Does vitamin D supplementation benefit patients with type 1 diabetes mellitus who are vitamin D deficient? A study was performed at the Sudan Childhood Diabetes Center from 2019 to 2022.

Objectives: Type 1 diabetes mellitus is a chronic autoimmune disease caused by insufficient production of insulin. Many studies have linked type 1 diabetes mellitus to vitamin D deficiency. We investigated the prevalence of vitamin D deficiency in Sudanese children and adolescents with type 1 diabetes mellitus and assessed the impact of vitamin D deficiency treatment on their glycemic control.

Methods: In 2019-2022, we conducted a quasi-experimental study on 115 children with type 1 diabetes mellitus (1-19 years old) at the Sudan Childhood Diabetes Center. Vitamin D supplements were given orally to deficient patients for 3 months. The concentrations of hemoglobin A1c, fasting blood glucose, insulin dosage, and vitamin D (25-hydroxyvitamin D (25(OH)D)) were measured before and after vitamin D3 administration. One-way ANOVA and paired sample tests were used to evaluate the effect of supplementation.

Results: Only 27% of type 1 diabetes mellitus children were deficient in vitamin D, whereas 31.1% were inadequate and 40.9% were sufficient. The administration of vitamin D supplements slightly improved hemoglobin A1c levels in 67.7% of the patients, but the difference was not significant (mean 10.8 ± 2.1% before, 10.1 ± 2.5% after,  = 0.199). However, there was a significant decrease in the fasting blood glucose level (mean: 174.978.5-136.759.1 ng/ml;  = 0.049). Vitamin D levels were significantly increased after treatment (mean = 49.6 ng/mL; test = -11.6, 95% CI 40.8-(-28.6);  = 0.000). After vitamin D3 supplementation, 25.8% of individuals changed their insulin dosage; however, there was no significant variation in insulin needs.

Conclusions: The prevalence of vitamin D deficiency in children and adolescents with type 1 diabetes mellitus in Sudan is relatively high; incorporating vitamin D supplements in their treatment plan may improve their glycemic control.