Maternal calcium metabolism during lactation

During lactation the main source of the breast-milk calcium seems to be mat ernal bone. The women who breast-fed, lost bone mineral content, which is r ecovered once breast-feeding ceased. Breast-milk calcium do. not depend on an increase in calcium intake by the lactating mother. Calcium demand durin g lactation is associated with adjustments in the calcium metabolism, such as a decrease in urinary calcium excretion and mobilization of calcium from maternal bone. The classical calciotropic hormones concentrations (PTH and 1,25-dihydroxyvitamin D) are not associated with bone turnover, markers or with changes in bone mineral content in the lactating women. However serum estradiol is strongly associated with-calcium balance, bone loss and calci um milk content.