Calcium, Vitamin D and Heart Health

Calcium and vitamin D supplementation may have no effect on heart health, a new study suggests.

Researchers from George Washington University studied the effect of calcium and vitamin D supplementation on coronary or cerebrovascular risk in healthy, postmenopausal women.

The researchers explained that individuals with vascular or valvular calcification are at increased risk for coronary events (heart problems), but the relationship between calcium consumption and cardiovascular events is uncertain. Scientists evaluated the risk of coronary and cerebrovascular events in the Women's Health Initiative randomized trial of calcium plus vitamin D supplementation.

Researchers randomized 36,282 postmenopausal women 50 to 79 years of age at 40 clinical sites to calcium carbonate 500 mg with vitamin D 200 IU twice daily or to placebo. Cardiovascular disease was a prespecified secondary efficacy outcome.

During seven years of follow-up, myocardial infarction (heart attack) or coronary heart disease death was confirmed for 499 women assigned to calcium/vitamin D and 475 women assigned to placebo. Stroke was confirmed among 362 women assigned to calcium/vitamin D and 377 assigned to placebo. In subgroup analyses, women with higher total calcium intake (diet plus supplements) at baseline were not at higher risk for coronary events or stroke if assigned to active calcium/vitamin D.

Researchers concluded that calcium/vitamin D supplementation neither increased nor decreased coronary or cerebrovascular risk in generally healthy postmenopausal women over a seven-year use period.

Comments

[Emily]

This study on the relationship between calcium and heart health is very clinically relevant because of the high incidence of cardiovascular events and the common use of calcium and vitamin D to prevent osteoporosis in women. This was a very large, long-term, randomized controlled trial that enrolled women from 40 different sites. It is very likely that the resulting evidence is applicable to a large real-world population.

The Women’s Health Initiative is a very well-respected research program, which has generated solid therapeutic data that have shaped the way women receive healthcare today.

[Dexter Otis Grenne]

This seems like a very well-executed experiment. I assume the results can be applied to men as well. I'm not sure why they didn't set up a second study group composed of men while they were testing women.

[Cultural relativism]

I’m pretty savvy in the supplements and herb market, but I’ve never heard anything about taking calcium and vitamin D for heart health. Was such supplementation primarily advocated by orthodox Western medicine as a strategy for reducing cardiovascular risk? Or perhaps there was preliminary research to this effect?

I wonder why this study didn’t take strokes into account.

[Cultural relativism]

This is an interesting study to be sure. Many of my health-savvy female friends with chronic illnesses feel as if they should take a daily calcium supplement. A lot of them also taken vitamin D, and not just because the risk of osteoporosis is always on our minds. Some lower quality sources of evidence have touted this combination to stave off progression of disease states in recent years. But this advocacy to take calcium and vitamin D for chronic disease states is increasingly questioned by studies which claim little effect of this combination for purposes other than keeping our bones healthy.

To further confound the situation, a May 2006 NIH State-of-the-Science Conference Statement on Multivitamin/Mineral Supplements and Chronic Disease Prevention said, “most of the studies we examined do not provide strong evidence for beneficial health-related effects of supplements taken singly, in pairs, or in combinations of three or more.” A single, dual, or multivitamin surely has general health benefits, especially for those of us who tend to eat on the run. But could the anxiety my friends feel over remembering to abide by the multi-pill regimen each has constructed to address an array of specific problems in their health profiles cause more immediate anxiety than the disease state itself?

[D B Martin]

The NIH statement posted by Cultural Relativism makes it clear - taking a vitamin pill is no substitute for eating a healthy diet. In fact, too much calcium can lead to calcium deposits in soft tissues, including blood vessels, which be downright dangerous in the cardiovascular system. And, too much vitamin D can lead to increased bone resorption and osteoporosis.

I agree with the NIH and Bryan: A multi-vitamin with reasonable doses of vitamins can be helpful during busy periods of eating on the run, but otherwise... just eat sensibly!

[Cady]

This sounds like a well-executed study, however, I still have a few questions. As Dexter said above, why weren't men included in the study? Also, I wonder if calcium and vitamin D consumption PRIOR to menopause contributed at all to heart health. It is commonly known that once women reach menopause their bone calcium (and bone density) increases at a much higher rate than in their younger years. Suppose these women were adequately maintained on Calcium and vitamin D leading up to menopause, would it have made a difference?

[Ceadda Wilcox]

Could calcium have had no effect because it was not taken with magnesium, as new reports are suggesting? Otherwise, I've heard that our bodies and particularly our bones are unable to absorb the calcium so the supplement is worthless? I would be interested in more information about the type of calcium supplement the women were taking.

[Emily P.]

I was wondering the same thing as Cady. I feel like waiting until after menopause to take preventative measures regarding your health is simply too late. I'm also curious as to whether or not this study would have had beneficial results if the age demographic were much younger.

[MV]

I have the same question as Ceadda. What should you take along with the calcium supplements to make them effective or more effective?

[Paul]

It is great to see that calcium with or without vitamin D does not increase the risk for sudden coronary problems. This is especially comforting when it's known that plaques that build up in arteries and cause stroke, heart attacks, and death contain a lot of calcium. Before this, I don't think it was clear what role calcium intake played into plaque formation. No one wants to ward off osteoporosis if it is going to cause a heart attack. Now, older women can take their minerals without fear, and they can hopefully prevent osteoporosis from worsening.