If you notice any of these symptoms and you think the amount of calcium you have been taking could be the source of the problem, stop using the supplements and call your doctor. If you think your heartbeat is either irregular or slow, seek medical attention immediately. The basic allowance for everyone 18 years of age and older is 800 milligrams. Women need an additional 400 milligrams of calcium each day during pregnancy and as long as they breastfeed. Do not take megadoses of calcium during pregnancy or while breastfeeding.
Calcium does pass into the breast milk.
The body only absorbs part of the calcium it takes in, and different forms of calcium provide varying amounts of this mineral. Calcium citrate may provide a bit more usable calcium than other forms, and is less likely to have side effects. Calcium carbonate is often recommended because it contains the highest percentage of absorbable calcium. It is also the cheapest and has the added advantage of acting as an antacid. To get the same 1,000 milligrams from other forms of calcium, you need to take up to 12 tablets a day.