Previous studies have indicated that it might offer a variety of other health benefits, including protecting against cancer, peripheral artery disease and tuberculosis.

Now, a team at Graz University in Austria has found that the “sunshine vitamin” helps the body absorb calcium and facilitates growth of bones, which in turn do have a positive impact on death rates.

“This is the first association study that shows vitamin D affects mortality regardless of the (primary) reason for death,” ‘The Daily Telegraph’ quoted lead researcher Harald Dobnig as saying.

Vitamin D is also found in milk and in fatty fish like salmon, but many people do not get enough of it. A lack of it can lead to rickets in children and osteoporosis in adults.

In their study, the researchers analysed more than 3,200 people with an average age of 62 who were scheduled for a heart examination between 1997 and 2000. They were also followed up for eight years.

During this period, the team found that the quarter of volunteers with the lowest levels of vitamin D in their blood were more likely to have died.

The risk was doubled for people with between five to ten nanograms per millilitre of vitamin D in their blood, even when factors like heart disease, exercise and other conditions were taken into account, Dr Dobnig said.

He added: “Most doctors believe people should have between 20 to 30 nanograms per millilitre of the vitamin in their blood.”