The ins and outs of mammary gland calcium and zinc transport: A brief review

Milk is an excellent source of all macrominerals and trace elements, which are essential for proper function of a wide variety of vital processes. The concentrations of minerals in milk are influenced by numerous factors, including stage of lactation, time of day, nutritional and health status of the mother, as well as maternal genotype and environmental exposures. Additionally, tight regulation of mineral transport within the secretory mammary epithelial cell itself is critical for the production and secretion of milk. In this brief review, we focus on the current understanding of how the essential divalent cations calcium (Ca) and zinc (Zn) are transported in the mammary gland (MG) with a focus on molecular regulation and the consequence of genotype. A deeper grasp of mechanisms and factors affecting Ca and Zn transport in the MG is important to understanding milk production, mineral output, and MG health to inform intervention design and novel diagnostic and therapeutic strategies in production animals and humans.