Who needs extra calcium?

Post-Menopausal Women
Menopause often leads to increases in bone loss with the most rapid rates of bone loss occurring during the first five years after menopause. Drops in estrogen production after menopause result in increased bone resorption, and decreased calcium absorption.
Annual decreases in bone mass of 3-5% per year are often seen during the years immediately following menopause, with decreases less than 1% per year seen after age 65. Two studies are in agreement that increased calcium intakes during menopause will not completely offset menopause bone loss.
Hormone therapy (HT), previously known as hormone replacement therapy (HRT), with sex hormones such as estrogen and progesterone, helps to prevent osteoporosis and fractures. However, some medical groups and professional societies such as the American College of Obstetricians and Gynecologists, The North American Menopause Society and The American Society for Bone and Mineral Research recommend that postmenopausal women consider using other agents such as bisphosphonates (medication used to slow or stop bone-resorption) because of potential health risks of HT if combination HT (estrogen and progestin) is solely being administered to prevent or treat osteoporosis. Postmenopausal women using combination HT to reduce bone loss should consult with their physician about the risks and benefits of estrogen therapy for their health.
Estrogen therapy works to restore postmenopausal bone remodeling levels back to those of premenopause, leading to a lower rate of bone loss. Estrogen appears to interact with supplemental calcium by increasing calcium absorption in the gut. However, including adequate amounts of calcium in the diet may help slow the rate of bone loss for all women.