Comment on: Bardenheier et al. Variation in prevalence of gestational diabetes mellitus among hospital discharges for obstetric delivery across 23 states in the United States. Diabetes Care 2013;36:1209-1214

Bardenheier et al. (1) presented data on prevalence of gestational diabetes mellitus (GDM) associated with delivery as a function of state and race. They identified a number of important risk factors including race, maternal age, state, insurance, and obesity. Overlooked in the article was any discussion of the role of vitamin D. Vitamin D deficiency is an important risk factor for GDM. A review found that “serum 25-hydroxyvitamin D (25OHD)