Effect of Vitamin D Supplementation on Glycemic Control in Children with Type 1 Diabetes Mellitus: A Randomized Clinical Trial

Abstract

Background: Vitamin D endocrine system is a potential immune system modulator and has been implicated in the pathogenesis of several autoimmune diseases including type 1 diabetes mellitus. A relationship between type 1 diabetes and vitamin D deficiency has been reported, in which low vitamin D levels are shown to have a negative effect on beta-cell function. The aims of the study were to investigate vitamin D status and to evaluate the effect of vitamin D3 supplementation on glycemic control in children with type 1 diabetes. Method: A randomized clinical trial including 80 children who were newly diagnosed with type 1 diabetes and randomly assigned into either control or intervention arm was used. Vitamin D status and Glycohemoglobin (HbA1c) were assessed initially for both the study two arms. Diabetic children of the intervention arm who had vitamin D deficiency and insufficiency were treated with 4000 units of vitamin D3 and calcium (500 mg/day) in oral liquid form. After the study interference (3 months later), HbA1C was measured again for both arms as an indicator for glycemic control. Differences in mean±SD HbA1C and body mass index were assessed before and after the study. Results: The mean of body mass index in intervention arm was 14.77±3.49, while in control arm was 17.84±3.87, with statistically significant deference between two arms P<.001. Furthermore, the mean change in HbA1c levels in intervention arm was 6.78±1.94 compared with 7.03±1.83 in control arm, with no statistically significant deference detected between children of the study two arms P<.460. Conclusion: Vitamin D3 supplement on the clinical base improves glycemic control in pediatrics with type I diabetes mellitus and vitamin D deficiency.