The Calcium Controversy

It is well established that consumption of calcium-rich foods or calcium supplementation can help prevent osteopenia and osteoporosis,
especially in postmenopausal women. Consequently, calcium supplements are widely used to combat estrogen- and age-related declines in bone mineral density, especially in those with a diet deficient in calcium-rich foods.

Twist in the tale:

But recent data suggest that high calcium intake might increase the risk for myocardial infarction (MI)

or heart attack. It is uncertain exactly how calcium supplements work to increase MI risk, but calcium supplements can accelerate vascular calcification (calcium deposits on blood vessel walls).

Current guidelines suggest that most adults should receive between 1000 mg and 1200 mg of elemental calcium daily. Individuals who consume a healthy diet, rich in dairy products and calcium-fortified foods, should reach these thresholds without any supplements. Blood calcium levels increase much faster after taking calcium supplements than they increase after dietary calcium. High levels of calcium in the blood can thus cause vascular calcification.

The EPIC-Heidelberg study was undertaken to evaluate the associations of dietary calcium intake and calcium supplementation with MI, stroke(paralysis) risk, and overall cardiovascular mortality.
The results indicated that calcium supplement users experienced a statistically significant increase in MI risk when compared with those who did not use any supplements.


The National Institutes of Health trial was also based to study the same facts.
Supplemental calcium (1000 mg daily) was associated with a 19% increase in CV death, including heart disease death in men but not in women as compared to no calcium supplementation.


Now comes a another twist in the story:

Analysis of the EPIC-Heidelberg study revealed serious flaws. A 2009 study from the Mayo Clinic actually measured aortic valve and coronary calcification for up to three years after the patient started taking calcium supplements. They, however did not find any significant progression of calcification.
Thus, the validity of the results of the EPIC study was questioned.

Moral of the story:

Calcium rich foods

Calcium supplements should be reserved for patients who, through careful dietary history, do not consume adequate amounts of calcium, unless otherwise clinically indicated. The total calcium intake should not exceed 1200 mg per day. Perhaps the sage advice of getting one's vitamins and minerals primarily from dietary sources applies here too, at least for a majority of patients. Given the recent finding that calcium supplements may increase CV mortality in men, the consumption of calcium-rich foods, such as low-fat dairy products, beans, and green leafy vegetables, may be preferred over calcium supplements in men, unless otherwise clinically indicated.