Maternal bone density decreases after childbirth, but only among women who lactate for at least four months. The lactation period is unrelated to vitamin D status. A PhD thesis at Sahlgrenska Academy has explored the issue.
The most important role of vitamin D is to help maintain calcium homeostasis in the body. According to some hypotheses, there is a correlation between maternal vitamin D status and bone density during pregnancy and lactation. A recently completed PhD thesis at Sahlgrenska Academy, University of Gothenburg, identified an association between lactation period and bone density, though unrelated to vitamin D status.
