Calcium causes heart disease

Too much harms the heart

The total intake should not exceed 1500 mg. In addition, there is a good supply of vitamin D: either through exposure to sunlight and thus endogenous synthesis or - if this is not guaranteed - through supplementation of 800 to 2000 I.U. D3 daily. Two recent studies show that caution is advisable with calcium. Swedish researchers found that women who regularly consume a lot of calcium have a higher risk of death, especially from cardiovascular diseases. The critical amount was 1400 mg per day. Previously, a US study had found an increased cardiovascular risk in men with high calcium intake (1500 mg / day).


Significantly more ischemia in women


The scientists around Professor Dr. Karl Michaëlsson from Uppsala University analyzed the data of 61,443 women from the Swedish mammography cohort who were asked about their diet and supplements between 1987 and 1990 (1). The mean calcium intake was 572 mg / day in the lowest quartile (corresponds to about five slices of cheese) and 2137 mg / day in the highest. The researchers put this in relation to death dates.


In the next 19 years, 17 percent of women died, a third of them from cardiovascular disease, 16 percent from heart disease and 8 percent from stroke. Women who consumed more than 1,400 mg calcium per day were more than twice as likely to die of ischemic heart disease as women who consumed between 600 and 1,000 mg. Overall mortality and the rate of cardiovascular diseases were also significantly increased. But even with an intake below 600 mg / day, the risk of death was increased.


Taking supplements, usually 500 mg calcium per day, was not per se risky. Exception: women who ingested more than 1400 mg calcium with their food and also swallowed tablets. Here the risk of death was more than doubled. The researchers suspect that a very high or very low calcium intake could overwhelm the body's own homeostasis and change the calcium blood level. Therefore, older women should only resort to supplements if they are low in calcium with their food.


Men's hearts also suffer


A prospective observational study published at the beginning of February showed that too much calcium also harms men's hearts (2). Qian Xiao from the US National Cancer Institute in Bethesda / Maryland evaluated data from the Diet and Health Study. The influence of diet on health was examined in 388,000 men and women between the ages of 55 and 71. 51 percent of men and 70 percent of women took calcium supplements. During the observation period of twelve years, 7904 men and 3874 women died of cardiovascular diseases.


Taking supplements increased men's risk of dying from heart disease by 20 percent. The risk of cerebrovascular death was not increased. There was no association with women. Dietary calcium intake did not affect the risk of death in either men or women.


Xiao found a U-shaped curve for the men's cardiovascular risk. With a low total daily intake below 500 mg, the risk was increased, as was the case with more than 1500 mg. At the lower apex of the curve (around 1000 mg), she found a tendency towards protective effects. However, observational studies can only provide indications and no evidence of a causal relationship. That is reserved for an intervention study. /



  1. Michaëlsson, K., et al., Long term calcium intake and rates of all cause and cardiovascular mortality: community based prospective longitudinal cohort study. BMJ 346 (213) 1228.
  2. Xiao, Q., Dietary and Supplemental Calcium Intake and Cardiovascular Disease Mortality. The National Institutes of Health-AARP Diet and Health Study. JAMA Intern Med. (2013).