Vitamin supplements taken by millions of people can increase the risk of heart disease, a large study suggests .

New research has found links between certain types of daily pills combining calcium and vitamin D and an increased risk of stroke.

US scientists believe the combination may be responsible for atherosclerosis, a disease whereby plaque builds up in the arteries.

Such pills are commonly marketed as necessary to preserve bone strength and aimed at middle-aged and elderly people, whose risk of stroke is already higher.

Overall, it is estimated that around 45 per cent of UK adults take some form of vitamin supplements every day, supporting an industry worth roughly £430 million a year.

Published in the Annals of Internal Medicine, the new data forms part of a wider set of results suggesting that few nutritional supplements protect against cardiovascular disease or death .

Based on a review of 277 randomised controlled trials comprising nearly one million people, the study also questioned the effectiveness of a Mediterranean-style diet for improving resilience against heart disease.

Dr Safi Khan, who led the research at West Virginia University, said: "A combination of calcium and vitamin D was associated with a higher risk of stroke."