If You Take These 2 Supplements, Your Stroke Risk May Be High, Study Says

Taking them together could increase your risk by nearly 20 percent, research shows.

We've all spent most of the past year worrying about our health. To look at it on the bright side though, that could mean you've made some healthy changes to your lifestyle recently. However, if you started taking supplements to help boost immunity or as preventative care, you need to make sure you're reaping the benefits and not putting yourself at risk of another serious condition. Researchers behind a 2019 Johns Hopkins meta-analysis suggested a predominant number of vitamins don't increase longevity or lower the risk for cardiovascular disease or stroke. But even worse, combining two supplements in particular could have an adverse affect, and may increase your risk of a stroke. Keep reading to learn what they are, and if you're wondering what you should take, These Are the Only 2 Supplements That Help You Live Longer, Study Finds.

If you take calcium and vitamin D together, you may have a 17 percent higher risk of stroke.

hand holding supplements in hand, calcium and vitamin d
Irina Timokhina / Shutterstock

The 2019 meta-analysis from Johns Hopkins Medicine researchers, published in the Annals of Internal Medicine, explored 277 clinical trials with 24 various interventions to determine which supplements benefit your health, including when taken in tandem.

After analyzing 20 studies that assessed the combination of calcium with vitamin D in supplement form, the researchers found 3,690 patients had strokes during the trials out of 42,072 total research participants. The researchers determined that taking calcium and vitamin D together had a 17 percent increased risk for stroke, which they deemed a "slightly increased stroke risk."

Additionally, a 2016 study published in Osteoporosis International on calcium and vitamin D reached a similar conclusion. "We conclude that the moderate effect of supplemental calcium and vitamin D on the risk of fractures is not large enough to outweigh the potential increased risk of cardiovascular disease, specifically in women who are at a low risk of bone fracture," the study's lead author Gunhild Hagen, then a PhD candidate at the Department of Public Heath and General Practice, said in a statement. And for one vitamin to avoid at the moment due to a recall, read up on why If You Take This Popular Vitamin, the FDA Says Stop Immediately.

Calcium and vitamin D are one of the most common supplement combinations.

Shot of a young man taking medication while standing at home during the day.

Calcium, which is important for bone growth and strength, and vitamin D—which you can get from sunlight and which helps the body regulate of calcium and phosphate—are both key for your well-being, according to the U.K.'s National Health Service. And these supplements are often taken together, Erin Michos, MD, director of Women's Cardiovascular Health at Johns Hopkins, told TCTMD, the Cardiovascular Research Foundation's site.

Michos says roughly a third of adults in the U.S. take both calcium and vitamin D, though the numbers are even larger in older adults. "More than 65 percent of women older than 70 years take calcium, while an excess of 60 percent of adults 65 years and older take vitamin D supplements," according to TCTMD. And for a vitamin that could benefit your body, This One Supplement Can Slow the Aging Process, New Study Says.

Calcium alone has also been linked to heart disease.

Calcium Supplements

There's long been concern with calcium supplements, with theories that the high, concentrated doses of the nutrient could quickly increase your blood calcium levels, making it more likely to be deposited in your arteries, according to Harvard Heart Letter.

A 2016 report published in the Journal of the American Heart Association, also out of Johns Hopkins, looked at 10 years of medical tests covering more than 2,700 patients to examine the causes of heart disease. They found that taking calcium in the form of supplements "may raise the risk of plaque buildup in arteries and heart damage."

"When it comes to using vitamin and mineral supplements, particularly calcium supplements being taken for bone health, many Americans think that more is always better," Michos, co-author of the study, said in a statement. "But our study adds to the body of evidence that excess calcium in the form of supplements may harm the heart and vascular system."

And for more supplements to be wary of, check out If You Take Too Much of This Vitamin, It Could Be Toxic, Experts Say.

Other research has shown there's not a definitive link between vitamin D and calcium and stroke risk.

business woman taking a pill to ease her headache.

Stephen Kopecky, MD, a cardiologist at Mayo Clinic, says if you've been taking calcium and vitamin D supplements simultaneously, you may be in the clear. "It's been looked at a lot. A few years ago, articles came out that said the same thing," Kopecky told Health. He notes that previous studies may have "lacked precision" and been subject to human error if they relied on questionnaires conducted for a deceased patient.

According to Kopecky, studies that didn't incorporate questionnaire responses found "no correlation" between vitamin D and calcium and an increased risk of stroke or heart attack.

Harvard Health Letter also points out that while there is some evidence of an increased stroke risk associated with calcium and vitamin D, "the largest and longest of these trials was the Women's Health Initiative, and it found no increased risk of heart attack or stroke in women taking both supplements together."

In fact, 2017 research published in the Journal of the American Heart Association found that vitamin D may actually help offset the risks associated with calcium and stroke. "This study suggests that calcium supplements given as monotherapy at high doses may increase the risk of ischemic stroke, whereas their combination with vitamin D seems to offset this hazard," the researchers concluded.

Clearly, there's no definitive answer, but as always, it's best to talk to your doctor about your specific situation. "I would speak to a caregiver or primary care provider. Say, 'Do I really need this stuff?'" Kopecky suggested to Health.

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It's always better to get calcium and vitamin D from food than supplements.

Healthy Foods

Kopecky also noted that research shows that pills don't replace a nutrient-deficient lifestyle. "It's always better to get [vitamins and nutrients] in your diet if you can. People tend to take supplements to make up for their diet," he said.

The 2016 Johns Hopkins research on calcium also concluded that the risks seemed specifically connected to ingesting the mineral as a supplement as opposed to consuming it through food. "A diet high in calcium-rich foods appears be protective," the researchers concluded.

According to WebMd, the top 10 calcium-rich foods are cheese, milk, yogurt, dark leafy greens, sardines, cereals like Raisin Bran and Total, fortified orange juice, soybeans, and enriched breads, grains, and waffles. Meanwhile, if you're looking to consume vitamin D in food form, you should eat salmon, canned tuna, egg yolks, mushrooms, and fortified foods like cow's milk, Healthline reports.

If you do need supplements, certain factors can also ensure you're taking them in the most healthy way possible. According to Harvard Health Letter, taking your calcium supplement with food, and limiting yourself to 500 mg at once is the best way to stay safe. As for vitamin D, the recommended daily allowance for adults is 600 IU, Johns Hopkins reports. And for more on the supplement to always avoid, This Is the One Vitamin You Should Never Take, Doctors Say.

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