Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Sep;65(9):1005-15.
doi: 10.1038/ejcn.2011.118. Epub 2011 Jul 6.

Vitamin D and type 2 diabetes: a systematic review

J Mitri  1 , M D Muraru, A G Pittas
Affiliations

Vitamin D and type 2 diabetes: a systematic review

J Mitri et al. Eur J Clin Nutr. 2011 Sep.

Abstract

Background/objectives: Vitamin D may modify the risk of type 2 diabetes mellitus. The aim of this review was to examine the association between vitamin D status and incident type 2 diabetes, and the effect of vitamin D supplementation on glycemic outcomes.

Methods: We performed a systematic review of English-language studies using MEDLINE through February 2011. Longitudinal cohort studies reporting associations between vitamin D status and incident type 2 diabetes, and randomized controlled trials (RCTs) of vitamin D supplementation, were included. Study characteristics and results were extracted, and study quality was assessed.

Results: A total of 8 observational cohort studies and 11 RCTs were included. In meta-analyses of observational studies, vitamin D intake>500 international units (IU)/day decreased the risk of type 2 diabetes by 13% compared with vitamin D intake<200 IU/day. Individuals with the highest vitamin D status (>25 ng/ml) had a 43% lower risk of developing type 2 diabetes (95% confidence interval 24, 57%) compared with those in the lowest group (<14 ng/ml). In post hoc analyses from eight trials among participants with normal glucose tolerance at baseline and in three small underpowered (n=32-62) trials of patients with established type 2 diabetes, there was no effect of vitamin D supplementation on glycemic outcomes. In two trials among patients with baseline glucose intolerance, vitamin D supplementation improved insulin resistance.

Conclusions: Vitamin D may play a role in type 2 diabetes; however, to better define the role of vitamin D in the development and progression of type 2 diabetes, high-quality observational studies and RCTs that measure blood 25-hydroxyvitamin D concentration and clinically relevant glycemic outcomes are needed.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Meta-analysis of the association between self-reported vitamin D intake and incident type 2 diabetes.
Figure 2
Figure 2
Meta-analysis of the association between baseline blood 25(OH)D concentration and incident type 2 diabetes.
See this image and copyright information in PMC

References

    1. Anderson JL, May HT, Horne BD, Bair TL, Hall NL, Carlquist JF, et al. Relation of vitamin D deficiency to cardiovascular risk factors, disease status, and incident events in a general healthcare population. Am J Cardiol. 2010;106:963–968. - PubMed
    1. Avenell A, Cook JA, MacLennan GS, McPherson GC. Vitamin D supplementation and type 2 diabetes: a substudy of a randomised placebo-controlled trial in older people (RECORD trial, ISRCTN 51647438) Age Ageing. 2009;2009;38:606–609. - PubMed
    1. Campbell IT, Jarrett RJ, Keen H. Diurnal and seasonal variation in oral glucose tolerance: studies in the Antarctic. Diabetologia. 1975;1975;11:139–145. - PubMed
    1. Dawson-Hughes B, Harris SS. High-dose vitamin D supplementation: too much of a good thing? Jama. 2010;2010;303:1861–1862. - PubMed
    1. de Boer IH, Tinker LF, Connelly S, Curb JD, Howard BV, Kestenbaum B, et al. Calcium plus vitamin D supplementation and the risk of incident diabetes in the Women’s Health Initiative. Diabetes Care. 2008;2008;31:701–707. - PMC - PubMed

Publication types

MeSH terms