eng Science and Education Publishing American Journal of Nursing Research 2378-5586 2019-05-25 7 4 534 541 10.12691/ajnr-7-4-15 AJNR20197415 article Rabab El-Sayed Hassan El-Sayed biboelsayed@gmail.com 1 Samar El Hoseiny Abd El Raaouf 2 Wafaa Laimon 3 Pediatric Nursing Department, Faculty of Nursing, Mansoura University, Egypt Community Health Nursing Department, Faculty of Nursing, Mansoura University, Egypt Pediatric Endocrinology and diabetes Unit, Pediatric Department, Faculty of Medicine, Mansoura University, Egypt 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. http://pubs.sciepub.com/ajnr/7/4/15/ajnr-7-4-15.pdf Vitamin D Glycemic control Children Type 1 diabetes mellitus Glycohemoglobin (HbA1c)