Optimally, this is sustained in men until about age 60 and in women until menopause. Men and women over 65 experience increased bone loss, complicated by diets that tend to be calcium poor. Thus, building good calcium habits while we're young continues to serve our needs as we age. In women with active menstrual cycles, estrogen supports calcium absorption and inhibits excretion. 9 Menopause causes estrogen production to drop.
Less calcium is absorbed into the bones and more stays in the blood.
This causes vitamin D to become less active, which decreases calcium absorption and increases excretion. 10 Men experience similar consequences if testosterone levels drop. 11 Women also need more calcium during pregnancy and lactation. If a woman does not consume this extra calcium in addition to her own daily requirements, her reserves will become depleted and she may approach middle age and menopause with a bone disadvantage. Not all calcium is equal - at least in terms of absorption.