A person's risk of developing type 2 diabetes does not appear to be affected by the amount of vitamin D in their body, as suggested by previous studies, new genetic research reveals.

Earlier studies had suggested that people with a higher concentration of vitamin D in their bodies were less likely to develop type 2 diabetes. This lead some to speculate that vitamin D insufficiency may increase the risk of the condition.

Scientists at the University of Cambridge in the UK decided to investigate this further. They assessed the link between the risk of diabetes and vitamin D by examining the genes that control blood levels of the vitamin.

They found no link between different gene variants that control the body's vitamin D levels and the risk of developing diabetes.

The scientists pointed out that the earlier studies had been observational, therefore they could not directly investigate the cause and effect relationship between vitamin D and type 2 diabetes.

"Our findings suggest that interventions to reduce the risk of type 2 diabetes by increasing concentrations of vitamin D are not currently justified.

"Observational studies that show a strong and consistent higher risk of type 2 diabetes with lower levels of vitamin D may do so because they have thus far not been able to adequately control for distorting or confounding factors, such as physical activity levels, that may be related both to vitamin D levels and to the risk of type 2 diabetes," commented Dr Nita Forouhi of the University of Cambridge.

She said that further research is needed to allow for a ‘precise measurement of important factors that may affect vitamin D and disease relationships'.

"Until then, we need to be cautious about vitamin D's potential role in the prevention of type 2 diabetes and stick to things that are proven to work - diet and exercise," she added.

Vitamin D is known to be necessary for bone health but research has suggested that its benefits may extend past this. Sunshine is the primary source of the vitamin, with the body producing it as a result of the action of sunlight on the skin. It can also be found in supplements and some foods, such as oily fish and fortified milk and cereal.

Details of these findings are published in the journal, The Lancet Diabetes & Endocrinology.