Background: Several studies have suggested that vitamin D supplementation in early childhood is successful in decreasing the risk of type 1 diabetes (T1D) through a complex immunomodulatory role. However, Intervening in disease once clinical symptoms have appeared and autoreactive immune responses are active might be more challenging. Controlled trials with vitamin D supplementation in recent-onset T1D have shown mixed results.
Objective and hypotheses: The aim of this pilot trial was to investigate whether supplementation with cholecalciferol in subjects with recent-onset T1D is able to protect residual β-cell function (C-peptide) and to improve metabolic control (HbA1c, insulin requirement).
Method: Twenty-eight subjects with recent-onset T1D and basal C-peptide >0.2 nmol/l were randomized in a prospective non-blinded controlled trial to supplementation with oral cholecalciferol 1332 IU/day (n=14) or standard therapy (n=14). C-peptide, HbA1c and 25-hydroxyvitamin D (25HOD) levels were measured at baseline and after a mean period of 13.4 months (S.D.=2.5). Insulin requirements were evaluated by total daily dose (U/kg per day). SPSS 20 was used for data analysis.
Results: Mean age at T1D diagnosis was 7.9 years (S.D.=3.9). At baseline, the majority of patients had inadequate 25OHD levels: insufficiency (2129 ng/ml) (48,5%) and deficiency (≤20 ng/ml) (12.1%). On the follow-up evaluation, the cholecalciferol supplementation group had significantly higher 25OHD (mean 59.72 vs 37.67 ng/ml, P=0.05) and C-peptide levels (mean 0.32 vs 0.062 nmol/l, P=0.007) when compared to the standard therapy group. The cholecalciferol supplementation group needed lower insulin daily dose (0.58 vs 0.66 U/kg per day) and had lower HbA1c (7.54 vs 7.71%) than the control group, on the follow up evaluation, even though statistical significance was not reached.
Conclusions: This pilot study suggests that cholecalciferol supplementation in recent-onset T1D might prolong endogenous insulin production, and possibly improve glycemic control with lower insulin requirements.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology