Insufficient intake of vitamin D, long known to play a key role in bone health, may significantly increase a person's risk of stroke, heart disease and even death, a US study says.

Examining 27,686 Utah patients aged 50 or older with no history of cardiovascular disease, the study found those with very low vitamin D levels were 77 per cent more likely to die early than those with normal levels.

They were also found to be 45 per cent more likely to develop coronary artery disease and 78 per cent were more likely to have a stroke, say researchers at the Heart Institute at the Intermountain Medical Centre in Salt Lake City.

Those with very low levels of vitamin D were twice as likely to develop heart failure, said the study presented at a conference organised by the American Heart Association in Orlando, Florida.

"If increasing levels of vitamin D can decrease some risk associated with these cardiovascular diseases, it could have a significant public health impact," said study co-author Dr Heidi May, noting that vitamin D deficiency is easily treatable.

"When you consider that cardiovascular disease is the leading cause of death in America, you understand how this research can help improve the length and quality of people's lives."

Studies have shown that Vitamin D also helps regulate key body functions such as blood pressure, inflammation and glucose control - all related to heart disease - and that deficiency of the vitamin is associated with musculoskeletal disorders.

Brent Muhlestein, another co-author of the study and the director of cardiovascular research at Intermountain, stressed that because the study was only observational, definitive links between vitamin D deficiency and heart disease could not be established.

He called for randomised treatment trials of patients with insufficient levels of the vitamin.

Two-thirds of the Utah population does not get enough vitamin D, the study said.

The researchers chose Utah - home to the Mormon Church - in part because the population consumes low levels of tobacco and alcohol, said Dr Muhlestein, "thus allowing them to focus the study on vitamin D's effects on the cardiovascular system."

- INDEPENDENT