The major role of Calcium is in maintaining integrity of the skeletal system, which stores 99 percent of the body's Calcium. The skeletal system is quite dynamic, in that as new calcium crystals are forming, old ones break down. By age 40 to 50, the resorption or tearing down down may exceed the deposition or building up and total bone mass may gradually decline. Shorter, white females are most at risk for osteoporosis, and heredity plays a role also.

Stress, immobilization, spinach, phytic acid (found in the bran of whole grains), cocoa, soybeans, and foods high in phosphate content (includes carbonated sodas and grains) reduces your ability to adequately absorb Calcium. Caffeine increases the loss of Calcium through the kidneys.

Gastric/hydrochloric acid must be present in the stomach for proper absorption; a lack of this acid is from taking large doses of antacids and acid inhibiting drugs for ulcers. Also light meals enhances absorption better than an empty stomach and diets high in protein absorb 10 percent more Calcium. And diets high in sugars and other carbohydrates weakens bones. Sugar acidifies the blood and forces calcium out of the body. That is why milk (lactose) is not an ideal source of Calcium.

Increased Calcium intake without adequate Phosphorus (readily available milk, meats, poultry, fish, eggs, grains, nuts, dried beans, peas, Royal Jelly) may inhibit the synthesis or absorption of Vitamin K, which in theory could cause a decrease in normal blood clotting.

Those with insomnia, Calcium is also a potent sleep inducer!

Finally, supplements may guard against cancers of the endometrium, pancreas, and colon.1 With a daily 1250 mg. dose of Calcium carbonate, the proliferation of colonic epithelial cells decreases. Another study of 1900 men found that 1200 mg. per day reduced the incidence of colon cancer by 75 percent.2 

1200 mg. for both sexes aged 11-24; those over 25 should consume 800 mg. to prevent bone loss. Pregnant and lactating of all ages require 1200 mg. per day. Increased requirements for women at greater risk for osteoporosis (because of family history) as well as those under increased stress, those bedridden, immobile because of injury, or illness would militate for a slightly higher dose, around 1500 mg. a day.