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What do we know about the relationship between vitamin D levels and cardiovascular risk? Image credit: Sam Burton/Stocksy.
  • Vitamin D is essential for good health, and the precise impact it has on different aspects of health and the mechanisms underpinning this are the focus of much research.
  • Previous studies have linked this nutrient to improved cardiovascular health.
  • Researchers from the Swiss Nutrition and Health Foundation have found a link between vitamin D supplementation and a lower risk for cardiovascular events.
  • No association was found between taking vitamin D supplements and cardiovascular disease risk or overall death risk.

Vitamin D is one of the essential nutrients your body needs to stay healthy. Not only does it help ensure the bones stay strong, but it also supports the body’s immune system and helps regulate cellular functions throughout the body, including those of brain cells.

Over the past few years, there have been a number of studies linking vitamin D to other potential health benefits, including improved cardiovascular health.

Now, scientists from the Swiss Nutrition and Health Foundation in Epalinges, Switzerland, are adding to this research with a new study showing a link between lower vitamin D levels and a higher risk of cardiovascular events.

However, there was no association between having normal vitamin D levels and lower cardiovascular disease or overall death risk. The same results were found when removing participants who took vitamin D supplementation.

This study was recently published in the journal Nutrients.

According to Dr. Cheng-Han Chen, an interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA — who was not involved in this study — doctors believe that vitamin D influences cardiovascular health in a complex way through its effect on many cardiovascular risk factors.

“For instance, some studies have shown that very low vitamin D levels will increase someone’s blood pressure, which is a risk factor,” he explained to Medical News Today.

Other studies [found that] a low vitamin D level could impact glucose resistance, which is a risk factor for diabetes. And other studies have shown that low vitamin D levels could increase levels of bad cholesterol, which again is a risk factor [for cardiovascular problems],” he noted.

Additionally, past studies show a link between vitamin D deficiency and obesity, which is also a cardiovascular disease risk factor.

“I think this research adds to good general advice that everybody should have their vitamin D levels checked regularly by their primary care physician,” Dr. Chen said. “And for those found to have very low levels, we would recommend that they get vitamin D supplementation.”

Although there has been much research conducted on vitamin D and cardiovascular disease, the results are inconsistent, said Dr. Pollyanna Patriota, a researcher at the Swiss Nutrition and Health Foundation in Epalinges, Switzerland, and the first author of this study.

“The role of vitamin D in cardiovascular disease is still debated and there is no strong evidence that vitamin D supplementation can improve heart health,” she told MN. “Likewise, whether supplementation of patients at high cardiovascular disease risk and presenting with vitamin D insufficiency is beneficial with regards to cardiovascular disease outcomes deserves further investigation.”

“Cardiovascular disease remains a major cause of mortality worldwide, and despite advances in therapeutic approaches, efficient prevention strategies are required in which diet is definitely an important component,” Dr. Patriota added.

She said she and her colleagues decided to study the effect of vitamin D on cardiovascular health because previous studies assessing this association had several limitations, such as participant diversity and a short follow-up period.

“Therefore, we decided to study the association between vitamin D levels and cardiovascular events, cardiovascular mortality, and overall mortality, in an apparently healthy, population-based sample living in Lausanne, Switzerland,” she added.

For this study, Dr. Patriota and her team recruited almost 5,700 participants — of which slightly more were women — from Lausanne, Switzerland. All participants had vitamin D levels that were categorized as either normal, insufficient, or deficient. Scientists assessed the participants’ health over an average of about 14 years.

Upon analysis, researchers found a correlation between better vitamin D levels and a lower risk for cardiovascular disease.

However, the study did not find a link between lowered vitamin D levels and a heightened risk for deaths caused by either cardiovascular disease or overall causes.

“This is a population-based study, in a very specific population, i.e. a community-dwelling, apparently healthy population,” Dr. Patriota said. “We suggest that larger studies should be developed to clarify the impact of vitamin D supplementation on cardiovascular health.”

The body is able to make vitamin D when the skin is exposed to the sun. However, that sometimes does not generate enough vitamin D, making supplementation necessary.

A person can increase their vitamin D by taking a dietary supplement and by eating foods rich in vitamin D, such as egg yolks, beef liver, certain mushrooms, fatty fishes — like salmon, tuna, and mackerel — and fish liver oil.

There are also a variety of foods on the market in many countries that are fortified with vitamin D, including milk, cheese, plant-based milk alternatives, orange juice, yogurt, and cereals.

Most times, if a person is vitamin D deficient they will not have any symptoms. This is why it is important to have vitamin D levels checked regularly by a physician.

However, very low vitamin D levels can sometimes result in certain symptoms, including:

In addition to cardiovascular disease, previous research shows that a low vitamin D level may increase a person’s risk for infections, autoimmune diseases, neurological diseases, and certain types of cancer.

Dr. Patriota pointed out that it is unlikely that a single vitamin can improve cardiovascular health:

“The most important behavioral risk factors for cardiovascular health are inadequate diet, physical inactivity, tobacco use, and harmful use of alcohol. Therefore, improving cardiovascular health is important to invest in lifestyle changes — smoking cessation, adopting a healthier diet, and increasing physical activity.”

However, Dr. Patriota said vitamin D deficiencies must be detected and treated, especially in populations at risk for vitamin D deficiency.

“Vitamin D supplementation for the general population is not recommended in most countries,” she explained. “People at risk of vitamin D deficiency need to adequately measure their vitamin D level. If the risk or diagnosis of deficiency or insufficiency is identified by a specialized professional, the supplement can be prescribed.”

“There are vitamin D supplements suitable for different situations,” Dr. Patriota added. “The risk of using vitamin D supplements without professional guidance is that high levels of vitamin D can promote hypercalcemia, hypercalcification of tissues, kidney overload, and other clinical complications.