Elevated parathyroid hormone-related peptide levels after human gestation: relationship to changes in bone and mineral metabolism.

PTH-related peptide (PTHrP) can be found in high concentrations in human breast milk and has been implicated in material calcium regulation postpartum. We studied the relationship of plasma PTHrP levels of serum markers of bone turnover and selective cancellous bone density in 35 women (age, 25 +/- 3 yr) 2-3 days postpartum and after 3 and 6 months of lactation. The mean postpartum plasma PTHrP levels measured by immunoradiometric assay was 2.