Constipation, bloating, and gas are sometimes reported with the
use of calcium supplements.4 A very high intake of calcium from
dairy products combined with large amounts of supplemental
calcium carbonate (used as an antacid) was reported in the past
to cause a condition called "milk alkali syndrome." This
toxicity is rarely reported today because most medical doctors
no longer tell people with ulcers to use this approach as
treatment for their condition. People with hyperparathyroidism,
chronic kidney disease, or kidney stones should not supplement
with calcium without consulting a physician. For other adults,
the highest amount typically suggested by doctors (1,200 mg per
day) typically does not cause side effects. People with prostate
cancer should avoid supplementing with calcium without medical
supervision. A combined analysis of 15 controlled trials found
that long-term calcium supplementation was associated with a
significant increase of approximately 30% in the incidence of
myocardial infarctions (hea