Immunointervention With 1,25-dihydroxy-vitamin D3 in New-onset Type 1 Diabetes

This is a randomized, two-arm, placebo-controlled phase-2 trial to determine whether the daily intake of 1,25-dihydroxy-vitamin D3 [1,25(OH)2D3], improves beta cell function in patients with recently diagnosed type 1 diabetes. The treatment consists of the daily oral administration of 0.25 µg 1,25(OH)2D3 or placebo for 9 months and an equal follow-up time without supplementation. Fasting, peak and AUC C-peptide concentrations during a 2-hour mixed meal tolerance test are measured at the beginning of the study, as well as at the end of the treatment and the follow-up period in month 9 and 18. The null hypothesis is that there is no difference between 1,25(OH)2D3 treated subjects and the placebo group in the AUC C-peptide at month 18.