Zinc is one of the most important micronutrients in breast milk: Infants need large quantities of it during the first months of their lives to support growth, immune function and cognitive development. Yet despite zinc's importance, pediatricians aren't trained to detect the symptoms of its deficiency as of yet. We hope that will change in the near future.
Researchers in Penn State may have found a way to recognize women who are at risk of having low milk zinc levels. The team has identified a mutation in a particular zinc transporter -- called ZnT2 -- that cause defects in the milk-secreting mammary epithelial cells. This mutation causes women to have severe zinc deficiencies in their breast milk -- about a 75% reduction.
About 60% to 80% of women across the world are thought to be marginally zinc deficient just because of their diets per the Penn State research. In their experiment with mice, they found that it only takes a slight zinc deficiency to have profound consequences on mammary gland development and the ability to lactate.
Research found that the amount of zinc in your diet does not affect the amount of zinc that makes its way into breast milk. There is no evidence that milk zinc concentration can be affected by your diet so taking zinc supplements may not help. The research continues by suggesting that milk zinc levels may have more to do with whether or not you have genetic variation in ZnT2, or factors that affect the ability of ZnT2 to function properly.
According to the research, the lactation process may go haywire when a mother is overweight or obese.Two-thirds of women of reproductive age in the U.S. are overweight or obese and these women tend to have difficulties initiating and maintaining lactation.
Researchers are investigating the possibility that zinc and ZnT2 might have something to do with this.