Zinc absorption and kinetics during pregnancy and lactation in Brazilian women. Zinc homeostasis during lactation in a population with a low zinc intake. Maternal zinc during oral iron supplementation in pregnancy: a preliminary study. Zinc supplementation during lactation: effects on maternal status and milk zinc concentrations. Adding zinc to prenatal iron and folate supplements improves maternal and neonatal zinc status in a Peruvian population. The effect of diet supplementation and addition of zinc in vitro on the growth-supporting property of amniotic fluid in African women. Maternal zinc supplementation and growth in Peruvian infants. Maternal supplemental and dietary zinc intake and the occurrence of neural tube defects in California. Randomized controlled trial of prenatal zinc supplementation and fetal bone growth. Prevalence of prenatal zinc deficiency and its association with socio-demographic, dietary and health care related factors in Rural Sidama, Southern Ethiopia: A cross-sectional study Prenatal iron supplements impair zinc absorption in pregnant Peruvian women. Randomized controlled trial of prenatal zinc supplementation and the development of fetal heart rate. Maternal micronutrient supplementation with zinc and β-carotene affects morbidity and immune function of infants during the first 6 months of life The effect of zinc supplementation on pregnancy outcome. Low Zinc Intake During Exclusive Breast‐Feeding Does Not Impair Growth Adding zinc to prenatal iron and folate tablets improves fetal neurobehavioral development. Plasma and erythrocyte zinc concentrations and their relationship to dietary zinc intake and zinc supplementation during pregnancy in low-income African-American women.
BACKGROUND Adjustments in zinc absorption and endogenous excretion maintain zinc homeostasis in nonpregnant adults fed low-zinc diets . The effects on zinc homeostasis of a low zinc intake during pregnancy and lactation have not been described in a longitudinal study . OBJECTIVE We examined longitudinal changes in fractional zinc absorption ( FZA ) and zinc kinetics in 10 healthy Brazilian women who habitually consumed a marginal zinc diet ( approximately 9 mg Zn/d ) . DESIGN  Zinc status was measured at 10 - 12 ( early pregnancy ; EP ) and 34 - 36 ( late pregnancy ; LP ) wk of pregnancy and at 7 - 8 wk after delivery ( early lactation ; EL ) . Zinc kinetics and FZA were studied by using stable isotopic tracers . RESULTS Zinc intake averaged 9 + /- 3 mg/d throughout the study . FZA increased from 29 + /- 6 % at EP to 43 + /- 10 % at LP and to 39 + /- 13 % at EL ( P < 0.05 ) . FZA was inversely related to plasma zinc at EL ( r = -0.73 , P = 0.02 ) and LP ( r = -0.72 , P = 0.07 ) . Plasma zinc mass was 23 % greater at LP than at EP or EL ( P < 0.05 ) . The amount of zinc ( mg/d ) that fluxed between plasma and the most-rapidly-turning-over extravascular pool was 53 % greater at LP than at EP or EL ( P < 0.05 ) . The zinc flux between plasma and the less-rapidly-turning-over zinc pool at EL was 27 % greater than that at EP or LP , but this difference was not significant . CONCLUSIONS FZA increased significantly in women with marginal zinc intakes during pregnancy and lactation ; the increase was higher in women with low plasma zinc . Plasma zinc was distributed into a different exchangeable pool at LP than at EL BACKGROUND There is a major increase in endogenous zinc excretion , specifically via the mammary gl and , in early human lactation . Whereas fractional absorption of dietary zinc has been reported to increase in early human lactation , it is not known to what extent adaptive mechanisms may maintain zinc homeostasis , especially when dietary zinc intake is relatively low . OBJECTIVE The objective of this study was to quantitate major variables of zinc homeostasis during early lactation in subjects from a population whose habitual dietary zinc intake is low . DESIGN We studied 18 free-living lactating women from a rural community of northeast China whose infants were exclusively breast-fed .  The subjects were studied at approximately 2 mo of lactation with use of stable isotopes of zinc and metabolic collection techniques .  Milk volume was measured with use of a deuterium enrichment method . RESULTS The mean ( + /-SD ) secretion of zinc in milk was 2.01 + /- 0.97 mg/d , the intake of zinc was 7.64 + /- 1.61 mg/d , and the fractional absorption of zinc was 0.53 + /- 0.09 , for a total daily zinc absorption of 4.00 + /- 0.71 mg/d . Endogenous zinc excretion in urine and feces was 0.30 + /- 0.10 and 1.66 + /- 0.97 mg/d , respectively . CONCLUSIONS Zinc balance , including zinc secreted in breast milk , was maintained at approximately 2 mo of lactation in women whose habitual diet was low in zinc . Homeostasis was achieved by high fractional absorption of zinc and intestinal conservation of endogenous fecal zinc 1 . To investigate the possible effect of iron ingestion on maternal zinc status , one group of women was given 94 mg of iron per day as ferrous sulphate with multivitamins during the second and third trimesters of their pregnancies and another , control , group was given a placebo of multivitamins without iron . 2 . The subjects given iron developed significantly lower plasma zinc concentrations than those in the control group . This effect on zinc was maximal by 6 weeks , whilst that on maternal iron status was slower . 3 . There was no parallel decrease of zinc concentration in maternal mixed leucocytes , or of plasma heatlabile alkaline phosphatase activity , suggesting that there was a redistribution of zinc between plasma and tissues . 4 . The results indicate that iron supplementation during pregnancy alters the disposition of zinc in the mother The effects of a zinc supplement on maternal zinc status and milk zinc concentrations through > or = 7 mo of lactation were examined . Seventy-one lactating women received either a daily 15-mg zinc supplement ( ZS , n = 40 ) or placebo ( NZS , n = 31 ) started by 2 wk postpartum in a double-blind , r and omized design . Overall mean zinc intakes were 13.0 + /- 3.4 mg/d for the NZS group and 25.7 + /- 3.9 mg/d ( including supplement ) for the ZS group . Plasma zinc concentrations of the ZS group were significantly higher than those of the NZS group ( P = 0.05 ) . Milk zinc concentrations declined significantly over the course of the study for all subjects but were not affected by zinc supplementation . The mean dietary zinc intake observed in the nonsupplemented group was adequate to maintain normal maternal zinc status and milk zinc concentrations through > or = 7 mo lactation . Similar controlled intervention trials in less well-nourished population s will be required to assess the impact of lower zinc intakes on milk zinc concentrations BACKGROUND Maternal zinc deficiency during pregnancy may be widespread among women in developing countries , but few data are available on whether prenatal zinc supplementation improves maternal and neonatal zinc status . OBJECTIVE We studied whether maternal zinc supplementation improved the zinc status of mothers and neonates participating in a supplementation trial in a shantytown in Lima , Peru . DESIGN Beginning at gestation week 10 - 24 , 1295 mothers were r and omly assigned to receive prenatal supplements containing 60 mg Fe and 250 microg folate , with or without 15 mg Zn .  Venous blood and urine sample s were collected at enrollment , at gestation week 28 - 30 , and at gestation week 37 - 38 . At birth , a sample of cord vein blood was collected . We measured serum zinc concentrations in 538 women , urinary zinc concentrations in 521 women , and cord zinc concentrations in 252 neonates . RESULTS At 28 - 30 and 37 - 38 wk , mothers receiving zinc supplements had higher serum zinc concentrations than mothers who did not receive zinc ( 8.8 + /- 1.9 compared with 8.4 + /- 1.5 micromol/L and 8.6 + /- 1.5 compared with 8.3 + /- 1.4 micromol/L , respectively ) . Urinary zinc concentrations were also higher in mothers who received supplemental zinc ( P < 0.05 ) . After adjustment for covariates and confounding factors , neonates of mothers receiving zinc supplements had higher cord zinc concentrations than neonates of mothers who did not receive zinc ( 12.7 + /- 2.3 compared with 12.1 + /- 2.1 micromol/L ) . Despite supplementation , maternal and neonatal zinc concentrations remained lower than values reported for well-nourished population s. CONCLUSION Adding zinc to prenatal iron and folate tablets improved maternal and neonatal zinc status , but higher doses of zinc are likely needed to further improve maternal and neonatal zinc status in this population The effect of diet supplementation throughout pregnancy on third-trimester amniotic fluid growth-supporting activity ( GSP ) was studied in 100 African women ; 32 were given zinc supplementation ,  22  each animal and vegetable supplements , respectively  , and 24 served as  control subjects .  No difference in GSP was noted in any of the four groups , the majority of fluids ( 65 % ) being noninhibitory . Zinc levels in fluids from African women were much lower than those described for other population groups at corresponding periods of gestation . Although zinc levels in liquor rose following dietary zinc supplementation , these remained lower than values described in white patients . In vitro addition of zinc ( up to 153 mu moles per liter final concentration ) to 17 noninhibitory African liquors result ed in these fluids becoming inhibitory 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 The authors investigated the association between maternal preconceptional  supplemental and dietary zinc intake and risk of  neural tube defects ( NTDs ) in a population -based case-control study conducted between 1989 and 1991 in California . Cases were 430 NTD-affected fetuses/infants , and controls were 429 r and omly selected non-malformed infants . Mothers reported their preconceptional use of vitamin , mineral , and food supplements , and completed a 98-item food frequency question naire . Increased total preconceptional zinc intake was associated with a reduced risk for NTDs ( quintile 5 vs. quintile 1 , odds ratio ( OR ) = 0.65 , 95 % confidence interval ( CI ) 0.43 , 0.99 ) . Phytate intake , a constituent of the diet known to impede zinc absorption , appeared to modify the zinc - NTD association . In addition , increased servings of animal products , the most bioavailable food source of zinc , was associated with a reduced risk for NTDs ( quintile 5 vs. quintile 1 , OR = 0.49 , 95 % CI 0.32 , 0.76 ) . Risk estimates for  zinc intake were changed little after controlling for multiple sociodemographic factors and total folate intake , but were attenuated after controlling for nutrients highly correlated with dietary sources of zinc , such as protein . In sum , the analyses indicate that risk of NTDs in infants and fetuses decreased with increasing maternal preconceptional zinc intake . However , it remains unclear whether increased zinc intake , or another nutrient or combination of nutrients highly correlated with zinc intake in the diet , is causally associated with reduced NTD risk BACKGROUND Maternal zinc deficiency is relatively common in developing countries , but its consequences for fetal growth are not established . OBJECTIVE The goal was to examine whether improvement in maternal gestational zinc status is positively associated with fetal growth as assessed by ultrasonography . DESIGN We conducted a double-masked , r and omized trial among 242 pregnant Peruvian women in an impoverished shantytown in Lima , Peru . At 10 - 16 wk of gestation , the women were r and omly assigned to receive daily supplements containing 60 mg Fe and 250 microg folic acid , with or without 25 mg Zn . We measured fetal head circumference , biparietal diameter , abdominal circumference , and femur diaphysis length at 20 , 24 , 28 , 32 , 36 , and 38 wk of gestation . Fetal measures were analyzed longitudinally to evaluate differences in trends of fetal growth by supplement type , and within-subject correlations were taken into account . RESULTS Femur diaphysis length was greater in fetuses whose mothers received zinc supplements ( P < 0.05 ) , and the difference tended to increase with gestational age . No significant differences by supplement type were observed for the other anatomical sites measured . CONCLUSIONS The observed positive effect of prenatal zinc on fetal femur diaphysis length is consistent with the results of experimental studies in animals and in vitro . The supplementation effect represents an upward shift in mean femur diaphysis length at term of about one-quarter of the reference SD . These findings suggest the potential importance of maternal zinc status for fetal bone growth in humans and illustrate the value of ultrasonography for evaluating the effect of prenatal nutritional interventions on components of fetal growth Background Several studies witnessed that prenatal zinc deficiency ( ZD ) predisposes to diverse pregnancy complications . However , scientific evidence s on the determinants of prenatal ZD are scanty and inconclusive . The purpose of the present study was to assess the prevalence and determinants of prenatal ZD in Sidama zone , Southern Ethiopia . Methods A community based , cross-sectional study was conducted in Sidama zone in January and February 2011 . R and omly selected 700 pregnant women were included in the study . Data on potential determinants of ZD were gathered using a structured question naire . Serum zinc concentration  was measured using Atomic Absorption Spectrometry . Statistical analysis was done using logistic regression and linear regression . Results The mean serum zinc concentration was 52.4 ( + /-9.9 ) μg/dl ( 95 % CI : 51.6 - 53.1 μg/dl ) . About 53.0 % ( 95 % CI : 49.3 - 56.7 % ) of the subjects were zinc deficient . The majority of the explained variability of serum zinc was due to dietary factors like household food insecurity level , dietary diversity and consumption of animal source foods . The risk of ZD was 1.65 ( 95 % CI : 1.02 - 2.67 ) times higher among women from maize staple diet category compared to  Enset staple diet category . Compared to pregnant women aged 15 - 24 years , those aged 25 - 34 and 35 - 49 years had 1.57 ( 95 % CI : 1.04 - 2.34 ) and 2.18 ( 95 % CI : 1.25 - 3.63 ) times higher risk of ZD , respectively . Women devoid of self income had 1.74 ( 95 % CI : 1.11 - 2.74 ) time increased risk than their counterparts . Maternal education was positively associated to zinc status . Gr and multiparas were 1.74 ( 95 % CI : 1.09 - 3.23 ) times more likely to be zinc deficient than nulliparas . Frequency of coffee intake was negatively association to serum zinc level . Positive association was noted between serum zinc and hemoglobin concentrations . Altitude , history of iron supplementation , maternal workload , physical access to health service , antenatal care and nutrition education were not associated to zinc status . Conclusion ZD is of public health concern in the area . The problem must be combated through a combination of short , medium and long-term strategies . This includes the use of household based phytate reduction food processing techniques , agricultural based approaches and livelihood promotion strategies Prenatal iron supplements may adversely influence zinc absorption during pregnancy . To examine the impact of prenatal iron supplements on supplemental zinc absorption , fractional zinc absorption was measured in 47 pregnant Peruvian women during the third trimester of pregnancy ( 33 + /- 1 wk gestation ) . Of these 47 women , 30 received daily prenatal supplements  from wk 10 - 24 of pregnancy until delivery . Supplements contained 60 mg of Fe and 250 microg of folate without [ iron group ( Fe ) , n = 16 ] or with [ iron and zinc supplemented group ( Fe + Zn ) , n = 14 ] 15 mg of Zn . The remaining 17 women [ unsupplemented control group ( C ) ] received no prenatal supplementation .  Zinc concentrations were measured in plasma , urine and cord blood and percentage zinc absorption was determined following dosing with oral ( (67)Zn ) and intravenous ( (70)Zn ) stable zinc isotopes . Percentage zinc absorption was significantly lower than controls in fasting women receiving iron- containing prenatal supplements ( 20.5 + /- 6.4 vs. 20.2 + /- 4.6 vs. 47.0 + /- 12.6 % , Fe , Fe + Zn and C groups , respectively , P : < 0.0001 , n = 40 ) . Plasma zinc concentrations were also significantly lower in the Fe group compared to the C group ( 8.2 + /- 2.2 vs. 9.2 + /- 2.2 vs. 10.9 + /- 1 . 8 micromol/L , Fe , Fe + Zn and C groups , respectively , P : = 0.002 ) , and cord zinc concentrations were significantly related to maternal plasma Zn levels ( y = 6.383 + 0.555x , r = 0.486 , P : = 0.002 ) . The inclusion of zinc in prenatal supplements may reduce the potential for iron supplements to adversely influence zinc status in population s at risk for deficiency of both these nutrients OBJECTIVES This study was undertaken to evaluate whether prenatal zinc supplementation affects maturation of fetal cardiac patterns . STUDY DESIGN A r and omized double-blind controlled trial among 242 low-income Peruvian women was performed . Beginning at 10 to 16 weeks ' gestation , women received supplements containing 60 mg iron , 250 microg folic acid with or without 25 mg zinc .  Fetal heart rate ( mean FHR , variability [ HRV ] , number of accelerations ) and movements ( number and amplitude of movement bouts , time spent moving ) were electronically monitored monthly from 20 weeks ' gestation . Developmental trends were evaluated by supplement type among 195 women who completed the trial and had no serious complications of pregnancy . RESULTS Zinc supplementation was associated with lower FHR , greater number of accelerations , and greater HRV . Supplementation effects on HRV and accelerations were more pronounced after 28 weeks ' gestation . No differences in motor activity were observed . CONCLUSION Prenatal supplementation of zinc-deficient mothers may be beneficial to fetal neurobehavioral development Background / Objectives : Micronutrient deficiencies are prevalent worldwide , and a major cause of infant death . Supplementation with multiple micronutrients during pregnancy might improve micronutrient status of the newborn , thereby reducing morbidity and death . Moreover , maternal supplementation might affect the newborn 's immune development . Therefore , this study investigated the effects of maternal zinc and β-carotene supplementation on the  infant  's morbidity and immune function during the first 6 months of life . Subjects/ Methods : Mothers were supplemented during pregnancy  with β-carotene and /or zinc , in addition to iron and folic acid , in a r and omized , double-blind controlled trial . Newborn infants ( n=136 ) were followed up for 6 months . Results : Infants born from mothers receiving zinc during pregnancy had significantly fewer episodes of diarrhoea than infants born from mothers not receiving zinc ( 0.2 and 0.4 , respectively ) , but more episodes of cough ( 1.3 and 0.9 respectively ) during the first 6 months . Maternal β-carotene supplementation had no effect on infants ’ morbidity . Cytokine production in the newborns was affected by maternal zinc and β-carotene supplementation , with zinc supplementation giving higher interleukin-6 production ( 16 % higher ) , and β-carotene supplementation leading to lower interferon-γ production ( 36 % lower ) . Conclusions : This study shows that maternal supplementation with zinc and β-carotene affected the newborn 's immune development in specific ways , but only maternal zinc supplementation significantly affected morbidity in the infants . Addition of zinc to routine iron and folic acid supplements for pregnant women could be an effective way to reduce diarrhoeal disease during the first 6 months of life , albeit at the expense of more episodes of cough OBJECTIVE To evaluate whether zinc supplementation during pregnancy is associated with an increase in birth weight . DESIGN A r and omized double-blind placebo-controlled trial . SETTING Outpatient clinic and delivery service at the University of Alabama at Birmingham . PATIENTS Five hundred eighty medically indigent but otherwise healthy African-American pregnant women with plasma zinc levels below the median at enrollment in prenatal care , r and omized at 19 weeks ' gestational age . Women were subdivided by the population median body mass index of 26 kg/m2 into two groups for additional analyses . INTERVENTION Women who were taking a non-zinc-containing prenatal multivitamin/mineral tablet  were r and omized to receive either a daily dose of 25 mg of zinc or a placebo until delivery . MAIN OUTCOME MEASURES Birth weight , gestational age at birth , and head circumference at birth . RESULTS In all women , infants in the zinc supplement group had a significantly greater birth weight ( 126 g , P = .03 ) and head circumference ( 0.4 cm , P = .02 ) than infants in the placebo group . In women with a body mass index less than 26 kg/m2 , zinc supplementation was associated with a 248-g higher infant birth weight ( P = .005 ) and a 0.7-cm larger infant head circumference ( P = .007 ) . Plasma zinc concentrations were significantly higher in the zinc supplement group . CONCLUSIONS Daily zinc supplementation in women with relatively low plasma zinc concentrations in early pregnancy is associated with greater infant birth weights and head circumferences , with the effect occurring predominantly in women with a body mass index less than 26 kg/m2 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 OBJECTIVE Our objective was to examine whether improvement in maternal zinc status during pregnancy is positively associated with fetal neurobehavioral development  in a Peruvian population . STUDY DESIGN We electronically monitored , at 32 and 36 weeks ' gestation , 55 fetuses whose mothers were r and omly assigned to receive , during pregnancy , a daily supplement containing 60 mg iron and 250 microg folate , with or without 15 mg zinc .  Fetal heart rate and movement patterns were quantified in 55 and 34 fetuses , respectively , as indexes of neurobehavioral development . RESULTS Fetuses of mothers who received zinc supplementation showed fewer episodes of minimal fetal heart rate variability , increased fetal heart rate range , an increased number of accelerations , an increased number of movement bouts , an increased amount of time spent moving , and an increased number of large movements . Differences by supplementation type increased with gestational age and were statistically significant at 36 weeks ' gestation ( P < .05 ) . CONCLUSION Improving maternal zinc status through prenatal supplementation may improve fetal neurobehavioral development OBJECTIVE To evaluate the effects of usual dietary intake of zinc and of zinc supplementation during pregnancy on plasma and erythrocyte zinc concentrations . DESIGN A r and omized , double-blind , placebo-controlled trial . SUBJECTS Low-income African-American women ( n = 580 ) assigned r and omly to groups at 19 weeks of gestation . INTERVENTION A daily dose of zinc ( 25 mg ) or a placebo until delivery . MAIN OUTCOME MEASURES Plasma , erythrocyte , and dietary zinc levels . STATISTICAL ANALYSES Multiple regression and repeated measures analysis of variance . RESULTS In both the placebo and the supplemented groups , when all subjects were grouped by usual dietary zinc intake above or below the median ( 12 mg/day ) , results were the same : Women with high dietary zinc intake had higher erythrocyte zinc levels at the time of r and omization and at all subsequent measurements during pregnancy than those who had low dietary zinc intake ( P < or = .06 ; difference not significant for zinc-supplemented group ) ; no difference was observed for plasma zinc levels . On the other h and , when the subjects were stratified at the median by total daily zinc intake ( usual dietary zinc + 25 mg zinc supplement ) during pregnancy , a significant difference in plasma zinc levels ( P < .005 ) was found between women with high total zinc intake ( mean = 38 mg/day ) and low total intake ( mean = 13 mg/day ) at 26 , 32 , and 38 weeks of gestation ; however , no such differences were found in erythrocyte zinc levels . APPLICATIONS These results should help dietitians and other health professionals better underst and the expected changes in plasma and erythrocyte zinc levels during pregnancy , and the relationship between dietary and supplemental zinc and zinc nutriture
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 ?