Low levels of vitamin D are commonly found in people with heart disease, and research has shown a connection between low levels of this vitamin and a higher risk of the condition. This link raises many questions: Can vitamin D supplements benefit people with heart disease? How do you know if your vitamin D level is low? Are there any risks in supplementing your diet with vitamin D?

Here’s what you should know about the relationship between vitamin D and heart health and how to make sure you’re getting the right amount of this essential nutrient.

The Role of Vitamin D in Heart Health

Vitamin D is essential for healthy bones and teeth and strong muscles, and it helps support the immune system. Emerging research leads scientists to believe that vitamin D is also vital for cardiovascular health.

People with common cardiovascular diseases such as atrial fibrillation (Afib), coronary artery disease like angina or heart attack, and heart failure often have low vitamin D levels. Research also shows that people with underlying low vitamin D fare worse after being hospitalized for a heart attack.

One member shared her experience with low vitamin D and atrial fibrillation: “I was discharged from hospital after three days suffering an Afib attack and severe abdominal pain. The diagnosis has been vitamin D deficiency, thought to worsen Afib, and irritable bowel syndrome.”

More studies are needed to determine if vitamin D supplementation can help prevent or treat heart problems. Early research showed some promising results, but larger studies have since revealed that supplementation does not reduce negative events related to heart disease such as strokes or heart attacks. Currently, vitamin D supplements are not recommended universally by medical providers to help prevent or improve heart disease, as the evidence of their benefit has not been consistently proved in research studies.

Risk Factors for Vitamin D Deficiency

Vitamin D is often called the “sunshine vitamin” because our skin produces it when exposed to sunlight. Getting enough vitamin D can be a challenge because it’s not a nutrient naturally found in many foods. Some people may also be more likely to be deficient because of limited sun exposure due to climate or other factors, older age, skin tone, health conditions, or medications they take. You may have more trouble getting enough vitamin D if you:

• Have dark skin — Although melanin protects against sun damage, it can also reduce the skin’s production of vitamin D.
• Are an older adult — The body produces less vitamin D with age.
• Take medicine to lower cholesterol
• Have celiac disease, Crohn’s disease, or a history of gastric bypass surgery
• Have certain health conditions such as chronic kidney disease, type 2 diabetes, lymphoma, or osteoporosis
• Follow a vegan diet
• Are allergic or intolerant to food sources of vitamin D

If you’re concerned that you might be lacking in vitamin D, ask your health care provider for a blood test to check your vitamin D levels.

Three Ways To Increase Vitamin D Levels

You can boost your vitamin D status through sun exposure, food, and dietary supplements.

1. Be Smart About Sun Exposure

Although sunlight on your skin can increase vitamin D, too much sun can damage your skin and increase the risk of skin cancer and premature aging. It’s also difficult to measure how much sunlight is “enough” because different skin types and environmental factors, such as weather conditions and air pollution, affect vitamin D production. Guidelines suggest getting limited outdoor exposure to your arms and legs — 10 to 15 minutes in the sun, two or three times a week.

2. Eat Foods With Vitamin D

Some foods contain vitamin D naturally, and others are fortified during processing. Natural food sources include:

• Salmon, mackerel, sardines, tuna, and swordfish
• Cod liver oil
• Beef liver
• Egg yolks
• Mushrooms grown under ultraviolet light

Vitamin D is added to foods such as milk and other dairy products, breakfast cereals, orange juice, and plant-based drinks like soy or almond milk. You can see if a product has been fortified with vitamin D by checking the label.

Some foods high in vitamin D, such as egg yolks and cheese, may not be appropriate for everyone with heart disease or should be eaten only in certain amounts. Talk with your doctor about incorporating vitamin D-rich foods into your heart-healthy diet.

3. Consider Vitamin D Supplements

Food alone sometimes doesn’t provide a sufficient amount of vitamin D, so your doctor may recommend an over-the-counter supplement. You can find vitamin D as a stand-alone supplement, combined with calcium, or as part of a multivitamin. These supplements are available as pills or as liquids that you mix into foods.

There are two main forms of the vitamin: D2 and D3. Some researchers have reported that vitamin D3 works better for increasing vitamin D levels in the blood. The recommended daily intake of vitamin D for adults between ages 18 and 70 is 15 micrograms (mcg) or 600 international units (IU). Adults over 70 should aim for 20 mcg or 800 IU. The recommended amount may be different if you have a deficiency or for other health reasons.

Taking a vitamin D supplement with food isn’t necessary, but it can help enhance absorption.

MyHeartDiseaseTeam members frequently discuss taking vitamin D supplements, along with other vitamins. “I have vitamin D deficiency and take vitamin D3 daily with calcium, and it has helped in bringing my levels up,” one member wrote.

“My vitamin D level is very low in blood work, and now I will be on prescription-strength vitamin D for 12 weeks, one tablet each week,” another member wrote.

“I was also prescribed 50,000 IU of vitamin D per week after blood work showed very low levels,” one member shared. “After about two or three weeks, I could feel the results. Now after six months, I take 50,000 every other week.”

Can Too Much Vitamin D Be Harmful?

It is possible to get too much vitamin D. Too much vitamin D can lead to heart-rhythm abnormalities, as well as vomiting, nausea, weakness, and kidney damage. Almost all cases of overabundance can be traced to supplements. Although high exposure to the sun can have adverse effects, the body will not overproduce vitamin D.

Before you start taking vitamin D or any dietary supplement, speak with your health care provider. They can test the vitamin D concentration in your blood and determine if you’re deficient. They can advise whether a supplement could help, as well as which dosage and type of supplement would be safest and most effective for your situation.

If you begin taking a vitamin D supplement, you can get tested routinely in the months that follow to see if your level has improved.

Meet Your Team

MyHeartDiseaseTeam is the social network for people with heart disease and their loved ones. On MyHeartDiseaseTeam, you can connect with others who understand life with heart disease and share stories, give advice, or ask questions.

Have you talked with your doctor about vitamin D? Are you taking steps to boost your levels of vitamin D? Comment on this article, or share your thoughts by posting on your Activities page.