Vitamin D may help prevent the development of type 2 diabetes

Individuals with increased blood sugar levels and with large amounts of vitamin D in their plasma are up to 25 percent less likely to develop type 2 diabetes, says a new US study.

In the randomized controlled trial, 2,039 people with higher-than-normal blood sugar levels, (‘prediabetes’) were assessed for their plasma vitamin D (25OHD) levels, measured at yearly intervals, and the incidence of type 2 diabetes recorded for a mean of 3.2 years (1). The participants were allocated to groups receiving an intensive lifestyle modification or placebo. The study results showed that, after adjustment for age, gender and several health conditions and lifestyle factors, participants with the highest vitamin D blood concentrations (median 25OHD 30.1 ng/mL) had a significantly reduced risk for developing diabetes compared to participants with the lowest plasma levels (median 25OHD 12.8 ng/mL). This preventive effect was also visible in the group receiving lifestyle interventions known to decrease diabetes risk.

The researchers concluded that vitamin D may help prevent those at high risk for diabetes from developing the disease, giving doctors and patients a potential tool against the condition. Vitamin D may help the body produce more of the hormone insulin or may increase the body’s sensitivity to insulin.

More than 220 million people worldwide have diabetes, of whom about 90 percent have the type 2 form of the condition, according to the World Health Organization. People who are obese are most at risk of developing type 2 diabetes, in which either the body does not produce enough insulin to convert blood sugar to energy, or the cells ignore the insulin. Left untreated, type 2 diabetes can lead to heart attack, stroke and blindness.

1. Pittas A. G. et al. Vitamin D status and progression to diabetes in patients at risk for diabetes: an ancillary analysis in the diabetes prevention program randomized controlled trial. Oral presentation at the American Diabetes Association’s annual meeting. June 2011.