Answer: If a woman do not consume enough calcium to sustain the needs of your developing baby, your body will take calcium from your bones, decreasing your bone mass and putting you at risk for osteoporosis. Osteoporosis causes dramatic thinning of the bone, resulting in weak, brittle bones that can easily be broken . The bone tissue turns over, or "demineralizes" more rapidly than bone in other pregnant women and releases locked up lead into the blood.