Health library

Nov. 7, 2022—Vitamin D helps keep our bodies healthy. It strengthens our bones. It supports our immune system as it fights off bacteria and viruses.

And because people who have higher levels of vitamin D are less likely to have heart disease, the National Institutes of Health (NIH) sponsored a study to find out if vitamin D supplements might be able to keep people heart-healthy.

But if you've been taking vitamin D supplements for your heart, there's something you should know: More is not better.

An ongoing study supported by the NIH showed no benefit from moderate or high-dose vitamin D supplements. They compared people taking at least 1,000 IU of vitamin D to people taking a placebo. For most people, these doses did not reduce risk for having a heart attack, stroke or cardiovascular death.

More isn't better

Getting too much vitamin D can be harmful. Adults shouldn't get more than 4,000 IU of vitamin D a day from supplements or food. It can cause high calcium levels in the blood, which can lead to:

• Nausea.
• Vomiting.
• Muscle weakness.
• Confusion.
• Pain.
• Loss of appetite.
• Dehydration.
• Excessive urination and thirst.
• Kidney stones.

Plus, extremely high levels, usually caused by taking excessive amounts of vitamin D dietary supplements, can cause kidney failure, irregular heartbeat and even death.

How to get enough vitamin D

The NIH recommends a daily intake of 600 IU of vitamin D—mostly from food and beverages— for people age 1 to 70. Older folks should aim for 800 IU.

Instead of taking supplements, try these ways to get safe amounts of vitamin D.

• Get outdoors. Your body creates vitamin D when the sun shines on your bare skin. For most people, it takes just 15 minutes a few times a week to get enough. That way, you can avoid taking supplements. And, while you're out there, why not walk, run or do other heart-healthy activities?
• Eat your vitamin D. Go for fatty fish, fortified dairy products and cereals, and certain mushrooms that are exposed to ultraviolet light while growing.
• Check food labels. Assess how much vitamin D you're getting by looking at the numbers. That way, you can avoid getting too much of a good thing.

How to help your heart

Since taking too much vitamin D won't help your heart, what else can you do? Here are six ways to prevent heart disease.