Calcium is essential to maintain the body. Virtually all our cells require calcium, and if we don’t get enough, our bodies rob the calcium in our bones. As we age, our calcium requirements go up, and our ability to absorb it goes down.
Foods we eat can inhibit the absorption of calcium. Iron (commonly added to multi-vitamin supplements) interferes with calcium absorption, as does fiber, and the aluminum in antacid tablets. Too many carbonated colas (which contain phosphorus) inhibit calcium utilization, and so does alcohol.
Calcium is good for fighting stress, and people who don’t get enough calcium often complain of restless sleep and muscle cramping. The better you sleep, the better you are able to handle the next day. Calcium is a natural sleep aid!
Do you get enough calcium, and is it the right kind? We get calcium in foods such as dairy products like milk, cheese and yogurt, but many folks are lactose-intolerant so drinking milk is out of the question. Some vegetables like broccoli contain calcium. Green leafy vegetables like spinach and chard contain lots of calcium BUT they also contain oxalates, which bind calcium into insoluble salts.
Bioavailability of calcium varies with the type of calcium, and whether it is in food or supplements. Many of us take calcium supplements, which vary in the form of calcium used; they vary in the amount of elemental calcium they contain.
Studies have shown that calcium supplements are not all alike, and some of us cannot absorb the calcium in them due the kind of calcium or binder used. Some of the forms of calcium are calcium carbonate, calcium citrate, coral calcium (a kind of calcium carbonate), a microcrystalline form called MCHC, and chelated calcium.
Generally, the amounts of absorbable calcium breaks down like this: dairy products, 25-35%. In supplemental forms it’s calcium carbonate, 40%; calcium citrate 21%; calcium lactate 13% and calcium gluconate, 9%. That’s the percentage of the total calcium contained… so if a tablet contains 500 mg of calcium carbonate, at best we can only absorb 40%, or 200 mg.
WHEN to take calcium is as important as how much. Our systems can only absorb so much calcium at one time, so divide up when you take calcium into several doses a day. Calcium taken at bedtime seems to have a beneficial effect not only on sleep, but on bone-building as well.
Remember the old cure-all of drinking a cup of warm milk at bedtime? It works!