Vitamin D Plus Other Treatment May Prolong Partial Response in T1D

Additional results from a randomized controlled trial are bolstering the case for vitamin D use, in combination with other treatments, to improve the duration of partial responses for young adults with type 1 diabetes (T1D).

The secondary analysis, published in JAMA Network Open, follow initial results from a phase 3 trial (NCT03046927), which suggest that vitamin D supplementation with ergocalciferol improved insulin sensitivity, subsequently slowing the rise of insulin requirements in patients. Primary analysis findings from the trial were published in 2021. These newest results demonstrate a protective effect of residual β-cell function and partial clinical remission in 36 young patients with a recent diagnosis of T1D.

“Approximately 30% to 50% residual β-cell function may remain at the time of T1D diagnosis, and this may persist for months or years,” explained the researchers. “A prolonged partial remission (PR) phase of T1D leads to improved glycemic control and decreased long-term complications. We previously reported that ergocalciferol significantly decreased circulating tumor necrosis factor-α and temporal trends in both hemoglobin A_1C and insulin dose–adjusted A_1C (IDAA_1C), a marker of PR, compared with placebo.”

The data come from a post hoc analysis of a double-blind, placebo-controlled parallel-group trial of patients randomized to receive ergocalciferol or placebo. Aged between 10 and 21 years, all participants were patients at the University of Massachusetts Medical Center between October 2017 and April 2021. Patients in the study received a high dose of ergocalciferol, receiving 50,000 IU/week for 2 months, followed by the dose biweekly for another 10 months. Two patients each were Asian and Black, 27 were White, and 5 did not report their race.

Compared with placebo, ergocalciferol significantly decreased fasting proinsulin to C-peptide ratio (mean [SE], −0.0009 [0.0008] vs 0.0011 [0.0003]; P = .01). Data also showed that following a similar trend between the 2 groups in the first 3 months, ergocalciferol yielded a mean slow decrease in percent change from baseline in the area under the curve of C-peptide (−28.4 [6.2]; P < .001) compared with placebo (−41.5 [5.9]; P < .001).

“Although this randomized clinical trial was limited by its single-center setting, the results suggest a protective action of ergocalciferol on β cells and possible mechanisms of action to prolong PR. Ergocalciferol’s Δ effect size for β-cell protection (15%) is comparable to that of imatinib, verapamil, and other agents (15%-19.4%). Thus, vitamin D may be combined with other treatments (eg, teplizumab and baricitinib) to prolong PR.”

The relationship between vitamin D and T1D has previously been explored. In 2021, a cross-sectional study found that vitamin D deficiency was associated with an increased risk of coronary disease among patients with T1D who are candidates for pancreas transplantation. Approximately half of the 50 patients attending a medical center in Poland had vitamin D deficiency, which had a significant relationship with coronary artery disease (OR, 4.36; 95% CI, 1.22-5.64; P = .034).

Reference

Nwosu BU, Parajuli S, Sharma R, Lee A. Effects of ergocalciferol on β-cell function in new-onset type 1 diabetes: a secondary analysis of a randomized clinical trial. JAMA Netw Open. 2024;7(3):e241155. doi:10.1001/jamanetworkopen.2024.1155