Endocrine Abstracts

Background: Animal studies have demonstrated relationship between Vitamin D and glucose homeostasis. There is paucity of evidence examining the relationship between the glycemic control in children with type 1 diabetes mellitus (T1DM) and vitamin D status.

Objective: To determine the effects of vitamin D status on the glycemic control in children and adolescents with T1DM.

Methods: Retrospective data were collected on 348 children and adolescents with TIDM. The serum 25(OH) Vit D concentrations were measured at diagnosis and as part of the annual assessment. Patients were categorized as: Vitamin D deficient (<25 nmol/l), insufficient (25-50 nmol/l) or sufficient (>50 nmol/l). Vitamin D deficiency was treated with 6000 units of cholecalciferol once a day or 20 000 units once a week for 6–8 weeks.

Results: The mean 25(OH) Vit D concentration was 54 nmol/l (±22.9). 52.4% of patients had normal vitamin D concentrations (94% white ethnicity, 2% somali), 39.2% were vitamin D insufficient (87% white ethnicity, 4% somali) and 8.4% were vitamin D deficient (79% white ethnicity, 7% Arabic, 7% mixed background). The mean HbA1C (mmol/mol) for the groups with adequate, insufficient and deficient vitamin D concentrations were 72.36, 72.18 and 69.41 respectively. The mean HbA1C (mmol/mol) prior to treatment with vitamin D supplements was 70.85 (±18.9) and post treatment was 69.85 (±15.95) (P=0.64). There was no significant correlation between vitamin D concentrations and HbA1C (r=0.05, P=0.2).

Conclusions: Low Vitamin D concentrations are fairly prevalent in children with T1DM and much more common in ethnic minority groups. Glycaemic control does not seem to be influenced by the vitamin D status in our retrospective study. Long-term prospective studies are essential.