Global and regional child mortality and burden of disease attributable to zinc deficiency Effect on longitudinal growth and anemia of zinc or multiple micronutrients added to vitamin A: a randomized controlled trial in children aged 6-24 months Zinc supplementation and stunted infants in Ethiopia: a randomised controlled trial Effect of zinc supplementation on growth in West African children: a randomized double-blind placebo-controlled trial in rural Burkina Faso. Effects of Zinc Supplementation on Physical Growth in 2–5-Year-Old Children The impact of zinc supplementation on growth and body composition: A randomized, controlled trial among rural Zimbabwean schoolchildren Effect of zinc supplementation on growth and body composition in children with sickle cell disease. Magnitude of Zinc Deficiency amongst Under Five Children in India Impact of zinc supplementation on subsequent growth and morbidity in Bangladeshi children with acute diarrhoea Effect of micronutrient supplementation on diarrhoeal disease among stunted children in rural South Africa Zinc supplementation improves the growth of stunted rural Guatemalan infants. Linear growth of low income preschool children receiving a zinc supplement. Zinc Therapy for Diarrhoea Improves Growth Among Bangladeshi Infants 6 to 11 Months of Age Linear Growth and Zinc Supplementation in Children with Short Stature Zinc supplementation for four months does not affect growth in young north Indian children. Zinc supplementation improved length growth only in anemic infants in a multi-country trial of iron and zinc supplementation in South-East Asia. Effect of daily zinc supplementation on child mortality in southern Nepal: a community-based, cluster randomised, placebo-controlled trial
Background / Objectives : Zinc is an essential micronutrient and deficiency can lead to an increased risk for infectious diseases and growth retardation among children under 5 years of age . We aim ed to estimate disease-specific and all-cause mortality attributable to zinc deficiency . Subject/ Methods : We estimated the prevalence of zinc deficiency in Latin America , Africa and Asia , where based on zinc availability in the diet and childhood stunting rates , zinc deficiency is widespread . The relative risks of death among zinc-deficient children for diarrhea , malaria and pneumonia were estimated from r and omized controlled trials . We used the comparative risk assessment methods to calculate deaths and burden of disease ( measured in disability-adjusted life years , DALYs ) from each of these three diseases attributable to zinc deficiency in these regions . Results : Zinc deficiency was responsible for 453 207 deaths ( 4.4 % of childhood deaths ) , and 1.2 % of the burden of disease ( 3.8 % among children between 6 months and 5 years ) in these three regions in 2004 . Of these deaths , 260 502 were in Africa , 182 546 in Asia and 10 159 in Latin America . Zinc deficiency accounted for 14.4 % of diarrhea deaths , 10.4 % of malaria deaths and 6.7 % of pneumonia deaths among children between 6 months and 5 years of age . Conclusions : Zinc deficiency contributes to substantial morbidity and mortality , especially from diarrhea .  Zinc supplementation provided as an adjunct treatment for diarrhea may be the best way to target children most at risk of deficiency Background The benefits of zinc or multiple micronutrient supplementations in African children are uncertain . African children may differ from other population s of children in developing countries because of differences in the prevalence of zinc deficiency , low birth weight and preterm delivery , recurrent or chronic infections such as HIV , or the quality of complementary diets and genetic polymorphisms affecting iron metabolism . The aim of this study was to ascertain whether adding zinc or multiple micronutrients to vitamin A supplementation improves longitudinal growth or reduces prevalence of anemia in children aged 6 - 24 months . Methods R and omized , controlled double-blinded trial of prophylactic micronutrient supplementation to children aged 6 - 24 months . Children in three cohorts - 32 HIV-infected children , 154 HIV-uninfected children born to HIV-infected mothers , and 187 uninfected children born to HIV-uninfected mothers - were separately r and omly assigned to receive daily vitamin A ( VA ) [ n = 124 ] , vitamin A plus zinc ( VAZ ) [ n = 123 ] , or multiple micronutrients that included vitamin A and zinc ( MM ) [ n = 126 ] . Results Among all children there were no significant differences between intervention arms in length-for-age Z scores ( LAZ ) changes over 18 months . Among stunted children ( LAZ below -2 ) [ n = 62 ] , those receiving MM had a 0.7 Z-score improvement in LAZ versus declines of 0.3 in VAZ and 0.2 in VA ( P = 0.029 when comparing effects of treatment over time ) . In the 154 HIV-uninfected children , MM ameliorated the effect of repeated diarrhea on growth . Among those experiencing more than six episodes , those receiving MM had no decline in LAZ compared to 0.5 and 0.6 Z-score declines in children receiving VAZ and VA respectively ( P = 0.06 for treatment by time interaction ) . After 12 months , there was 24 % reduction in proportion of children with anemia ( hemoglobin below 11 g/dL ) in MM arm ( P = 0.001 ) , 11 % in VAZ ( P = 0.131 ) and 18 % in VA ( P = 0.019 ) . Although the within arm changes were significant ; the between-group differences were not significant . Conclusions Daily multiple micronutrient supplementation combined with vitamin A was beneficial in improving growth among children with stunting , compared to vitamin A alone or to vitamin A plus zinc . Effects on anemia require further study .Trial registration This study is registered with Clinical Trials.gov , number .NCT00156832 BACKGROUND Stunting is highly prevalent in Ethiopia and many other developing countries but the reason for it is poorly understood . Zinc is essential for growth but diets in such countries often do not contain zinc in sufficient quantity or of sufficient bioavailability . Thus zinc deficiency may play a major role in stunting . The aim of the study was to investigate whether the low rate of linear growth of apparently healthy breastfed infants in a rural village in Ethiopia could be improved by zinc supplementation . METHODS A r and omised , double-blind , placebo-controlled trial was done on apparently healthy breastfed infants aged 6 - 12 months . 100 non-stunted ( length-for-age , Z score < -2 ) were matched for age and sex with 100 r and omly selected stunted ( > -2 ) infants . Infants , both stunted and non stunted , were matched by sex , age ( within 2 months ) and recumbent length ( within 3 cm ) for r and om assignment , to receive a zinc supplement ( 10 mg zinc per day , as zinc sulphate ) or placebo , 6 days a week for 6 months . Anthropometric measurements were taken monthly , data on illness and appetite were collected daily , and sample s of serum and hair were taken at the end of the intervention for the analysis of zinc . FINDINGS The length of stunted infants increased significantly more ( p<0.001 ) when supplemented with zinc ( 7.0 cm [ SE 1.1 ] ) than with placebo ( 2.8 cm [ 0.9 ] ) ; and the effect was greater ( p<0.01 ) than in non-stunted infants ( 6.6 [ 0.9 ] vs 5.0 [ 0.8 ] cm for the zinc and placebo groups respectively , p<0.01 ) . Zinc supplementation also increased the weight of stunted children ( 1.73 [ 0.39 ] vs 0.95 [ 0.39 ] kg for the corresponding placebo group , p<0.001 ) and of non-stunted children ( 1.19 [ 0.39 ] vs 1.02 [ 0.32 ] kg for the corresponding placebo group , p<0.05 ) . Zinc supplementation result ed in a markedly lower incidence of anorexia and morbidity from cough , diarrhoea , fever , and vomiting in the stunted children . The total number of these conditions per child was 1.56 and 1.11 in the stunted and non-stunted zinc supplemented children versus 3.38 and 1.64 in the stunted and non-stunted placebo-treated children , respectively . At the end of the intervention period , the concentrations of zinc in serum and hair of stunted infants , who had not been supplemented with zinc , were lower than the respective concentrations of zinc in serum and hair of their non-stunted counterparts . INTERPRETATION Combating zinc deficiency can increase the growth rate of stunted children  to that of non-stunted infants in rural Ethiopia . This would appear to be due , at least in part , to reduction in morbidity from infection and increased appetite OBJECTIVE To analyse the effects of zinc supplementation on growth parameters in a representative sample of young children in rural Burkina Faso . Design R and omized , double-blind , placebo-controlled efficacy trial . Setting Eighteen villages in rural northwestern Burkina Faso . Subjects In all , 709 children aged 6 - 31 months were enrolled ; 685 completed the trial . Intervention Supplementation with zinc ( 12.5 mg zinc sulphate ) or placebo daily for 6 days a week for 6 months . Outcomes Weight , length/height , mid-arm circumference , and serum zinc . RESULTS In a representative sub sample of study children , 72 % were zinc-deficient at baseline . After supplementation , serum zinc increased in zinc-supplemented but not in control children of the sub sample . No significant differences between groups were observed during follow-up regarding length/height , weight , mid-arm circumference , and z scores for height-for-age , weight-for-age , and weight-for-height . CONCLUSIONS We conclude that zinc supplementation does not have an effect of public health importance on growth in West African population s of young children with a high prevalence of malnutrition . Multinutrient interventions are likely to be more effective Physical growth disorders in under 5-year-old children are a common health problem in many countries including Iran . The aim of this study was to determine effects of supplemental zinc on physical growth in preschool children with retarded linear growth .  This study was a community-based r and omized controlled trial on 2–5-year-old children with height-for-age below 25th percentile of National Center for Health Statistics growth chart . Ninety children were r and omly assigned in  zinc  group ( ZG ) or placebo group ( PG ) . After 6 months of zinc or placebo supplementation , we followed up the children for another 6 months . Anthropometric indicators were measured before the intervention and then monthly for 11 months . Forty children in ZG and 45 in PG concluded the study . Zinc supplementation increased weight gain in boys ( P = 0.04 ) and girls ( P = 0.05 ) compared to placebo but had no significant effect on mid-upper arm circumference increment in either sexes . The most significant ( P = 0.001 ) effect of Zinc supplementation was seen in boys ’ height increment at the end of follow-up period . Stunted growth rate in ZG changed significantly ( P = 0.01 ) from 26.7 % to 2.5 % throughout the study . This study showed that daily supplementation of 5 mg elemental zinc for 6 months improves physical growth in terms of height increment and weight gain in children with undesirable linear growth , especially in boys OBJECTIVES : To assess the effect of zinc supplementation on growth and body composition among schoolchildren . DESIGN : R and omized , double-blind , placebo-controlled trial . SETTING AND SUBJECTS : 313 rural Zimbabwean schoolchildren ( 144 boys and 169 girls ) , 11–17 y ) . INTERVENTIONS : Supplementation with zinc ( 30 or 50 mg ) or placebo on schooldays for 12 months . Due to drought , a food programme was in operation during the last eight months of the study .VARIABLES : Weight , height , upper arm circumference , triceps skinfold thickness , and weight-for-age , height-for-age , weight-for-height , arm muscle-area-for-age and arm fat-area-for-age Z-scores . RESULTS : Significant effects on weight gain ( 0.51 vs 0.14 kg , P=0.01 ) , weight-for-age Z ( −0.08 vs −0.14 , P=0.01 ) and arm muscle area-for-age Z-score ( 0.10 vs 0.01 , P=0.03 ) were seen over the first three months , whereas no effects were seen over the full 12 months . CONCLUSIONS : Zinc deficiency impairing lean body mass and weight gain was documented . However , the effect of zinc seen over the first three months vanished during the last nine months when the food programme was in operation . Zinc deficiency may have persisted , but another nutrient may have become growth limiting during the last nine months . SPONSORSHIP : Danish International Development Assistance BACKGROUND Poor growth and delayed maturation in children with sickle cell disease ( SCD ) may be due , in part , to mild zinc deficiency . OBJECTIVE The objective was to determine the effects of zinc supplementation on growth and body composition in children with SCD . DESIGN Forty-two prepubertal children ( 20 girls and 22 boys ) aged 4 - 10 y with SCD-SS were r and omly assigned to receive 10 mg elemental Zn/d in cherry syrup ( zinc group ) or cherry syrup alone ( control group ) . The 2 groups were stratified by sex and initial height status . Dietary intakes were evaluated and anthropometric , high-precision knee-height , and plasma zinc measurements were made at baseline and at 3 , 6 , and 12 mo . Body composition was determined every 6 mo with dual-energy X-ray absorptiometry , and z scores for anthropometric variables were computed from national reference data . Longitudinal-mixed-effects analysis was used to test for differences between the groups over the 12-mo observation period . RESULTS Thirty-eight children completed the study . No significant differences were observed at baseline . After 12 mo , the zinc group had significantly greater mean ( + /- SE ) increases in height ( 0.66 + /- 0.29 cm/y ) , sitting height ( 0.97 + /- 0.40 cm/y ) , knee height ( 3.8 + /- 1.2 mm/y ) , and arm circumference z scores ( 0.27 + /- 0.12 cm/y ) . Height-for-age and weight-for-age z scores decreased significantly by 0.11 + /- 0.04 and 0.13 + /- 0.05 , respectively , in the control group but did not change significantly in the zinc group . CONCLUSIONS Prepubertal children with SCD-SS may have zinc deficiency and may benefit from zinc supplementation to improve linear growth and weight gain Objective To estimate the prevalence of serum zinc deficiency in children of 6 months to 60 months of age . Methods A community based cross-sectional study was conducted to collect the data to establish the prevalence of  zinc deficiency in children in 6–60 months of age in five states namely , Uttar Pradesh(Northern region ) , Karnataka ( Southern region ) , Orissa ( Eastern region ) , Gujarat ( Western region ) and Madhya Pradesh ( Central region ) of the country . In each state , all the districts with ICDS scheme were enlisted and one district was selected with the help of R and om number table ( RNT ) . In each district , all the ICDS projects were selected and one ICDS project was selected with help of RNT . In the selected ICDS project , a cluster 5 Anganwadi centres ( AWC ) were selected . From the selected AWCs , three hundred children in the age group of 6–60 months were selected for the detailed study . A total of 1,655 subjects ( 836 males and 819 females ) were included . The blood sample s were collected from each child . The serum zinc estimation was done by atomic absorption spectrophotometer . Results The overall prevalence of zinc deficiency in five states was 43.8 % . The prevalence of zinc deficiency was highest in Orissa ( 51.3 % ) , followed by Uttar Pradesh ( 48.1 % ) , Gujarat ( 44.2 % ) , Madhya Pradesh ( 38.9 % ) and Karnataka ( 36.2 % ) . Conclusions The present study revealed a high prevalence of zinc deficiency in children belonging to Low Socio-economic Index ( LSI ) in Objective : To assess the impact of zinc supplementation during acute diarrhoea on subsequent growth and morbidity in malnourished young children . Design : Double blind r and omized controlled clinical trial Setting : International Centre for Diarrhoeal Disease Research , Bangladesh . Subjects : Sixty-five children aged 3–24 months with acute diarrhoea for less than 3 d . Intervention : Either elemental zinc ( 20 mg/d ) in a multivitamin syrup or multivitamin syrup alone divided in three divided daily doses for a period of two weeks . Children were followed up weekly at home to assess subsequent growth and morbidity for a period of eight weeks . Main outcome measures : Gain in length and body weight and reduction in diarrhoea and respiratory tract infection . Results : During the follow-up , zinc supplemented children showed significantly greater cumulative length gain ( 18.9 mm vs 14.5 mm , P<0.03 ) and comparable body weight gain than the children of the control group . Subsequent length gain was not correlated with initial height in the zinc-supplemented group ( r=−0.13 ) , P=0.5 ) , but was significantly correlated in the control group ( r=-0.6 , P<0.0007 ) . Zinc-supplemented and stunted children ( ≤ 90 % length for age n=18 ) experienced significantly fewer episodes of diarrhoea ( 0.07 vs 0.6 , P 0.05 ) and respiratory illness ( 1.0 vs 2.4 , P<0.01 ) compared to the control group . The underweight children ( ≤ 71 % weight/age n=38 ) receiving zinc-supplementation also had fewer episodes of diarrhoea ( 0.4 vs 1.0 , P<0.04 ) and shorter duration of diarrhoeal episodes ( 1.0 vs 3.0 d , P<0.04 ) compared to their counterparts in the control group . Conclusion : These results suggest that a short course of zinc supplementation to malnourished children during acute diarrhoea reduces growth-faltering and diarrhoeal and respiratory morbidity during subsequent two months . Sponsorship : Wellcome Trust Background / Objective : The efficacy of zinc combined with vitamin A or multiple micronutrients in preventing diarrhoea is unclear in African countries with high prevalence of human immunodeficiency virus (HIV)-exposed children . Potential modifying factors , such as stunting , need to be addressed . The objective of this study was to determine whether adding zinc or zinc plus multiple micronutrients to vitamin A reduces diarrhoea incidence , and whether this differs between the strata of stunted or HIV-infected children . Methods : We analyzed data from a r and omized , controlled , double-blinded trial ( Clinical Trials.gov NCT00156832 ) of prophylactic micronutrient supplementation to children aged 6–24 months . Three cohorts of children : 32 HIV-infected children , 154 HIV-uninfected children born to HIV-infected mothers and 187 uninfected children born to HIV-uninfected mothers , received vitamin A , vitamin A plus zinc or multiple micronutrients , which included vitamin A and zinc . The main outcome was incidence of diarrhoea . Poisson regression was used in intent-to-treat analyses . Stratified analyses followed testing for statistical interaction between intervention and stunting . Results : We observed no significant differences in overall diarrhoea incidence among treatment arms . Stunting modified this effect with stunted HIV-uninfected children having significantly lower diarrhoea incidence when supplemented with zinc or multiple micronutrients compared with vitamin A alone ( 2.04 and 2.23 vs 3.92 episodes/year , respectively , P=0.024 ) . No meaningful subgroup analyses could be done in the cohort of HIV-infected children . Conclusions : Compared with vitamin A alone , supplementation with zinc and with zinc and multiple micronutrients , reduced diarrhoea morbidity in stunted rural South African children . Efficacy of zinc supplementation in HIV-infected children needs confirmation in studies that represent the spectrum of disease severity and age groups The impact of zinc supplementation on the growth and body composition of Guatemalan infants was assessed in a community-based , double-blind intervention trial . Infants aged 6 - 9 mo were assigned r and omly to receive 4 mL of a beverage containing 10 mg of zinc as zinc sulfate ( n = 45 ) or a placebo ( n = 44 ) daily ( 7 d/wk ) for an average of 6.9 mo . The children 's weight , length , mid-upper arm and head circumferences , and triceps skinfolds were measured at baseline and at 1 - 2 mo intervals until the end of supplementation . Midarm muscle area ( MMA ) was derived from the mid-upper arm circumference and triceps skinfolds measurements . Maternal anthropometry and family socioeconomic and demographic characteristics also were obtained . Zinc supplementation was associated with an overall increase of 0.61 cm2 in MMA ( P = 0.02 ) . Children who received zinc supplements had a mean length increment that was 0.75 cm greater than those who did not ( P = 0.12 ) . However , there was a significant interaction between treatment group and initial length-for-age status ( P = 0.04 ) , such that supplemented children who were stunted at baseline ( length-for-age Z score less than -2 ) gained 1.40 cm more than stunted children who received the placebo . We conclude that zinc supplementation of these rural Guatemalan infants during 6 . 9 mo increased accretion of fat-free mass and enhanced the linear growth of those who were stunted at baseline . Further research is required to determine whether zinc supplementation during longer periods of time may achieve larger and more generalized effects on physical growth The effects of a zinc supplement on growth velocity were assessed in a double-blind , pair-matched controlled study in 40 children with low growth percentiles . Participants were low-income Spanish-American children , 2 to 6 yr of age with heights below the 10th percentile and nutritional or biochemical evidence of zinc deficiency . After 1 yr , the mean height velocity of the zinc-supplemented children was slightly , but significantly ( p less than 0.005 ) , greater than that of control children . This effect was primarily due to a greater height achievement of the zinc-supplemented boys . Increases in height-for-age z-scores were also significant for the supplemented males ( p less than 0.001 ) and for the combined sexes ( p less than 0.05 ) . This study indicates the existence of a growth-limiting syndrome of mild zinc deficiency in children Objectives : We assessed the effect of zinc for the treatment of diarrhoea implemented at the community level on physical growth among children 6 to 35 months of age . Methods : The service areas of 30 community health workers in the Matlab field site of International Centre for Diarrhoeal Disease Research , Bangladesh , were r and omly allocated to the intervention or comparison study arm . Between November 1998 and October 2000 , caretakers of 3- to 59-month-old children with diarrhoea in both intervention and comparison areas were offered oral rehydration solution and feeding advice , and severe episodes were referred for facility-based care . The caretakers of the children in the intervention area were additionally offered 20 mg/day elemental zinc for 14 days as adjunct treatment for each diarrhoea episode . Weight and length of children who were 6 to 11 months of age at the beginning of the study were measured every 2 months for 2 years . Rates of length and weight gains were compared between children living in intervention and control arms using a latent growth model . Results : Characteristics of children living in control and intervention areas were similar , except that more children living in intervention areas were underweight at baseline ( 44 vs 35 % ; P = 0.02 ) . Children living in intervention clusters gained slightly more weight and length than children in the control clusters ( 86.4 g/year and 2.8 mm/year , respectively ) . Conclusions : The therapeutic use of zinc along with oral rehydration solution for community-based diarrhoea management may have a small positive benefit on the rates of growth among children younger than 3 years of age Physical growth retardation is an early and prominent feature of zinc deficiency , but the effect of  zinc supplementation in children is still not completely clear . This study investigated the impact of zinc supplementation on linear growth , growth velocity , IGF-I levels , and skeletal maturation of short children during and after mineral supplementation . The study was design ed as a double-blind , r and omized , controlled trial of zinc supplementation during a 6-month period , with a subsequent 6-month follow-up . Anthropometric data were collected at 0 , 6 , and 12 months . Measurements included plasma Zn , IGF-I , height , weight , triceps skinfold thickness , and body mass index .  Eighteen healthy pre-pubertal short children ( z-score -2.0 ) 7 to 10 years old with normal GH and IGF-I levels were r and omized to two groups , one with zinc supplementation ( 5 mg/kg/d of ZnSO4 ) and the other with placebo . In the first 6 months , only height velocity increased significantly , 5.99+/-0.80 cm/yr vs 5.05+/-0.85 cm/yr ( p=0.03 ) . After 12 months , height velocity returned to the initial values , 3.92+/-0.59 cm/yr vs 4.19+/-1.08 cm/yr ( p=0.29 ) . This study indicates that zinc supplementation increased growth velocity , but these effects did not persist after supplementation was discontinued Our objective in this trial was to assess the impact of daily zinc supplementation on growth in young children .  A double-blind , r and omized , placebo-controlled trial was conducted in New Delhi , India . We enrolled 2482 children aged 6 - 30 mo who were supplemented daily with placebo or zinc ( 10 mg elemental zinc to infants and 20 mg to older children ) for 4 mo . At enrollment , all children also received a single dose of vitamin A ( 104.7 micromol for infants and 209.4 micromol for older children ) . Weight and length were measured at enrollment and 4 mo later . Weekly visits were conducted by field workers to ascertain morbidity in the previous 7 d. Change in length , weight , length-for-age Z-scores ( LAZ ) , and weight-for-length Z-scores ( WLZ ) after 4 mo of supplementation were assessed in the zinc and placebo groups . After 4 mo of supplementation , the weight and length gains in the 2 groups did not differ and there was no impact on LAZ , weight-for-age , and WLZ in the 2 groups . There was no substantial effect in any of the subgroups defined for age , income , gender , zinc levels in the crude analysis nor after adjusting for age , gender , income , breast-feeding status , and baseline anthropometric status . Despite successful zinc supplementation reflected in increased plasma zinc concentration and a substantially reduced incidence of diarrhea and pneumonia in zinc-supplemented children , the intervention did not have a beneficial effect on growth Data from 4 r and omized , placebo-controlled , double-blind trials in Indonesia , Thail and , and Vietnam , the South-East Asian Multicountry Trial on Iron and Zinc supplementation in Infants ( SEAMTIZI ) , were pooled to investigate the effects of iron and zinc supplementation infant growth . Infants ( n = 2451 ) aged 4 - 6 mo old were supplemented with iron ( 10 mg/d ) and /or zinc ( 10 mg/d ) for 6 mo . Overall , neither iron nor zinc supplementation prevented the progressive growth faltering during infancy , which is common in many developing countries . However , infants who received zinc were less likely to be stunted at the end of the supplementation period ( odds ratio 0.80 ; 95 % CI 0.64 - 1.0 ) . Boys had a 30 % higher risk of being stunted at the end of the study than girls ( P < 0.01 ) . Baseline factors modified the effect of supplementation , with infants anemic at baseline ( hemoglobin < 105 g/L ) benefiting from zinc supplementation , with an estimated increase in height-for-age Z-score ( HAZ ) score of 0.17 ( P < 0.01 ) , but with no effect of zinc supplementation on growth in infants not anemic at baseline . Iron supplementation negatively affected linear growth in infants with a birth weight of > 3500 g ( estimated effect size , -0 . 14 HAZ score ; P < 0.01 ) , but with no significant effect in infants with a lower birth weight . This study shows that blanket supplementation of infants with iron or zinc will not be beneficial to all recipients and may have adverse effects in some . Hence , interventions such as iron and zinc supplementation for infants should be restricted to subgroups in which there is a clear benefit and baseline factors should be considered and characterized before implementing new policies BACKGROUND Zinc supplementation can reduce subsequent morbidity in children recovering from diarrhoea and respiratory illness in developing countries . However , whether routine supplementation would decrease morbidity and mortality in population s with zinc deficiency is unclear . We assessed the effect of daily zinc supplementation on children in southern Nepal . METHODS We did a community-based , cluster-r and omised , double-masked , placebo-controlled , 2x2 factorial trial in children aged 1 - 35 months . Treatment groups were placebo , iron and folic acid , zinc , and iron and folic acid with zinc , with daily doses of 12.5 mg iron , 50 microg folic acid , and 10 mg zinc . Study staff gave children tablets on 2 days each week and left tablets with caregivers for other days . All children received vitamin A supplementation twice per year . Results of the iron arm of the trial have been reported previously . Between October , 2001 , and January , 2006 , 41,276 children were enrolled into the placebo ( n=20,308 ) or zinc ( n=20,968 ) groups and were followed-up for 60,636.3 person-years . The primary outcome was child mortality , and analyses were by intention to treat . Daily reports of signs and symptoms of common morbidities in stratified r and om sub sample s of children were assessed every week for 12 months . This study is registered at Clinical Trials.gov , number NCT00109551 . FINDINGS 2505 children refused to continue the trial and 3219 children were lost to follow-up . There was no significant difference in mortality between the zinc and placebo groups ( 316 vs 333 deaths ; hazard ratio 0.92 , 95 % CI 0.75 - 1.12 ) . Zinc had no effect on mortality in children younger than 12 months ( 181 vs 168 deaths ; 1.04 , 0.83 - 1.31 ) ; mortality was lower , but not statistically significantly so , in older children receiving zinc ( 135 vs 165 ; 0.80 , 0.60 - 1.06 ) . The frequency and duration of diarrhoea , persistent diarrhoea , dysentery , and acute lower respiratory infections did not differ between the groups . INTERPRETATION Total mortality of children receiving zinc supplementation was not significantly different from that of children receiving placebo . Further data are needed from other population s with endemic zinc deficiency to confirm the potential age-specific effects reported in this study
Conclusions : Many of the children in the included studies were already stunted and may have been suffering from multiple micronutrient deficiencies , and therefore zinc supplementation alone may have only a limited effect on growth
Background / objectives : It is estimated that zinc deficiency affects 17 % of the world 's population , and because of periods of rapid growth children are at an increased risk of deficiency , which may lead to stunting .
This paper presents a systematic review and meta- analysis of the r and omised controlled trials ( RCTs ) that assess zinc intake and growth in children aged 1–8 years .