D sufficiency (25(OH)D: 30–100 ng/mL), vitamin D insufficiency (25(OH)D: 20-