Vitamin D in Adolescents and Young Adults With Type 1 Diabetes

Investigators examined a potential link between ergocalciferol (vitamin D2) and residual B-cell function and partial remission in adolescents and young adults with newly diagnosed type 1 diabetes.

Among adolescents and young adults newly diagnosed with type 1 diabetes (T1D), ergocalciferol (Vitamin D2) was found to significantly reduce serum tumor necrosis factor (TNF)-a concentration, according to results of a study published in the Journal of the Endocrine Society.

Beginning in 2016, patients (N=36) newly diagnosed (<3 months) with T1D were recruited for this investigator-initiated, single-center, randomized, double-blind, parallel trial at the University of Massachusetts Medical School. Patients were randomized to receive 50,000 IU ergocalciferol (n=18) or placebo (n=18) every week for 2 months followed by a bimonthly dose for 10 months. At 12 months, alterations to serum biomarkers were assessed.

The treatment and control cohorts were aged mean 13.25 for ergocalciferol (standard deviation [SD], 2.76) and 14.28 (SD, 2.86) years for the placebo group.  In the ergocalciferol group, 55.6% were boys or men, compared with 77.9% in the placebo group. Also in the ergocalciferol and placebo groups,  85.7% and 88.2% were White, body mass index (BMI) was 22.03 (SD, 5.41) and 22.01 (SD, 4.15) kg/m2, and glycated hemoglobin (HbA1C) was 7.62% (SD, 1.35%) and 7.47% (SD, 1.69%), respectively.

At 6 and 9 months, 25-hydroxyvitamin D  [(25OH)D)] concentrations were significantly elevated among ergocalciferol recipients (P=.01 and P =.02) than placebo.

At 12 months, no significant difference was seen in systolic and diastolic blood pressure, BMI, waist circumference, fasting C-peptide, stimulated C-peptide, fasting blood glucose, or total daily dose of insulin were observed.

Among all study participants, HbA1C increased significantly (P <.0001) but no group effect was observed (P =.09), however, HbA1C increased more quickly among the placebo group every 3 months (mean rate change, 0.46% vs 0.14%; P =.044).

Insulin-dose adjusted A1C (IDAA1C) increased among all study participants (P <.0001). At 3 months, IDAA1C was lower among the placebo cohort (P =.05). After 3 months, IDAA1C increased more rapidly among the placebo cohort every 3 months than in the ergocalciferol cohort (mean rate change, 0.77 vs 0.30; P =.015).

The rate change of TNF-a every 3 months was higher among the placebo recipients (mean rate change, 0.03 vs -0.01; P =.20). By month 12, the TNF-a concentration was significantly lower among ergocalciferol recipients (mean, 1.12±0.1 vs 1.32±0.3 pg/mL; P =.03).

There was no evidence of hypercalcemia, hypercalciuria, or vitamin D toxicity observed during the study. Diabetic ketoacidosis (n=1) and confirmed COVID-19 (n=1) occurred among the placebo group.

This study was limited by its single-center design and participant study visits were suspended between March 2020 and June 2020 due to the COVID-19 pandemic.

“Adjunctive ergocalciferol supplementation significantly reduced serum TNF-α concentration and significantly blunted the rates of increase in both A1c and IDAA1c , suggesting a protection of residual B-cell function and partial remission in youth with newly-diagnosed T1D,” the researchers concluded. “This suggests that ergocalciferol slowed the rise in insulin requirements by improving insulin sensitivity in youth with newly-diagnosed T1D. Larger studies are needed to quantify the impact of vitamin D on insulin sensitivity in youth with T1D.”


Nwosu BU, Parajuli S, Jasmin G, et al. Ergocalciferol in new-onset type 1 diabetes: a randomized controlled trial. J Endocr Soc. Published online November 26, 2021. doi: 10.1210/jendso/bvab179