Vitamin D has been linked to heart health in a new study from researchers at the University of South Australia (UniSA).

Thestudy, published inEuropean Heart Journal, uses a genetic approach that allowed the team to assess how increasing vitamin D levels can affect CVD risk based on how high participants’ actual vitamin D levels were. It used information from up to 267,980 individuals, which allowed the team to provide robust statistical evidence for the link between vitamin D deficiency and CVD, a press release states.

Why do it this way? UniSA's Professor Elina Hyppönen, chief investigator on the study, explained in the press release: “It is not ethical to recruit people with vitamin D deficiency to a randomized controlled trial and to leave them without treatment for long periods. It is exactly this type of difficult setting which demonstrates the power of our genetic approach, given we can show how improving concentrations affects the risk in those most in need, without exposing participants to any harm.”

The research found that participants with the lowest concentrations of plasma vitamin D had more than double the risk of heart disease compared to those with sufficient concentrations.

"Severe deficiency is relatively rare, but in settings where this does occur it is very important to be proactive and avoid negative effects on the heart,” said Prof. Hyppönen. “For example, deficiency can be a problem for people living in residential care who may have limited exposure to sun. We can also get vitamin D from food, including oily fish, eggs and fortified foods and drinks. This said, food is unfortunately a relatively poor source of vitamin D, and even an otherwise healthy diet does not typically contain enough.” Supplements, she says, can help fill that gap.

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Looking at the disease burden for CVD, the press release notes that low levels of vitamin D are seen in an estimated 23% of people in Australia, 24% of people in the U.S., and 37% of people in Canada.

“Understanding the connection between low levels of vitamin D and CVD is especially important, given the global prevalence of this deadly condition,” Prof. Hyppönen concluded. “Our results are exciting as they suggest that if we can raise levels of vitamin D within norms, we should also affect rates of CVD. In our study population, by increasing vitamin D-deficient individuals to levels of at least 50 nmol/L, we estimate that 4.4% of all CVD cases could have been prevented."