The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial.

Abstract

Background: Vitamin D deficiency is associated with indicators of pre-diabetes including, insulin resistance, β-cell dysfunction and elevated plasma glucose with controversial findings from current trials. This study aims to investigate the long-term effect of vitamin D on glucose metabolism and insulin sensitivity in pre-diabetic and highly vitamin-deficient subjects. Methods: 132 participants were randomized to 30,000 IU vitamin D weekly for 6 months. Participants underwent oral glucose tolerance test (OGTT) at 3-month intervals to determine the change in plasma glucose concentration at 2h after 75g OGTT (2hPCG). Secondary measurements included glycated hemoglobin, fasting plasma glucose and insulin, post-prandial insulin, indices of insulin sensitivity (HOMA-IR, Matsuda Index), β-cell function (HOMA-β, glucose and insulin area under the curve (AUC), disposition and insulinogenic indices), and lipid profile. Results: A total of 57 (vitamin D) and 75 (placebo) subjects completed the study. Mean baseline serum 25(OH) D levels were 17.0 ng/ml and 14.9 ng/ml for placebo and vitamin D group, respectively. No significant differences were observed for 2hPC glucose or insulin sensitivity indices between groups. HOMA-β significantly decreased in the vitamin D group, while area under curve for glucose and insulin showed a significant reduction in β-cell function in both groups. Additionally, HOMA-β was found to be significantly different between control and treatment group and significance persisted after adjusting for confounding factors. Conclusion: Vitamin D supplementation in a pre-diabetic and severely vitamin-deficient population had no effect on glucose tolerance or insulin sensitivity. The observed reduction in β-cell function in both placebo and vitamin D groups could be attributed to factors other than supplementation. Trial registration: The trial was registered at www.clinicaltrials.gov with number: NCT02098980.

A Randomized, Placebo-Controlled Crossover Study to Evaluate Postprandial Glucometabolic Effects of Mulberry Leaf Extract, Vitamin D, Chromium, and Fiber in People with Type 2 Diabetes

“…An interesting concept with this blend, and which represents a study novelty, is that in contrast to many previous studies conducted with MLE, we combined the MLE with three other bioactive ingredients, i.e., vitamin D 3 , chromium, and dietary fiber, with the rationale that these additional ingredients of the blend would represent a reasonable source of these (micro)nutrients, given that many people across the globe are on the lower side of adequate daily nutrient intake, which is in particular true for people with T2D [58][59][60]. In addition, these ingredients have been implied to offer glycemic benefits [36,37,[39][40][41][42][43]61] which may offer additivity with the MLE, although some of the effects of particular blend ingredients for glucose benefits have been debated [62][63][64], in particular low-dose vitamin D 3 . Thus, this mix can provide added nutritional value to people with T2D, thus supporting long-term adherence, which is also supported by recent guidelines [65] that now advocate a ''patient-centered approach,'' where, for many people with T2D, nutritional supplements, if supported by evidence, tend to be desired over adding another medication.…”

Nanocarriers System for Vitamin D as Nutraceutical in Type 2 Diabetes: A Review

“…The form of Vitamin D used for fortification is Vitamin D2 or Vitamin D3 [29]. Fortification of the active form of Vitamin D (Vitamin D3) is considered efficient in the supplying requirement of Vitamin D. Addition of Vitamin D3 to food has shown an improvement in blood glucose and insulin status in diabetes mellitus [30]. Vitamin D deficiency has been associated with decreasing insulin release, increasing insulin resistance, and type 2 diabetes mellitus.…”

Supplementation of Vitamin D in Diabetic Patients

“…Diabetes mellitus [DM] is one of the most common disease around the world, and their occurrence continues cardiovascular disease, hypertension, cancer risk and diabetes mellitus. In particular, higher prevalence of low serum vitamin D [25-(OH)D] levels was observed in patients with type 2 diabetes whereas higher levels of vitamin D [25-(OH)D] were associated with lower risk of type 2 diabetes (T2DM) [6,7].…”