Endocrine Abstracts

Developmental programming of insulin resistance in the offspring of diabetic mothers have contributed significantly to the increased prevalence of type 2 diabetes mellitus and other metabolic disorders in the general population. Vitamin D has been reported to improve glucose metabolism, however its potential in reversing glucose intolerance programmed in the offspring of diabetic mothers has not been fully elucidated. The study therefore aimed to investigate the effect of vitamin D₃ supplementation on glucose tolerance in the offspring of fructose-induced diabetic Sprague-Dawley rats. Six female rats weighing 160-180g were fed on high fructose diet (25% w/v) for 12 weeks to induce hyperglycemia and hyperinsulinemia. The rats were subsequently mated after the successful induction of type 2 diabetes mellitus and were allowed to deliver at term. The offspring of the rats were weaned at 3 weeks and fed on normal rat chow till pubertal onset at 6 weeks. Separation of the offspring by sex was done and they were grouped into two namely (1) vitamin D₃ supplemented offspring, fed on a diet containing an additional 750 IU/Kg of vitamin D₃ for 6 weeks and (2) Standard rat chow fed (positive control) offspring. Oral glucose tolerance test was conducted, blood samples were obtained and assessed for fasting blood glucose, insulin, vitamin D₃ and lipid levels in both groups. Results showed that vitamin D₃ supplemented offspring of diabetic rats had a significant decrease in fasting blood glucose, insulin and triglyceride levels compared to the offspring on standard diet. Oral glucose tolerance test results also showed a significant enhancement of insulin sensitivity in the vitamin D₃ supplemented offspring compared to the positive control. These findings show that vitamin D₃ supplementation improves glucose homeostasis in the offspring of diabetic rat model.

Key words: glucose tolerance, vitamin D₃, maternal diabetes, developmental programming