Vitamin D supplementation may not reduce the risk of heart disease

By Angela Betsaida B. Laguipo, BSNJun 20 2019

It is well established that vitamin D deficiency is a risk factor for the development of heart disease. Now, scientists have confirmed that taking vitamin D supplements does not reduce the risk of cardiovascular disease.

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For many years, scientists have suggested that vitamin D deficiency is a key driver for a broad range of health problems, including heart disease, diabetes, depression, and brittle bones. Cardiovascular diseases (CVD) have been linked to low levels of vitamin D in the body, and doctors recommended supplementation to prevent heart disease.

Vitamin D has no effect on CVD risk

Despite several studies looking for the link between vitamin D deficiency and poor heart health, there isn’t much evidence to prove that low levels of vitamin D can cause heart disease or that getting enough of the vitamin can prevent this condition.

Researchers at Michigan State University recently analyzed 21 clinical trials into vitamin D. They found that taking vitamin D supplements does not prevent heart attack, heart disease, stroke, or death from cardiovascular disease.  

The World Health Organization (WHO) reports that cardiovascular diseases are the leading cause of death worldwide. This means that more people die each year from CVD than from any other cause. In 2016, 17.9 million people died from CVDs, accounting for 31 percent of all deaths worldwide.

The American Heart Association (AHA) reports that CVD accounted for 840,678 deaths in the United States in 2016. Approximately 121.5 million people in the country had some form of CVD between 2013 and 2016, alone.

No difference in risk between two experimental groups

For the current study, which was published in the Journal of the American Medical Association Cardiology, the researchers recruited 83,291 patients, of whom, more than 41,669 received vitamin D supplements and 41,622 received placebos.

The researchers wanted to determine the link between vitamin D and the reduction of CVD risk among patients. The results of the study show that as many people in the Vitamin D group suffered strokes, heart attacks, and died of cardiovascular problems as did those who are in the placebo group.

"We thought it would show some benefit. It didn't show even a small benefit. This was surprising,” Mahmoud Barbarawi, the chief resident physician at the Hurley Medical Center in Michigan, and a clinical instructor in the MSU College of Human Medicine said in a statement.

The findings were consistent even when gender was taken into consideration. There is no difference in the risk between women and men.

There are a lot of things people can do to lower cardiovascular risk - doing regular exercise, healthy eating, stopping smoking, and controlling hypertension and diabetes. But giving vitamin D supplements for the sake of lowering cardiovascular risk is not recommended.”

Mahmoud Barbarawi

The researchers suggest that doctors and patients should think twice about taking vitamin D supplements to lessen the chances of having a hard attack or other cardiovascular diseases.

Though the study showed no risk reduction in heart diseases, patients who are being treated for bone problems such as osteoporosis, still might benefit from vitamin D supplementation.

What is vitamin D and why do we need it?

Vitamin D, also known as the sunshine vitamin, is a fat-soluble vitamin is produced by the body when the skin is exposed to the sun. Vitamin D is important for maintaining healthy bones. It has been also shown to protect against many illnesses, including type 1 diabetes, multiple, sclerosis, and cancer.

The human skin produces vitamin D when exposed to the sun. People living farthest from the equator tend to have lower vitamin D levels in the blood. Though supplementation is recommended, it mostly targets making the bones healthy and strong. This vitamin plays a pivotal role in the calcium and phosphorus maintenance in the blood. It also aids in the absorption of calcium in the intestines.

The recommended daily intake of vitamin D is 400 to 800 IU, or 10 to 20 micrograms. Major sources of vitamin D include sun exposure and food sources, such as cod liver oil, herring fish, swordfish, salmon, tuna, egg, chicken, maitake mushrooms, fortified skim milk, beef liver, and cheese.

Vitamin D deficiency may result in obesity, hypertension, fibromyalgia, chronic fatigue syndrome, diabetes hypertension, depression, and osteoporosis. The common signs and symptoms include fatigue, painful bones, back pain, depressed mood, hair loss, muscle pain, hair loss, and getting sick more often than usual.