Digging deeper into the mother-offspring transfer of selenium through human breast milk

Selenoprotein P contains most of the selenium in plasma and favours selenium retention in the brain over other organs. Recently, the presence of selenoprotein P in human breast milk has been demonstrated, filling the gap around the mother-offspring transfer of selenium during lactation and through cord serum. In this work, selenometabolites and selenoproteins have been accurately determined in human breast milk and cord and maternal sera. Using a heteroatom tagged proteomic method, twenty mother-child couples were analysed. The mean total concentration in maternal serum was 90 +/- 10 ng Se g(-1) (1.33 and 1.52-fold higher than that in cord serum and human breast milk, respectively). The concentration of selenoprotein P (ng Se g(-1)) follows the order: maternal serum (57.1 +/- 8.8) > cord serum (33.6 +/- 4.2) > breast milk (18.8 +/- 5.1). Glutathione peroxidase was mainly transferred by breast milk, selenometabolites were transferred by breast milk and cord serum and selenocystamine was only present in breast milk.

Automated summary

Selenoprotein P is found in human breast milk and plays a crucial role in selenium transfer during lactation. Concentration of selenium in maternal serum is higher than cord serum and breast milk, with glutathione peroxidase mainly transferred through breast milk.