Most women have been told by their medical doctors to get 1200-1500 mg of calcium per day. Women are scared into believing that this one nutrient stands between healthy bones and broken hips! No regard is given to the type of calcium suggested. In fact, many are told to just take Tums or any over- the-counter product. These forms of calcium and the majority on the shelves are made from limestone, oyster shell, or bone meal. Osteoporosis is not caused by a lack of limestone, oyster shell or bone meal. Heart attacks, however, may be caused by supplementation with these exact same "elemental" forms of calcium, according to two meta-analyses published last year in the British Medical Journal.
The idea that calcium supplementation may be toxic to cardiovascular health is not new, as many of us in the field of nutrition have long warned against taking this type of elemental calcium. Inorganic or "elemental" calcium, when not bound to the natural co-factors, e.g. amino acids, lipids and glyconutrients found in real food, no longer has the intelligent delivery system that enables your body to utilize it in a biologically appropriate manner. Lacking this "delivery system," the calcium may end up going to places you do not want (ectopic calcification), or go to places you do want (e.g. the bones), but in excessive amounts, stimulating unnaturally accelerated cell-division and resulting in higher bone turn over rates later in life. Or, the body attempts to remove this inappropriate calcium by dumping it into the bowel (constipation), or pushing it through the kidneys (stones). Worse, high levels of calcium can accumulate in the blood and lead to atherosclerotic plaguing, hypertension (that's why we use calcium channel blockers to lower blood pressure), and perhaps causing arrhythmias/fibrillation and or heart muscle cramping (a rather common, though rarely recognized trigger of 'heart attack').
"Brain gravel" is also an increasingly prevalent phenomenon, where autopsied patients have been found to have pebble-size calcium deposits distributed throughout their brains, including the pineal, ('the seat of the soul').
The breasts too are uniquely susceptible to calcification, which is why we use the same x-rays to ascertain bone density that we do to discern pathological microcalcifications in the breast, i.e. x-ray mammography. Due to the fact that the hydroxylapatitate crystals found in malignant breast tissue may act as a cellular "signaling molecule" or mitogen (inducing cell proliferation), it is possible that certain breast calcifications may be a cause, and not just an effect, of the tumorous lesions ("breast cancer") found there. This may also help to explain why women with the highest bone density (often obtained through massive, lifelong calcium supplementation) have up to 300% higher incidence of malignant breast cancer.
If you have concerns about your bone health, than you need to look at more important factors than calcium. Are you engaged in habits that erode bone? (ex. caffeine, sodas, vinegars, lack of exercise, lack of sun exposure) Does your diet include a large and varied amount of fruits and veggies? Do you include citrus, melons, cruciferous veggies, seaweeds, and a lot of leafy greens? After considering all of this there may be a place for additional supplements but calcium is not on top of the list.