Effect of Vitamin D Fortified Cheese on Oral Glucose Tolerance in Individuals Exhibiting Marginal Vitamin D Status and an Increased Risk for Developing Type 2 Diabetes: A Double‐Blind, Randomized Placebo‐Controlled Clinical Trial

Epidemiological data suggest that vitamin D may play a role in glucose metabolism and homeostasis, and that it maybe particularly important for individuals at an increased risk for developing type 2 diabetes mellitus (T2DM). Objective We conducted a double‐blind, randomized, placebo‐controlled trial to examine the effects of 28,000 IU of vitamin D3 given in cheese once per week versus placebo on the 2hr oral glucose tolerance test (OGTT) and measures of insulin sensitivity, secretion and β‐cell function. Study Design Potential participants were identified as being at an increased risk for developing diabetes using the Finnish Diabetes Risk Score (FINDRISC) questionnaire. Participants who were vitamin D deficient (serum 25‐hydroxy vitamin‐D [25(OH)D] ≤65nmol/L) and who had elevated glycated hemoglobin (HbA1c) between 5.4 and 6.4% and/or fasting glucose between 5.6 and 6.9 mmol/L were randomized to receive 28,000 IU of vitamin D3 or placebo (20 IU) once weekly for a period of 24 weeks. The primary outcome of interest was the difference in plasma glucose 2hr after an OGTT between baseline and 24 wks. Secondary outcomes include fasting glucose, fasting and postprandial insulin and indices of insulin sensitivity (Matsuda Index), secretion (insulinogenic index), β–cell function (ISSI‐2) and long‐term glycemic status (HbA1c). Data were analyzed by intention‐to‐treat. Results Seventy‐one participants (mean age 47.4) were randomized and sixty‐three completed the trial. Supplementation produced a significant increase in serum 25(OH)D in the vitamin D group (n= 35) versus placebo (n=36) (103.6±36.5 vs. 46.4±18.9 nmol/ L, p <0.0001). After 24 wks of supplementation 74% of participants in the vitamin D group achieved 25(OH)D levels ≥75nmol/Lvs6% in the placebo group. Supplementation produced no significant improvements in fasting (p=0.89) and glucose 2hr after the OGTT (p= 0.88), fasting (p= 0.28) and postprandial (p= 0.77) insulin, HbA1c (p=0.34), HOMA‐IR (p= 0.32), Matsuda Index (p=0.72), and ISS1‐2 (p=0.86). Conclusion Weekly doses of 28,0000 IU of vitamin D3 for 24 wks in a group of multi‐ethnic, vitaminD–deficient individuals identified as being at high risk for developing T2DMdid not improve oral glucose tolerance, insulinsensitivity, β–cell function or HbA1c. Support or Funding Information Research funded by the Dairy Farmers of Canada and the Public Health Agency of Canada.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.