Adding vitamin D3 to the dipeptidyl peptidase-4 inhibitor saxagliptin has the potential to protect β-cell function in LADA patients: A 1-year pilot study

Diabetes Metab Res Rev. 2020 Jul;36(5):e3298. doi: 10.1002/dmrr.3298. Epub 2020 Feb 20.


Aims: This trial was conducted to explore the protective effect on β-cell function of adding vitamin D3 to DPP-4 inhibitors to treat patients with latent autoimmune diabetes in adults (LADA).

Methods: 60 LADA patients were randomized to group A (n = 21) - conventional therapy with metformin (1-1.7 g/day) and/or insulin treatment; group B (n = 20) - saxagliptin (5 mg/day) plus conventional therapy; and group C (n = 19) - vitamin D3 (2000 IU/day) plus saxagliptin and conventional therapy for 12 months. Fasting and 2-hour postprandial blood samples were collected to measure blood glucose, glycosylated hemoglobin and C-peptide levels at baseline and after 3, 6 and 12 months of treatment.

Results: During the 12 months of follow-up, the levels of fasting C-peptide (FCP), 2-hour postprandial C-peptide (PCP) and the C-peptide index (CPI, serum C-peptide-to-plasma glucose level ratio) were maintained in group C. In contrast to those in group A and group B, FCP levels decreased significantly in group B, and CPI levels declined significantly in group A during the 1-year treatment (P < .05). Additionally, the levels of GADA titers in group C significantly decreased compared with those at baseline (P < .05), but no significant differences in GADA titers levels were detected in group A and group B. No significant differences were found among the three groups in the levels of FCP, PCP, the CPI or GADA titers.

Conclusions: The data suggested that adding 2000 IU/day vitamin D3 to saxagliptin might preserve β-cell function in patients with LADA.

Keywords: GADA; LADA; saxagliptin; vitamin D3; β-cell function.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adamantane / analogs & derivatives*
  • Adamantane / therapeutic use
  • Adolescent
  • Adult
  • Aged
  • Cholecalciferol / administration & dosage*
  • Dipeptides / therapeutic use*
  • Dipeptidyl-Peptidase IV Inhibitors / therapeutic use*
  • Drug Therapy, Combination
  • Female
  • Follow-Up Studies
  • Humans
  • Insulin-Secreting Cells / drug effects*
  • Latent Autoimmune Diabetes in Adults / drug therapy*
  • Latent Autoimmune Diabetes in Adults / etiology
  • Male
  • Middle Aged
  • Prognosis
  • Vitamin D Deficiency / complications*
  • Vitamins / administration & dosage*
  • Young Adult


  • Dipeptides
  • Dipeptidyl-Peptidase IV Inhibitors
  • Vitamins
  • Cholecalciferol
  • saxagliptin
  • Adamantane