In adults with type-2 diabetes, a dose of vitamin D in winter was associated with improved vascular function, researchers from the University of Dundee will tell delegates at the British Cardiovascular Society annual scientific conference in Glasgow this week.

The study took place in the winter of 2005/6 in Tayside, Scotland. Eighty-seven people with an average age of 64, with type-2 diabetes, were randomly assigned to receive a single 100,000 U dose of vitamin D in the form of ergocalciferol or placebo.

At baseline and eight-week follow-up, the participants were assessed for flow-mediated vasodilation (FMD), office and 24-hour BP, and fasting blood sugar and vitamin D levels.

This showed that 49 per cent of the patients had vitamin D levels lower than 50nmol/l. 

Patients who received ergocalciferol had a 22.9nmol/l increase in serum 25-hydroxyvitamin D, compared with 7.6nmol/l in the placebo group.

Patients who were given the vitamin D supplement had an improvement in FMD of 2.35 per cent, compared with 0.06 per cent in those given placebo.

Researchers said vitamin D could reduce the rate of vascular events in type-2 diabetes.

British Cardiovascular Society Annual Scientific Conference