‘What Vitamin D Can Do for Your Heart’
Many of us are concerned about vitamin D insufficiency since it affects our bones. Our bodies can’t properly absorb the calcium that our bones require to keep strong if we don’t get enough vitamin D. However, research reveals that there may be additional reasons to ensure that you get enough of this nutrient, such as heart disease.
According to a recent study published in the European Heart Journal, those who are deficient in vitamin D are more prone to develop heart disease and high blood pressure than those who have normal vitamin D levels. The participants in the study who had the lowest levels of vitamin D in their blood had a risk of heart disease that was more than doubled. Vitamin D insufficiency is unfortunately fairly frequent.
Vitamin D is also referred to as the “sunshine vitamin.” This is because vitamin D is produced in our systems as a result of a chemical reaction between natural sunlight and our skin. Although some foods contain more vitamin D than others — egg yolks and oily fish such as salmon and sardines are both good sources — the amount of vitamin D obtained from a healthy diet is insufficient on its own, according to Erin Michos, MD, associate director of Preventive Cardiology at Johns Hopkins University School of Medicine. As a result, vitamin D can be a challenging nutrient to consume in sufficient amounts.
According to a global update on vitamin D deficiency released in 2020, roughly 5.9% of the U.S. population has severe vitamin D deficiency, while another 24% has insufficient levels. Although there is some disagreement over how much vitamin D is needed, the US Institute of Medicine recommends that the average individual get between 400 and 800 IU (10 to 20 micrograms) of vitamin D per day.
The study discovered an L-shaped risk, with those with severe vitamin D deficiency having the highest risk of heart disease, and those with adequate levels having a risk that flattens out. People with a Vitamin D content of more than 50 nmol/L (20 ng/mL) in their blood had no additional heart health benefits, according to the researchers.
So, how does this research affect you?
This is when things become a little complicated. The fact that there is a link between low vitamin D and cardiovascular illness does not prove that low vitamin D causes heart disease. In fact, according to Elina Hypponen, PhD, director of the Australian Centre for Precision Health and main author of a study published in the European Heart Journal, low vitamin D levels are most likely a sign of poor health. People who can’t or don’t get outside very often are more likely to be vitamin D deficient because we acquire the majority of our vitamin D from the sun. This includes people with chronic diseases or disabilities that prevent them from spending much time outside, people who spend the majority of their time at home for any reason (as many of us did during the COVID-19 pandemic), and people who cover the majority of their skin while out in the sun for cultural or religious reasons. Of course, spending too much time in the sun without protection carries its own set of problems. “People who spend all day in the sun are at danger for skin cancer,” says Dr. Michos, who adds that even brief periods of time make a difference. In the summer, 15 minutes of standing outside at noon would suffice. So don’t forget to apply sunscreen.
However, there are periods of the year when the sun doesn’t shine nearly as much as it should, and there are reasons why some people can’t or won’t go outside even when it’s sunny. Supplements may be used in these situations. Yet. Dr. Michos, who has spent much of her career studying the link between low vitamin D levels and heart disease, advises against using supplements. “People with low vitamin D levels in their blood have a higher chance of high blood pressure, heart attacks, strokes, heart failure, and all of these horrible things,” she explains. “And the question is always, ‘Can you prevent these outcomes if you address the vitamin D?’”
Dr. Michos was once thrilled about vitamin D pills since they appeared to have the potential to help with all of these health issues. However, the VITAL trial, which included more than 25,000 participants using daily vitamin D3 supplements over several years, was published in 2018 by Brigham and Women’s Hospital. Vitamin D supplementation did not diminish the risk of heart attack, stroke, or cardiovascular mortality, according to the VITAL trial.
Furthermore, there is a risk of taking too much vitamin D, particularly because it is a fat-soluble vitamin, which means it lasts longer than water-soluble vitamins such as vitamin C. When you consume too much vitamin C, you will pee out the majority of it. When you consume too much vitamin D, it accumulates in your fat.
Dr. Michos was a participant in a trial that randomly assigned elderly people to one of four vitamin D supplement doses. “Both low and high levels were connected with danger,” she says, citing her and other research.
Her advice is to only use vitamin D supplements if a doctor has determined that you are vitamin D deficient. Unfortunately, the United States Preventive Services Task Force, which studies whether health screenings are important for good health, has determined that the advantages of regular vitamin D insufficiency screening are insufficient. That isn’t to say that if you want to know your levels, you can’t have a blood test. However, it is likely that your insurance will not cover the expense.
So, how can you tell whether you’re in danger?
Because the sun provides the majority of our vitamin D, you can obtain a fair estimate of how deficient you are. According to Dr. Hypponen, genetic variation can have a slight impact on vitamin D levels, but genetics alone does not determine deficiency. “Sunlight-induced synthesis is by far the most essential source of vitamin D, therefore persons who do not spend time outside during the daylight hours for any reason, who have darker skin color, or who wear a cultural garment that does not leave skin exposed are most at danger,” she explains. In the winter, when the sun isn’t shining as much, most people’s vitamin D levels drop.
Even these criteria, though, might be difficult. Because dark skin blocks some of the reaction that produces vitamin D and fat holds onto the vitamin, both people with dark skin and people with higher levels of body fat are likely to have lower blood levels of vitamin D. Dr. Michos says, “This always gets to the question of what’s too low.” “Because, surprisingly, Black women are considerably less likely than white women to suffer from fractures, and they also have higher bone mineral density.” The same can be said for persons who have a lot of body fat. We do know, however, that low vitamin D levels are linked to an increased risk of bone disorders.This shows that the amount of vitamin D required for good health isn’t constant — like so many other aspects of health, it is likely to vary depending on your unique body.
Overall, Drs. Michos and Hypponen advise against using vitamin D pills unless you are sure you need them. Supplements can help those who are actually lacking in vitamin D, but they’re unlikely to help and may even be dangerous if your vitamin D levels are adequate.
