Calcium Supplementation May Cause 30% Greater Risk of Heart Attack
Patients with the bone-eroding disease of osteoporosis have long been directed by their physicians to supplement their food intake with calcium in the hope of preventing further damage to their bone structures. According to the government fact sheet, researchers also believe that calcium helps in the reduced risk of colorectal cancer.
As with many studies involving food and supplement intake, the tide is ever changing in the way researchers interpret the data, and the studies are not always consistent.
On February 21, 2007, Science Daily published an article that stated that calcium supplementation had no effect on heart disease. The trial to which the article referred, studied 36,282 postmenopausal women, over a seven year span of time. Half of the women were given 500mg calcium carbonate and 200 IU of vitamin D and the other half took a placebo. The results were very similar (499 heart attacks and 362 strokes in the calcium/vitamin D group vs. 475 heart attacks and 377 strokes in those taking the placebo), which led to the declaration that calcium supplements were not a risk factor.
In contrast, less than three years later, researchers at the University of Aberdeen in the U.K. and Dartmouth University revisited calcium studies that were published between 1990 and 2007. These particular reassessments excluded any trials in which calcium and vitamin D were taken together. After analyzing the studies, they concluded that calcium supplementation alone increased heart attack risk by 20-30%.
Not everyone agrees with the latest findings. Cardiologist Nieca Goldberg, MD. believes, "It is hard to understand how calcium could increase the risk for heart attack and not for stroke or death if this association is real." U.K. Hull York Medical School Cardiologist John Cleland is not convinced either, and in fact is not convinced that calcium or calcium with vitamin D protects against bone fracture, further proving that medicine is not an exact science.