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 ?
Maternal zinc supplementation and growth in Peruvian infants.
BACKGROUND Little is known about how maternal zinc intake influences growth in utero and in postnatal life in humans . OBJECTIVE We aim ed to assess the effect of maternal zinc supplementation during pregnancy on infant growth through age 1 y. DESIGN A double-blind , r and omized controlled trial of prenatal zinc supplementation was conducted from 1995 to 1997 in Lima , Peru . Women ( n = 1295 ) were enrolled at 15.6 + /- 4.6 wk gestation and assigned to receive daily supplements with zinc ( 15 mg Zn + 60 mg Fe + 250 microg folic acid ) or without zinc ( 60 Fe + 250 microg folic acid ) through pregnancy to 1 mo after delivery . At birth , 546 infants were followed for 12 mo to assess growth . Anthropometric measures of body size and composition were collected monthly , and morbidity and dietary intake surveillance was carried out weekly . RESULTS No differences in maternal socioeconomic characteristics by treatment group or follow-up period were found . Infants born to mothers prenatally supplemented with zinc had significantly ( P < 0.05 ) larger average growth measures beginning in month 4 and continuing through month 12 . In longitudinal regression modeling , prenatal zinc was associated with greater weight ( by 0.58 + /- 0.12 kg ; P < 0.001 ) , calf circumference ( by 1.01 + /- 0.21 cm ; P < 0.001 ) , chest circumference ( by 0.60 + /- 0.20 cm ; P = 0.002 ) , and calf muscle area ( by 35.78 + /- 14.75 mm(2 ) ; P = 0.01 ) after adjustment for a range of covariates . No effect was observed for linear growth . CONCLUSION Maternal zinc supplementation in this population was associated with offspring growth , which is suggestive of lean tissue mass accretion
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 ?