Vitamin D Supplementation and Type 2 Diabetes: A Substudy of a Randomised Placebo-controlled Trial in Older People (RECORD Trial, ISRCTN 51647438)

Alison Avenell; Jonathan A. Cook; Graeme S. MacLennan; Gladys C. McPherson


Age Ageing. 2009;38(5):606-609. 

In This Article

Abstract and Introduction


SIR—Studies in animals show that vitamin D deficiency is associated with impaired insulin sensitivity, and that insulin secretion can be increased by vitamin D supplementation.[1] Epidemiological studies in man show associations between low vitamin levels and glucose intolerance.[2]

Pittas et al. systematically reviewed the intervention trial evidence for the role of vitamin D and/or calcium in the prevention of metabolic syndrome and type 2 diabetes mellitus.[2] On the basis of evidence from small intervention trials or post hoc analyses of trials, they concluded that it was difficult to be definite whether or not vitamin D and/or calcium were important in the prevention of type 2 diabetes, and that effects might only be manifest in people who were particularly at risk of type 2 diabetes.

As an adjunct to the RECORD trial,[3,4] a blinded, randomised, placebo-controlled trial of oral vitamin D3 and/or calcium supplementation for the secondary prevention of osteoporotic fractures in older people, we examined whether vitamin D (with or without calcium) was associated with a reduction in self-reported development of diabetes, and starting tablets or insulin for diabetes as indicators of deteriorating glycaemic control.