Nearly 2,000 men aged at least 65 years old took part in the Osteoporotic Fractures in Men study.
Lead author Nicola Napoli, of the University Campus Bio-Medico di Roma, Italy, said: “Although age-adjusted results suggested a trend for a protective effect [of vitamin D], further adjustment for BMI (related to both incident diabetes and 25-[OH]D levels) indicated that this effect was largely explained by the inverse association between vitamin D status and high BMI.”
All participants of the latest study were asked to attend a baseline visit, where they gave fasting morning blood samples.
They also provided their medical history and completed food frequency questionnaires.
Four follow-up visits helped record the data, which included self-reported incident diabetes and medication history.
Researchers assessed the relationship between vitamin D levels and type 2 diabetes and found no association.
The researchers wrote: “While we cannot determine with our observational study if vitamin D supplementation will decrease diabetes risk, our findings suggest that vitamin D status is not associated with diabetes risk in men.”
The association between vitamin D status and the risk of type 2 diabetes has been investigated in previous studies but the results have always been inconsistent.
Findings of another recent study, which was compiled by the Diabetes Research Centre in India, found that more than 70 per cent of participants had deficient and 15 per cent had insufficient vitamin D.
Chief diabetologist Dr Vijay Viswanathan, who was part of the research team, said the findings were significant as studies in the past have identified lack of vitamin D as one of the contributing factors for diabetes.
More research needs to be carried out to determine whether vitamin D supplementation decreases the risk of diabetes.