Vitamin D status and its interaction with genetic profile on risk of type 2 diabetes in Norwegian adults - the HUNT Study

Objective: The aim of the study was to investigate the relationship between serum 25-hydroxyvitamin D [25(OH)D] level and risk of type 2 diabetes mellitus (T2DM) in adults participating in the Nord-Trøndelag Health Study (HUNT) over 11 years of follow-up. We also evaluated if sex, body mass index (BMI) and genetic profile for T2DM had potential interactions with low vitamin D levels on the risk of T2DM. Introduction: With more than 400 million people affected globally, diabetes has been identified by the United Nations as one of the four high priority non-communicable diseases targeted for action. Meanwhile, low vitamin D status remains a potential threat to health globally and has been associated with many diseases. However, its potential harmful effect on risk of diabetes is inconclusive. Methods: This prospective cohort study included 3 586 diabetes-free adults at baseline. They were ≥19 years of age and participated in the second and third surveys of the Nord-Trøndelag Health Study [HUNT2 (1995-1997), defined as the baseline, and HUNT3 (2006-2008)] in Norway. Serum 25(OH)D levels were determined at baseline and classified as