Serum Vitamin D concentrations in baboons (Papio spp.) during pregnancy and obesity

Obesity is associated with Vitamin D deficiency, which can lead to serious problems during pregnancy. However, the mechanisms of the deficiency and guidelines for Vitamin D supplementation during pregnancy are not established yet, and variations in environmental exposures combined with the difficulties of performing research in pregnant women are obstacles in the evaluation of Vitamin D metabolism. Baboons (Papio spp.) are an excellent, well-established model for reproductive research and represent a unique opportunity to study Vitamin D metabolism in a controlled environment. This study used secondary data and specimen analysis as well as a novel experimental design to evaluate pregnant and nonpregnant baboons that were or were not exposed to sunlight while they were obese and after weight reduction. Daily D3 intake was 71% higher in nonpregnant obese baboons than in their nonobese counterparts, but serum Vitamin D concentrations did not differ between these populations. In addition, serum 25-hydroxyVitamin D concentrations correlated negatively with the obesity index. This report is the first to show the effect of obesity and pregnancy on Vitamin D concentrations in a NHP population. These data underline the importance of adequate Vitamin D supplementation in obese animals.