New research claims these two supplements taken together could be dangerous—but should you be worried?

By Maggie O'Neill
July 09, 2019

Research published yesterday announced that taking calcium and vitamin D supplements together might increase your risk of having a stroke. This finding was published in the Annals of Internal Medicine in a review of what’s currently known about the effects of supplements on our health.

The review prompted some scary headlines considering more than half of Americans take a dietary supplement of some sort, and calcium and vitamin D are among the most common.

Research previously published in the Journal of Nutrition found that 37% of Americans took vitamin D and 43% took a calcium supplement.

Why do we need calcium?




Why do we need vitamin D?

Vitamin D, which is important for children and adults, also plays a part in protecting bones and helps support your muscles. Without adequate levels of vitamin D, you have an increased risk of breaking bones as you get older, the National Osteoporosis Foundation says.

Among the most popular ways to get vitamin D is going outside. When sunlight reaches your skin, your body makes vitamin D and stores it. Additionally, you can get it from fatty fish, including wild-caught mackerel, tuna, and salmon. Vitamin D can also be found in orange juice, fortified cereals, soymilk, and dairy products, including milk.

What does the new research say?

This isn’t the first time the combination of calcium and vitamin D has been the subject of health stories. “It’s been looked at a lot. A few years ago, articles came out that said the same thing,” Stephen Kopecky, MD, a cardiologist at Mayo Clinic, tells Health.

Dr. Kopecky explains that you shouldn’t panic if you’ve been taking vitamin D and calcium supplements together. The authors of the new report looked at previously published evidence concerning how supplements affect our health.


Dr. Kopecky says studies that don’t rely on questionnaires later found that use of calcium and vitamin D supplements did not increase one’s risk of stroke or heart attack. “That has no correlation whatsoever,” he says. (However, a number of factors can increase your risk of having a stroke, including being overweight, binge drinking, and not getting enough exercise.)

He adds that if you’ve been told to take calcium and vitamin D supplements by your doctor, you shouldn’t stop. If you’ve been taking the supplements on the advice of someone else, though, you might want to reevaluate. “I would speak to a caregiver or primary care provider. Say, ‘Do I really need this stuff?’”

How should you be getting vitamin D and calcium?


“A pill doesn’t make up for our deficient lifestyle. That’s what every study has shown,” he explains.

“It’s always better to get it in your diet if you can. People tend to take supplements to make up for their diet. [Therefore, supplement use] can be a marker of a bad diet.”