Vitamin D Supplementation for Prevention of Type 2 Diabetes Mellitus: To D or Not to D?

Abstract

Context Over the last decade, vitamin D has emerged as a risk determinant for type 2 diabetes and vitamin D supplementation has been hypothesized as a potential intervention to lower diabetes risk. Recently, several trials have reported on the effect of vitamin D supplementation on diabetes prevention in people with prediabetes. Evidence Acquisition A comprehensive literature review was performed using PubMed, Embase, and ClinicalTrials.gov to identify: 1) recent meta-analyses of longitudinal observational studies that report on the association between blood 25(OH)D level and incident diabetes and 2) clinical trials of adults with prediabetes that have reported on the effect of vitamin D supplementation on incident diabetes. Evidence Synthesis Longitudinal observational studies report highly consistent associations between higher blood 25(OH)D levels and lower risk of incident diabetes in diverse populations, including populations with prediabetes. Trials in persons with prediabetes show risk reduction in new-onset diabetes with vitamin D supplementation. In the three large trials that were specifically designed and conducted for prevention of diabetes, vitamin D supplementation when compared with placebo, reduced risk of diabetes by 10 to 13% in persons with prediabetes not selected for vitamin D deficiency. Conclusions Results from recent trials are congruent with a large body of evidence from observational studies indicating that vitamin D has a role in modulating diabetes risk. Participant-level meta-analysis of the three largest trials should provide a more refined estimate of risk reduction and identify patient populations likely to benefit the most.

Prevalence of people at risk of developing type 2 diabetes mellitus and the involvement of community pharmacies in a national screening campaign: a pioneer action in Brazil

“…This relationship being more pronounced in patients with inflammatory diseases, such as diabetes, compared to patients with non-inflammatory diseases [43]. In addition, it has been speculated that vitamin D supplementation may contribute to reducing the risk of developing diabetes in patients at risk of developing the disease [44]. Similar to the results reported by Passos et al (2005), it was verified a positive relationship between physical inactivity and high CBG [45].…”

Vitamin D and Cardiovascular Disease: An Updated Narrative Review

“…When summarizing data on vitamin D and CVD in this paper, we have to acknowledge that we did not discuss in detail the evidence for vitamin D, and common as well as emerging cardiovascular risk factors such as diabetes mellitus or inflammation, that may be relevant in mediating a potential link between vitamin D and CVD [ 105 , 106 , 107 , 108 ]. We are well aware that there is accumulating evidence on a role of vitamin D in, e.g., inflammation, but this did obviously not translate into an improved cardiovascular outcome in vitamin D RCTs, although immunomodulatory effects of vitamin D may well be relevant in the context of autoimmune or infectious diseases [ 107 , 108 ].…”

Effect of Vitamin D3 Supplementation Combined with Exercise Training on Glycemic Control and Bone Health in Patients with Type 2 Diabetes: A Randomized, Placebo-Controlled Trial

“…In addition to the traditional role in maintaining bone health, higher serum 25(OH)D levels have been found to be associated with a low risk of developing type 2 diabetes [7][8][9][10] . However, to date, the ndings in previous studies are inconsistent [12][13][14][15][16][17] , and these studies have mainly been conducted in non-Asian populations.…”

“…In addition, altered vitamin D homeostasis may play a role in the development of insulin resistance (IR) and type 2 diabetes 6 , and low 25(OH)D levels are associated with a high prevalence of type 2 diabetes 7,8 . Therefore, vitamin D supplementation has been proposed as a potential intervention to lower the incidence of type 2 diabetes 9,10 .…”

“…Zhang et al recently showed that in China, 50% of type 2 diabetes patients were vitamin D de cient, which could further deteriorate glucose tolerance status 11 . However, to date, studies on the role of vitamin D supplementation in IR in type 2 diabetes patients have been mainly conducted in non-Asian countries, and the ndings are inconsistent [12][13][14][15][16][17] , partly because of marked differences in study duration, participant population, and dosing regimen 9,10 . Furthermore, the independent effect of vitamin D on glycemic control is possibly limited in type 2 diabetes patients 18 .…”