Supplementation with vitamin A reduces watery diarrhoea and respiratory infections in Mexican children

Previous clinical vitamin A trials have found no consistent effect on diarrhoeal disease and respiratory tract infection. These inconsistent results may be due to the distinct effects vitamin A supplementation has among children stratified by factors related to socio-economic status, nutritional status and season. We evaluated the effect of supplementation on the overall incidence of diarrhoeal disease and respiratory tract infections and on the incidence among children stratified by these factors. A total of 188 children, aged 6-15 months, from periurban, marginalized communities of Mexico City were assigned to receive vitamin A ( < 12 months of age, 20,000 IU retinol; >or= 12 months, 45,000 IU retinol) or a placebo every 2 months, and were followed for up to 15 months. Project personnel visited households twice a week to determine the onset and duration of diarrhoeal disease and respiratory tract infections. Vitamin A supplementation had no significant effect on risk of overall diarrhoeal disease but reduced mild watery diarrhoea (incidence rate ratio (RR) 0.69; 95 % CI 0.50, 0.93) and cough with fever (RR 0.69; 95 % CI 0.48, 0.98). Vitamin A supplementation decreased diarrhoeal disease during the summer (RR 0.74; 95 % CI 0.57, 0.94), among non-stunted children (RR 0.69; 95 % CI 0.52, 0.93) and among children from households with better socio-economic measures. Heterogeneity in the response to vitamin A supplementation may reflect heterogeneity in the aetiology and epidemiology of diarrhoeal disease and respiratory tract infections and the impact that supplementation has on the immune response.     

Respiratory infections reduce the growth response to vitamin A supplementation in a randomized controlled trial

BACKGROUND: Studies on the effect of vitamin A supplementation on growth have yielded various results. It is possible that such growth is dependent on the burden of infectious diseases in the population. METHODS: We analysed data from a randomized, double-masked, placebo-controled trial to examine the role of respiratory infections and diarrhoea in modifying the growth response to vitamin A supplementation. A single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months, and 4430 child treatment cycles were used in this analysis. RESULTS: Vitamin A supplementation modestly improved linear but not ponderal growth of children who experienced little respiratory infection and especially of those who had vitamin A intake below the normative requirement (<400 RE/day). Children who received vitamin A and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height than the placebo group, but those with > or =21.5% of days of respiratory infection did not show a significant growth response to vitamin A supplementation. Children who experienced no respiratory infection and had vitamin A intake <400 RE/day benefited most, gaining 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height compared to the placebo group. Diarrhoea was associated with poorer growth, but did not significantly modify the effect of vitamin A supplementation on growth. CONCLUSIONS: Vitamin A supplementation improves the linear growth of children who have a low intake of vitamin A but this impact is muted with increasing levels of respiratory infections.     

辅助食品补充物对婴幼儿贫血的影响

目的　探讨补充含有蛋白质、微量营养素的辅助食品对婴幼儿血红蛋白和贫血的影响。方法　从甘肃省 5个贫困县选取 4～ 12个月的婴幼儿分成两组 ,其中配方 1组补充了蛋白质和微量营养素 ,两组儿童均观察到 2岁为止。补充期间 ,每隔 6个月对儿童进行一次大剂量维生素A补充 ,并进行血红蛋白测量。结果　基线调查时 ,两组儿童的血红蛋白及贫血率没有显著性差别。补充了 12个月后 ,配方 1组儿童血红蛋白的增加值高于配方 2组 (P <0 0 0 0 5 ) ,儿童贫血率明显下降 ,两配方组之间贫血率有显著差别 ;所有儿童至满 2岁时 ,配方 1组的血红蛋白增加值大于配方 2组 ,有统计学显著意义 (P =0 0 0 6 )。结论　补充微量营养素和大剂量的维生素A可以增加婴幼儿的血红蛋白值 ,降低其贫血率。     

The effect of vitamin A supplementation on the intestinal immune response in Mexican children is modified by pathogen infections and diarrhea

Vitamin A supplementation has consistently reduced infant mortality and the severity of pathogen-induced diarrhea. The mechanism by which vitamin A modulates the mucosal immune response to produce these effects remains poorly defined. To address this issue, stools collected during the summer months from 127 Mexican children 5-15 mo old enrolled in a larger, randomized, double-blind, placebo-controlled, vitamin A supplementation trial were screened for interleukin (IL)-4, IL-6, interferon-gamma (IFN-gamma), and gastrointestinal pathogens. Fecal cytokine values were categorized into 3 levels (undetectable, or =median). Multinomial regression models were used to determine the probability that vitamin A-supplemented children had higher categorical values of a cytokine than children in the placebo group. Differences in categorical values were also analyzed after stratification by gastrointestinal pathogen infections and diarrheal symptoms. Overall, fecal cytokine categorical levels did not differ between children randomized to the 2 arms. Vitamin A-supplemented children infected with enteropathogenic E. coli (EPEC) had reduced IL-4 and IFN-gamma levels [odds ratio (OR) = 0.3, 95% CI 0.13-0.67 and OR = 0.34, 95% CI 0.14-0.83, respectively] compared with children in the placebo group. Vitamin A-supplemented children had increased IL-4 levels when infected with A. lumbricoides (OR = 12.06, 95% CI 0.95-153.85). In contrast, IL-4 levels increased (OR = 2.14, 95% CI 0.94-4.87) and IFN-gamma levels decreased (OR = 0.51, 95% CI 0.26-0.99) among vitamin A-supplemented children with diarrhea compared with children in the placebo group. These findings suggest that the regulation of the mucosal immune response by vitamin A may depend on the type of enteric pathogen infecting the child and the presence of clinical symptoms.     

Vitamin A supplementation reduces the monocyte chemoattractant protein-1 intestinal immune response of Mexican children

The impact of vitamin A supplementation on childhood diarrhea may be determined by the regulatory effect supplementation has on the mucosal immune response in the gut. Previous studies have not addressed the impact of vitamin A supplementation on the production of monocyte chemoattractant protein 1 (MCP-1), an essential chemokine involved in pathogen-specific mucosal immune response. Fecal MCP-1 concentrations, determined by an enzyme-linked immuno absorption assay, were compared among 127 Mexican children 5-15 mo of age randomized to receive a vitamin A supplement (<12 mo of age, 20,000 IU of retinol; > or =12 mo, 45,000 iu) every 2 mo or a placebo as part of a larger vitamin A supplementation trial. Stools collected during the summer months were screened for MCP-1 and gastrointestinal pathogens. Values of MCP-1 were categorized into 3 levels (nondetectable, or =median). Multinomial logistic regression models were used to determine whether vitamin A-supplemented children had different categorical values of MCP-1 compared with children in the placebo group. Differences in categorical values were also analyzed stratified by gastrointestinal pathogen infections and by diarrheal symptoms. Overall, children who received the vitamin A supplement had reduced fecal concentrations of MCP-1 compared with children in the placebo group (median pg/mg protein +/- interquartile range: 284.88 +/- 885.35 vs. 403.39 +/- 913.16; odds ratio 0.64, 95% CI 0.42-97, P = 0.03). Vitamin A supplemented children infected with enteropathogenic Escherichia coli (EPEC) had reduced MCP-1 levels (odds ratio = 0.38, 95% CI 0.18-0.80) compared with children in the placebo group. Among children not infected with Ascaris lumbricoides vitamin A supplemented children had reduced MCP-1 levels (OR = 0.62, 95% CI 0.41-0.94). These findings suggest that vitamin A has an anti-inflammatory effect in the gastrointestinal tract by reducing MCP-1 concentrations.     

Effect of vitamin A supplementation on diarrhoea and acute respiratory tract infection in children

To determine the effect of a massive single oral dose of Vitamin A (200,000 IU) supplementation on diarrhoea and acute respiratory infection (ARI), a double blind placebo controlled trial involving 174 children under six years of age (excluding infants) was carried out in a Calcutta slum community. Ninety-one children received vitamin A supplementation (experimental group) and 83 children received a placebo (control group). All the children were followed up for six months by active fortnightly surveillance for occurrence of diarrhoea or ARI and their duration. There was no statistically significant difference in the incidence of diarrhoeal episodes or ARI. However, there was a significant difference (p<0.05) in the average duration of diarrhoea per episode (2.1 vs. 3 days) between the experimental and control groups. Possible beneficial effects of a single oral dose of vitamin A supplementation on the incidence of diarrhoea and ARI could not be demonstrated in the present study.     

Suppressive effect of zinc on antibody response to cholera toxin in children given the killed, B subunit-whole cell, oral cholera vaccine

In a previous study, children aged 2-5 years old in Bangladesh were supplemented orally with a single dose of Vitamin A (200,000 IU) and a placebo for zinc (zinc equivalent to 20 mg of elemental zinc) everyday for 42 days (group A), zinc and a placebo for Vitamin A (group Z), zinc and Vitamin A (group AZ) or both placebos (group P). All children were orally immunised with two doses of the killed cholera vaccine containing whole cells and a recombinant B subunit of cholera toxin (CT). The number of children who responded with > or = 4-fold vibriocidal antibody (a proxy indicator of protection against cholera) was significantly greater among the zinc-supplemented groups than among the non-zinc-supplemented groups, while Vitamin A supplementation did not appear to have any effect. The sera from these children were assayed for antibody to CT. Antibody to CT is known to exert a synergistic protective effect against cholera in animal studies, and offer significantly higher short-term protection against cholera and significant short-term protection against enterotoxigenic Escherichia coli diarrhoea in humans on oral immunisation with the cholera vaccine. Children who received zinc had significantly reduced levels of serum antibodies to CT than children who received placebos only. Factorial analysis showed a trend for zinc showing a reduction in the number of children responding with CT-antibody, while Vitamin A did not appear to have any effect. Thus, zinc enhanced vibriocidal antibody response, but suppressed CT-antibody response, suggesting that zinc supplementation has different modulating effects on vibriocidal antibody response and CT-antibody response.     

Impact of vitamin A supplementation on health status and absenteeism of school children in Sri Lanka

The objective of this study was to determine the impact of Vitamin A supplementation on health status and absenteeism of school children. A randomized double blind placebo controlled trial over a period of 13 months was conducted in a rural area of Sri Lanka involving 613 school children attending Grades 1-5 (aged 5 to 13 years). Children were assigned to either 200,000 IU of Vitamin A (n=297) or placebo (n=316) once every 4 months. Socio-demographic data were obtained at baseline, and anthropometry and haemoglobin concentrations were assessed at baseline and post intervention. Serum vitamin A concentrations were assayed by HPLC in a subgroup of children (n=193) before administration of each dose. School absenteeism was recorded. The two groups of children were similar at baseline in all variables. The subgroup of children was comparable to the main study population. The prevalence of vitamin A deficiency (< 20 microg/dL) in the subgroup of children was 8.2%. Changes in anthropometric indices and haemoglobin concentrations were similar in the two groups. The major causes for absenteeism were non-health causes and supplemented children lost a fewer number of school days due to illness than placebo children (p=0.053). Vitamin A concentrations improved with each dose and the improvement was greater with better compliance. Vitamin A supplementation with 200,000 IU every 4 months over 13 months improved vitamin A status and school attendance but not anthropometric status of these children.     

Consumption of Vitamin-A-Rich Foods and Vitamin A Supplementation for Children under Two Years Old in 51 Low- and Middle-Income Countries

Vitamin A supplementation for children 6–59 months old is an important intervention that boosts immune function, especially where children do not consume enough vitamin-A-rich foods. However, the low coverage of vitamin A supplementation is a persistent problem in low- and middle-income countries. We first estimated the percentage of children 6–23 months old receiving the minimum dietary diversity, vitamin-A-rich foods, and vitamin A supplementation, and second, the difference in the percentage receiving vitamin A supplementation between children 6–23 months old and children 24–59 months old using nationally representative cross-sectional household surveys, namely, the Demographic and Health Surveys, conducted from 2010 to 2019 in 51 low- and middle-income countries. Overall, 22% (95% CI: 22, 23) of children received the minimum dietary diversity, 55% (95% CI: 54, 55) received vitamin-A-rich foods, 59% (95% CI: 58, 59) received vitamin A supplementation, and 78% (95% CI: 78, 79) received either vitamin-A-rich foods or supplementation. A wide variation across countries was observed; for example, the percentage of children that received either vitamin-A-rich foods or supplementation ranged from 53% (95% CI: 49, 57) in Guinea to 96% (95% CI: 95, 97) in Burundi. The coverage of vitamin A supplementation should be improved, especially for children 6–23 months old, in most countries, particularly where the consumption of vitamin-A-rich foods is inadequate.     

A double-blind, randomized, clinical trial of the effect of vitamin A and zinc supplementation on diarrheal disease and respiratory tract infections in children in Mexico City, Mexico

BACKGROUND: The efficacy of micronutrient supplementation in improving childhood health and survival in developing countries may be specific to the micronutrient used and health outcome measured. OBJECTIVE: We evaluated the effect of vitamin A and zinc supplementation on overall rates of childhood diarrheal disease and respiratory tract infections and rates stratified by household and personal characteristics. DESIGN: A double-blind, randomized, placebo-controlled trial was carried out in which 736 children aged 6-15 mo living in a periurban area of Mexico City were assigned to receive vitamin A every 2 mo, zinc daily, vitamin A and zinc together, or placebo. Children were followed for 12 mo to determine overall counts of diarrheal episodes and respiratory tract infections. RESULTS: Vitamin A supplementation was associated with a 27% increase in diarrheal disease [risk ratio (RR): 1.27; 95% CI: 1.10, 1.45; P < 0.001] and a 23% increase in cough with fever (RR: 1.23; 95% CI: 1.02, 1.47; P = 0.02), whereas zinc had no effect on these outcomes. Vitamin A supplementation decreased diarrhea in children from households with dirt floors but increased diarrhea in children from households with nondirt floors, piped water, and indoor bathrooms. Zinc supplementation decreased diarrhea in children from households with dirt floors and whose mothers were more educated. Vitamin A supplementation increased cough with fever in children from less-crowded households that lacked indoor bathrooms and in children of less-educated mothers. CONCLUSIONS: Vitamin A increases diarrheal disease and respiratory tract infections in young children in periurban areas of Mexico City. Vitamin A and zinc have more heterogeneous effects in different subgroups of children.     

Vitamin A supplementation selectively improves the linear growth of indonesian preschool children: results from a randomized controlled trial

BACKGROUND: Vitamin A deficiency is associated with stunting and wasting in preschool children, but vitamin A supplementation trials have not shown a consistent effect on growth. OBJECTIVE: We examined the effect of vitamin A supplementation on height and weight increments among Indonesian preschool children. DESIGN: Data were obtained from a randomized, double-masked, placebo-controlled trial of rural Javanese children aged 6-48 mo. Children received 206000 IU vitamin A (103000 IU if aged <12 mo) or placebo every 4 mo. RESULTS: High-dose vitamin A supplementation modestly improved the linear growth of the children by 0.16 cm/4 mo. The effect was modified by age, initial vitamin A status, and breast-feeding status. Vitamin A supplementation improved height by 0.10 cm/4 mo in children aged <24 mo and by 0.22 cm/4 mo in children aged >/=24 mo. The vitamin A-supplemented children with an initial serum retinol concentration <0.35 micromol/L gained 0.39 cm/4 mo more in height and 152 g/4 mo more in weight than did the placebo group. No growth response to vitamin A was found among children with an initial serum retinol concentration >/=0.35 micromol/L. In non-breast-fed children, vitamin A supplementation improved height by 0.21 cm/4 mo regardless of age. In breast-fed children, vitamin A supplementation improved linear growth by approximately 0.21 cm/4 mo among children aged >/=24 mo, but had no significant effect on the growth of children aged <24 mo. CONCLUSION: High-dose vitamin A supplementation improves the linear growth of children with very low serum retinol and the effect is modified by age and breast-feeding.     

Vitamin A modifies the intestinal chemokine and cytokine responses to norovirus infection in Mexican children

Vitamin A supplementation is associated with divergent clinical norovirus (NoV) outcomes in Mexican children. Fecal cytokine concentrations following NoV genogroup infections among 127 Mexican children 5-15 mo old enrolled in a randomized, double-blind, placebo-controlled, vitamin A supplementation trial were determined to clarify the role the gut immune response plays in these associations. Stools collected from supplemented children [20,000 IU retinol (3.3 IU = 1 μg retinol) for children < 12 mo of age; 45,000 iu for children ≥ 12 mo] or children in the placebo group were screened for NoV genogroups I (GI) and II (GII). Monocyte chemoattractant protein-1 (MCP-1), TNFα, IL-5, IL-6, IL-8, IL-4, IFNγ, and IL-10 fecal concentrations were also determined. Differences in cytokine levels between the 2 groups following GI and GII infections were determined using ordered logistic regression models. MCP-1 and IL-8 levels were greater among GI- and GII-infected children, respectively, compared with uninfected children, whereas IL-5 levels were greater following both genogroup infections. MCP-1, IL-8, and IL-6 fecal levels were reduced among supplemented children with GII-associated diarrhea compared with the placebo group. Vitamin A-supplemented, GII-infected children had reduced MCP-1 and TNFα levels compared with GII-infected children in the placebo group (P-interaction = 0.02 and 0.03, respectively). Supplemented children with GI-associated diarrhea had higher TNFα and IL-4 levels compared with children in the placebo group with diarrhea (P-interaction = 0.02 and 0.02, respectively). The divergent effects of supplementation on NoV outcomes may result from the different effects vitamin A has on the genogroup-specific immune responses.     

补充维生素D对小囟门婴幼儿头围发育及智力测评的影响

目的 探讨婴幼儿补充维生素D对小囟门儿童头围发育及Bayley智力测评结果的关系。方法 选择2010年1月-2011年11月在湖州市妇幼保健院体检的正常儿童118例作为观察对象, 分为小囟门组和正常对照组, 均给与维生素D, 分别在月龄3、12、18个月三个时间节点测量头围值, 同时在6、18个月两个时间节点做Bayley智力测试。结果 小囟门组与对照组儿童在3、12、18个月头围值差异均无统计学意义(P>0.05);两组与相应年龄小儿头围正常值比较差异无统计学意义(P>0.05);两组儿童6、18个月Bayley智力测试结果均为正常。结论 服用预防剂量的维生素D不会影响小囟门儿童头围的发育及智能发育, 无论前囟大小均应服用预防剂量的维生素D。     

Effect of micronutrient supplementation on linear growth of children

This review summarizes the results of published, randomized clinical trials that have examined the impact of administration of micronutrients, singly or in combination to infants, preschool and school children on linear growth. Supplementation of single micronutrients resulted in small or no benefits on linear growth. A meta-analysis of zinc supplementation trials confirmed that zinc has a significant but small impact (0.22 sd units) on length gain in children 0-13 years of age. However, a recent study reported a substantially greater benefit (>1 sd) in stunted and non-stunted breast-fed infants 6-12 months of age. With iron supplementation, a beneficial effect was found only in anemic children. Vitamin A supplementation trials have reported little or no benefit on linear growth. Data currently available suggest some impact in children with clinical or biochemical vitamin A deficiency, but this issue needs confirmation. Few studies could be identified where a combination of micronutrients was given as a supplement or as fortified food; in the latter set of studies energy availability was assured. The impact on length without multiple micronutrient supplementation was no greater than that observed with single micronutrients. In conclusion, zinc and iron seem to have a modest effect on linear growth in deficient populations. Vitamin A is unlikely to have an important effect on linear growth. Limited available evidence does not allow us to conclude whether a combination of micronutrients, with or without additional food, would have a greater impact than that seen with zinc alone.     

补充维生素D对小囟门儿童头围发育及Bayley智力测评结果的影响

目的：探讨婴幼儿补充维生素D对小囟门儿童头围发育及Bayley智力测评结果的关系。方法：选择2010年1月至2011年11月在湖州市妇幼保健院体检的正常儿童118例作为观察对象,分为小囟门组和正常对照组,均给与维生素D预防佝偻病,分别在3个月、12个月、18个月三个时间节点测量头围值,同时在6个月、18个月两个时间节点分别做Bayley智力测试,分析其关系。结果：小囟门组与对照组在3个月、12个月、18个月时头围值均无统计学意义（P〉0.05）;且两组与相应年龄小儿头围正常值比较无统计学意义（P〉0.05）;两组小儿6个月、18个月Bayley智力测试结果均为正常。结论：服用预防剂量的维生素D不会阻碍婴幼儿头围的发育,对智力没有影响。无论前囟大小应服用维生素D预防佝偻病。     

Immunogenicity and safety of the RTS,S/AS01 malaria vaccine co-administered with measles,rubella and yellow fever vaccines in Ghanaian children: A phase IIIb,multi-center,non-inferiority,randomized, open,controlled trial

BackgroundTo optimize vaccine implementation visits for young children, it could be efficient to administer the first RTS,S/AS01 malaria vaccine dose during the Expanded Programme on Immunization (EPI) visit at 6 months of age together with Vitamin A supplementation and the third RTS,S/AS01 dose on the same day as yellow fever (YF), measles and rubella vaccines at 9 months of age. We evaluated the safety and immunogenicity of RTS,S/AS01 when co-administered with YF and combined measles-rubella (MR) vaccines.MethodsIn this phase 3b, open-label, controlled study (NCT02699099), 709 Ghanaian children were randomized (1:1:1) to receive RTS,S/AS01 at 6, 7.5 and 9 months of age, and YF and MR vaccines at 9 or 10.5 months of age (RTS,S coad and RTS,S alone groups, respectively). The third group received YF and MR vaccines at 9 months of age and will receive RTS,S/AS01 at 10.5, 11.5 and 12.5 months of age (Control group). All children received Vitamin A at 6 months of age. Non-inferiority of immune responses to the vaccine antigens was evaluated 1 month following co-administration versus RTS,S/AS01 or EPI vaccines (YF and MR vaccines) alone using pre-defined non-inferiority criteria. Safety was assessed until Study month 4.5.ResultsNon-inferiority of antibody responses to the anti-circumsporozoite and anti-hepatitis B virus surface antigens when RTS,S/AS01 was co-administered with YF and MR vaccines versus RTS,S/AS01 alone was demonstrated. Non-inferiority of antibody responses to the measles, rubella, and YF antigens when RTS,S/AS01 was co-administered with YF and MR vaccines versus YF and MR vaccines alone was demonstrated. The safety profile of all vaccines was clinically acceptable in all groups.ConclusionsRTS,S/AS01 can be co-administered with Vitamin A at 6 months and with YF and MR vaccines at 9 months of age during EPI visits, without immune response impairment to any vaccine antigen or negative safety effect.     

Hematological effect of supplementing anemic children with vitamin A alone and in combination with iron

Ninety-nine anemic children aged 1-8 y were divided into four groups. Each group was supplemented for 2 mo with vitamin A, iron, vitamin A plus Fe, or a placebo. Clinical, hematological, and Fe biochemical evaluations were performed at the beginning and end of the study. Vitamin A supplementation produced significant elevations in the serum levels of retinol, blood hemoglobin, hematocrit, erythrocytes, serum Fe, and percent transferrin saturation (%TS) and had no effect on total Fe binding capacity (TIBC) or serum ferritin. Fe supplementation did not affect serum retinol. However, it improved hematological and Fe nutrition indicators, including TIBC and serum ferritin. The simultaneous administration of vitamin A and Fe resulted in a better response of serum Fe and %TS than when the supplement consisted only of vitamin A or Fe alone. Vitamin A benefits hematological condition and Fe metabolism.     

Evaluation of the effectiveness of the national vitamin A supplementation programme among school children in Sri Lanka

The Ministry of Health in Sri Lanka commenced a vitamin A supplementation programme of school children with a megadose of 105 micromol (100,000 IU) vitamin A in school years 1, 4 and 7 (approximately 5-, 9- and 12-year-olds, respectively) in 2001. We evaluated the vitamin A supplementation programme of school children in a rural area of Sri Lanka. A cross-sectional study was conducted among children supplemented with an oral megadose of vitamin A (105 micromol; n 452) and children not supplemented (controls; n 294) in Grades 1-5. Children were clinically examined and a sample of blood was taken for serum vitamin A concentration estimation by HPLC. Socio-demographic information was obtained from children or mothers. Supplemented children had a higher proportion of males and stunted children, were younger and lived under poorer conditions as compared to controls. There was no difference in the prevalences of eye signs and symptoms of vitamin A deficiency in the two groups. Supplemented children had higher serum vitamin A concentrations than controls (1.4 (SD 0.49) micromol/l v. 1.2 (SD 0.52) micromol/l). The serum vitamin A concentrations were 1.6 (SD 0.45), 1.4 (SD 0.50), 1.3 (SD 0.44) and 1.1 (SD 0.43) micromol/l in children supplemented within 1, 1-6, 7-12 and 13-18 months of supplementation, respectively. Vitamin A concentrations were significantly greater than controls if supplementation was carried out within 6 months after adjustment. The oral megadose of 105 micromol vitamin A maintained serum vitamin A concentrations for 6 months in school children.     

Effect of daily iron supplementation on iron status, cell-mediated immunity, and incidence of infections in 6-36 month old Togolese children

OBJECTIVE: To assess the impact of a daily oral iron supplementation on hematological status, cell-mediated immunity and susceptibility to infections in children living in an environment where iron deficiency, malaria and other infections are frequent. DESIGN: Randomized, double-blind iron supplementation including a placebo group. SETTING: A village in Togo, West Africa. SUBJECTS: Of the 229 6-36-month-old children of both sexes recruited, 197 with hemoglobin concentration >/=80 g/l were included and 163 completed the study. INTERVENTION: Children received daily a placebo (n=79) or a dose of 2-3 mg of elemental iron per kg of body weight (n=84) for 3 months. Hematological, nutritional and immune status were assessed at the beginning and at the end of the supplementation period, and 6 months later. Morbidity was recorded throughout the study. RESULTS: Iron supplementation had a significant and positive effect on iron status of children and no impact on the incidence of infections, especially malaria. Its probable effect on immune status was masked by interference of infections and their treatment, which contributed to improve hematological and immune status in both groups. CONCLUSION: According to the negative consequences of anemia and iron deficiency on global child development, control of iron deficiency by oral iron supplementation in young children has to be conducted, associated with prophylaxis and treatment of malaria and repeated deworming. SPONSORSHIP: Program supported by IRD. European Journal of Clinical Nutrition (2000) 54, 29-35     

Vitamin A supplementation enhances infants' immune responses to hepatitis B vaccine but does not affect responses to Haemophilus influenzae type b vaccine

Vitamin A supplementation reduces child mortality and severe morbidity in less developed countries, and the Expanded Program on Immunization (EPI) offers an ideal opportunity to deliver supplements in developing countries. High-dose vitamin A supplementation has been shown to have no effect on the immunogenicity of oral polio vaccine, tetanus toxoid, pertussis, or on measles vaccine given at 9 mo, but a negative effect on measles vaccine administered at 6 mo and a potentiating effect on diphtheria vaccine. Its effect on the antibody response to hepatitis B and Haemophilus influenzae type b antigens has not yet been established. To assess these effects, the present trial was carried out in the Offinso district of Ghana; 1077 infants were enrolled shortly after birth and randomized either to receive or not to receive 15 mg retinol equivalent with vitamin A together with the pentavalent "diphtheria-polio-tetanus-Haemophilus influenzae b-hepatitis B" vaccine at 6, 10, and 14 wk of age. All mothers received a postpartum supplement of 120 mg retinol equivalent vitamin A as per national policy. Blood samples were taken from infants at 6 and 18 wk of age. The results are based on 888 infants (82.4%) who completed the trial. The vitamin A supplementation did not affect the immune response to Haemophilus influenzae type b, but there was a significant improvement in the immune response to hepatitis B vaccine (93.9 vs. 90.2%, P = 0.04). However, given the high percentage of infants with seroprotection in the control group, it is doubtful that inclusion of vitamin A in the EPI would be justified on these grounds alone.