Background and aims: The relationship between vitamin D deficiency and type I DM is an ongoing area of interest. The study aims to identify the prevalence of vitamin D deficiency in children and adolescents with T1DM and to assess the impact of treatment of vitamin D deficiency on their glycaemic control.
Methods: Retrospective data was collected from 271 children and adolescents with T1DM. The vitamin D deficient (25(OH)D <30 nmol/L) and insufficient (25(OH)D 30-50 nmol/L) patients were treated with 6000 units of cholecalciferol and 400 units of cholecalciferol, once daily for 3 months respectively. HbA1c and 25(OH)D concentrations were measured before and at the end of the vitamin D treatment.
Results: 14.8% from the whole cohort (n = 271) were vitamin D deficient and 31% were insufficient. Among the children included in the final analysis (n = 73), the mean age and plasma 25(OH)D concentration (±SD) were 7.7 years (±4.4) and 32.2 nmol/l (±8.2) respectively. The mean 25(OH)D concentration post-treatment was 65.3 nmol/l (±9.3). The mean HbA1c (±SD) before and after cholecalciferol was 73.5 mmol/mol (±14.9) and 65 mmol/mol (±11.2) respectively (p < 0.001). Children with higher pre-treatment HbA1c had greater reduction in HbA1c (p < 0.001) and those with lower 25(OH)D concentration showed higher reduction in HbA1c (p = 0.004) after treatment.
Conclusions: Low 25(OH)D concentrations are fairly prevalent in children and adolescents with T1DM, treatment of which, can potentially improve the glycaemic control.
Keywords: HbA1C; Type 1 diabetes mellitus; Vitamin D deficiency.