Vitamin D supplements could be as effective as prescription medicine at reducing high blood pressure, a conference will hear.

The once a day tablets, available from chemists, produced reductions in high blood pressure 'as powerful' as medicines, a Danish study has found.

A group to 112 patients with high blood pressure were given the supplements for 20 weeks and showed significant improvements in their condition.

The findings were presented at the European Society of Hypertension conference in London.

High blood pressure affects 16m adults in Britain and accounts for 62,000 deaths mostly by causing strokes and heart attacks.

Vitamin D can be obtained from food but most is made in the skin from sunlight, however in Britain this can only happen in stronger light in the summer months.

They were treated at Holstebro Hospital in Denmark which is on a similar latitude to Glasgow and Moscow.

Of the 112 participants 92 were found to have low levels of vitamin D at the start of the study.

The researchers found that those patients taking the vitamin D supplement showed a significant reduction in central systolic blood pressure, measured at the aorta, near the heart, when compared to the placebo group.

The systolic blood pressure, the first number expressed in a blood pressure reading, was reduced by 6.8 mmHg, diastolic blood pressure was reduced by 1.7mmHg.

Study leader Dr Thomas Larsen said: “Probably the majority of Europeans have vitamin D deficiency, and many of these will also have high blood pressure.

"What our results suggest is that hypertensive patients can benefit from vitamin D supplementation if they have vitamin D insufficiency.

"Vitamin D would not be a cure for hypertension in these patients, but it may help, especially in the winter months. However, it is important to stress, that this was a small study, and that larger studies are needed to provide solid evidence."

Professor Anna Dominiczak, vice-president of the European Society of Hypertension and University of Glasgow, said: "The effects of vitamin D supplements was as powerful as tablets in trials.

“These results show a significant reduction in Central Systolic Blood Pressure in patients taking the vitamin D supplement for 20 weeks, when compared to the placebo group.

"This is an initial study, so it needs to be confirmed, but it is potentially interesting as part of an overall strategy for managing hypertension in patients with low levels of vitamin D."