The belief that Vitamin D deficiency caused by lack of sunshine provokes heart disease and winter deaths has been challenged by researchers in Scotland.
Vitamin D levels, says the research team hailing from the University of Dundee, are not a key factor in cardiovascular disease and winter deaths.
In 1981 the Cardiovascular Epidemiology Unit in Ninewells Hospital in Dundee was founded to uncover what causes the excess of heart disease in Scotland, and the ongoing Scottish Heart Health Study — of which the current study is a chapter — began.
The research team set out to examine a link between vitamin D and increased winter cardiovascular events and blood samples were taken from thousands of healthy citizens at the time who agreed that their medical records could be followed.
The samples were recently tested for vitamin D in an entirely new project in Germany and the team shared the results with the Scottish Heart Health study.
Analysis indicated no seasonal variation in overall incidence of cardiovascular events although such was not the case when it came to deaths from heart disease and other causes.
They were more frequent during winter, when vitamin D levels were at their lowest, although peak winter death rates occurred several weeks after the dip and were considered too late to be the cause.
Individuals with low vitamin D levels had higher rates of cardiovascular disease, but vitamin D deficiency was also associated with lifestyle, according to the study; data adjusted for that and other risk factors suggests vitamin D plays a negligible role.
In addition to standard risk factors, the team weighed social isolation and family history into the equation and found vitamin D made no significant contribution to cardiac disease.
“This is a major study, in a population with two-to-one seasonal changes in vitamin D, and low levels overall,” says emeritus professor Tunstal-Pedoe who leads the Scottish Heart Health Study. “If vitamin D deficiency were a major cause of heart disease and death, we would have expected it to show up. But it did not. So our results seriously challenge its alleged role.”
The study “Prime mover or fellow traveller: 25-hydroxy vitamin D’s seasonal variation, cardiovascular 5 disease and death in the Scottish Heart Health Extended Cohort (SHHEC)” was published in the International Journal of Epidemiology.
- Health Care Industry
- Vitamin D deficiency
- heart disease
- Vitamin D levels