We hypothesize , therefore , that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and , therefore , mitigate immediate detrimental effects due to a low zinc intake .
Zinc plays critical roles during embryogenesis , fetal growth , and milk secretion , which increase the zinc need for pregnancy and lactation .
Increased needs can be met by increasing the dietary zinc intake , along with making homeostatic adjustments in zinc utilization .
Potential homeostatic adjustments include changes in circulating zinc , increased zinc absorption , decreased zinc losses , and changes in whole body zinc kinetics .
Although severe zinc deficiency during pregnancy has devastating effects , systematic review s and meta- analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit .
The specific questions addressed are the following : How is zinc utilization altered during pregnancy and lactation ?
Are those homeostatic adjustments influenced by maternal zinc status , dietary zinc , or zinc supplementation ?
Low Zinc Intake During Exclusive Breast‐Feeding Does Not Impair Growth
We studied zinc nutrition in exclusively breast-fed infants whose growth deviated from the norm . Their number fell from 200 at birth to 116 at the age of 6 months and 36 at the age of 9 months . The mothers received 0 , 20 , or 40 mg Zn+ + as sulfate daily . Breast milk intake and concentrations of zinc in milk as well as in maternal and infant serum were measured . Individual zinc concentrations in milk showed channeling . The 20-mg supplement had no effect on the parameters measured . In contrast , 40 mg increased the maternal serum zinc concentration by 2 months and slowed the normal decline of milk zinc concentration by 6 months . Maternal supplementation had no effect on infant serum concen-trations ; they remained lower than adult levels throughout the 1st year of life .  Zinc intake was low ( about one-tenth of RDA ) , but it seemed to be adequate ; the serum concentrations of the infants were stable after the age of 2 months . Low zinc concentrations in serum were not associated with impaired growth . On the contrary , the infants with the highest rates of growth had the lowest zinc concentrations . The infant serum zinc concentrations were channeled , but they were also influenced by the zinc intake . Reference values for breast-fed infants are given
We hypothesize , therefore , that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and , therefore , mitigate immediate detrimental effects due to a low zinc intake .
Zinc plays critical roles during embryogenesis , fetal growth , and milk secretion , which increase the zinc need for pregnancy and lactation .
Increased needs can be met by increasing the dietary zinc intake , along with making homeostatic adjustments in zinc utilization .
Potential homeostatic adjustments include changes in circulating zinc , increased zinc absorption , decreased zinc losses , and changes in whole body zinc kinetics .
Although severe zinc deficiency during pregnancy has devastating effects , systematic review s and meta- analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit .
The specific questions addressed are the following : How is zinc utilization altered during pregnancy and lactation ?
Are those homeostatic adjustments influenced by maternal zinc status , dietary zinc , or zinc supplementation ?