Effect of simultaneous supplementation of vitamin A and iron on diarrheal and respiratory tract infection in preschool children in Chengdu City,China

ObjectiveThe goal of this study was to investigate whether vitamin A combined with iron supplementation for preschool children resulted in improved changes in children's infectious morbidity.MethodIn this randomized placebo-controlled and blinded field intervention trial, totally 445 preschoolers, ages 3 to 6 y old, were randomly selected. All children were randomly divided into four groups: vitamin A supplement-only group (group I), iron supplement-only group (group II), vitamin A and iron supplement group (group III), and no vitamin A and ferrous sulfate as placebo-control (group IV) for 6 mo. The morbidity of diarrhea and respiratory infections, were collected during supplementation.ResultsThere was evidence of the lowest incidence rate of respiratory-related illnesses and fewest symptoms of runny nose, cough, and fever for children in group III compared with children in groups I, II and IV (P < 0.05). Moreover, despite the undistinguished incidence rate of vomiting, nausea, and stomach pain, the rate of diarrhea-related illness was significantly lower for children in group III than for those in the other three groups.ConclusionThe beneficial affects on infectious morbidity over 6 mo, highlight the potential of vitamin A plus an iron supplement for preschool-aged children.     

Effect of zinc added to multi-vitamin supplementation containing low-dose vitamin A on plasma retinol level in children--a double-blind randomized, controlled trial

In a community-based double-blind randomized trial in children aged 6-35 months, both intervention and control groups received a multi-vitamin syrup containing vitamin A, while the intervention group had zinc gluconate (equivalent to 10 mg of elemental zinc) additional in the syrup. There was a significant decrease in diarrhoea and pneumonia in the intervention group. This study was undertaken to investigate if addition of zinc to vitamin A had improved plasma retinol levels, which, in turn, was responsible for the effects observed in the intervention group. In a randomly-selected subsample of 200 children--100 each from the intervention and the control group, plasma retinol levels after 120 days of supplementation were measured. There was no difference in the mean plasma retinol levels [the difference in the mean 0.46 microg/dL (95% confidence interval -1.42-2.36)] between the two groups following supplementation. No difference in plasma retinol levels was observed in the subgroups based on base-line nutritional status and plasma zinc levels. Addition of zinc to low-dose vitamin A in this study did not improve the vitamin A status of children and cannot explain morbidity effects of the intervention.     

A double-blind trial of zinc supplementation in pregnancy

A double-blind randomised trial of oral zinc supplementation was carried out during the last two trimesters of pregnancy. Fifty-six women at risk of delivering a small-for-gestational-age baby received either zinc supplement (22.5 mg daily) or placebo. Twenty-nine of the women were compliant. Zinc significantly reduced the incidence of intrauterine growth retardation, and most measured indices of labour and fetal health were better in the supplemented group. Larger studies are now needed to confirm a role for selective zinc supplementation in at-risk pregnancies.     

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.     

Randomized, double-blind, placebo-controlled clinical trial of the efficacy of treatment with zinc or vitamin A in infants and young children with severe acute lower respiratory infection

BACKGROUND: Acute lower respiratory infection (ALRI) is a leading cause of childhood death. Zinc supplementation prevents ALRI. Vitamin A supplementation reduces childhood mortality, but its benefit concerning ALRI-specific mortality is unproven. OBJECTIVE: The objective was to evaluate the effect of zinc and vitamin A on the clinical recovery of children with severe ALRI. DESIGN: In a controlled trial with a factorial design, 153 children aged 2-24 mo who were hospitalized with severe ALRI were randomly assigned to receive 10 mg zinc as acetate (twice daily for 5 d) plus vitamin A placebo, 10 000 micro g retinol equivalents vitamin A (twice daily for 4 d) plus zinc placebo, zinc plus vitamin A, or zinc and vitamin A placebos. The main outcome variable was the time for resolution of very ill status; other outcomes were resolution of fever, tachypnea, and feeding difficulty. RESULTS: Recovery rates from very ill status and from fever in zinc-treated boys were 2.6 times (P = 0.004) and 3 times (P = 0.003) those in non-zinc-treated children; feeding difficulty and tachypnea were not significantly different between groups after an adjusted analysis. Recovery rates were not significantly different between groups on the basis of vitamin A treatment. At discharge, serum zinc was 6.06 micro mol/L higher (P = 0.001) in the zinc-treated children, and serum retinol was 0.387 micro mol/L higher (P = 0.001) in the vitamin A-treated children. CONCLUSION: Zinc treatment significantly reduces duration of fever and very ill status in boys, but not in girls, with severe ALRI. Vitamin A treatment of children with severe ALRI had no significant beneficial effect.     

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.     

Effect of zinc supplementation on growth in West African children: a randomized double-blind placebo-controlled trial in rural Burkina Faso

OBJECTIVE: To analyse the effects of zinc supplementation on growth parameters in a representative sample of young children in rural Burkina Faso. Design Randomized, 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 subsample of study children, 72% were zinc-deficient at baseline. After supplementation, serum zinc increased in zinc-supplemented but not in control children of the subsample. 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 populations of young children with a high prevalence of malnutrition. Multinutrient interventions are likely to be more effective.     

Oral magnesium supplementation in asthmatic children: a double-blind randomized placebo-controlled trial

OBJECTIVE: To investigate the long-term effect of oral magnesium supplementation on clinical symptoms, bronchial reactivity, lung function and allergen-induced skin responses in children and adolescents with moderate persistent asthma. DESIGN: A double-blind randomized parallel placebo-controlled study. SETTING AND SUBJECTS: The patients were recruited from the Pediatric Outpatient Clinic, Division of Pulmonology, Allergy and Immunology, and followed at the Center for Investigation in Pediatrics at State University of Campinas Hospital, Brazil. Thirty-seven out of 72 patients met the study criteria. There were no dropouts. INTERVENTION: The 37 patients (aged 7-19 years, 19 males) were randomized in two groups: magnesium (n=18, 300 mg/day) and placebo (n=19), during 2 months. Both patient groups received inhaled fluticasone (250 microg twice a day) and salbutamol as needed. The primary outcome was bronchial reactivity evaluated with methacholine challenge test (PC20). RESULTS: After a follow-up of 2 months, the methacholine PC20 for testing bronchial reactivity has augmented significantly in the magnesium group only. The skin responses to recognized antigens have also decreased in patients treated with magnesium. The forced vital capacity (FVC), the forced expiratory volume at first second (FEV1), the forced expiratory flow at 25-75 and the FEV1/FVC ratio were similar in both groups. The magnesium group presented fewer asthma exacerbations and used less salbutamol compared to the placebo group. CONCLUSIONS: Oral magnesium supplementation helped to reduce bronchial reactivity to methacholine, to diminish their allergen-induced skin responses and to provide better symptom control in pediatric patients with moderate persistent asthma treated with inhaled fluticasone.     

Vitamin A supplementation reduces measles morbidity in young African children: a randomized, placebo-controlled, double-blind trial

The effects of vitamin A supplementation on measles morbidity are unclear. Sixty hospitalized children aged 4-24 mo with complicated measles received a World Health Organization--(WHO) recommended dose of vitamin A or placebo. The two groups were comparable in known covariants of measles severity: weight-for-age percentiles, overcrowding, rash, total lymphocytes, and serum concentrations of zinc, albumin, prealbumin, retinol-binding protein, and vitamins A and E. Ninety percent of the patients had hyporetinemia. Integrated morbidity scores, determined by severity of condition (eg, diarrhoea, herpes, and respiratory-tract infection) were assigned on day 8 and 6 wk and 6 mo; these were reduced by 82%, 61%, and 85%, respectively, in the supplemented group, which was mainly due to reduced respiratory-tract infection. There was one death in the placebo group. At 6 wk weight gain was significant in the supplemented group. Despite the selected sample, attention to multiple covariates enhances the validity of the data obtained and supports the current WHO recommendations for vitamin A supplementation during measles.     

Impact of vitamin A megadose supplementation on the anthropometry of children and adolescents with non-hormonal statural deficit: a double-blind and randomized clinical study

OBJECTIVE: To evaluate the intake of retinol and carotenoids, and their serum levels, as well as the impact of vitamin A supplementation on the anthropometry and body composition of children and adolescents with non-hormonal-related statural deficit. METHOD: Double-blind, randomized trial of 46 pre-pubertal patients, between 4 and 14 years of age, with normal growth rates. The subjects were divided into two groups, each with 23 individuals (Group I: Placebo; Group II: Vitamin A in a single megadose), and were evaluated at moments A and B with a six month interval. RESULTS: There were no statistically significant differences in serum retinol levels, anthropometry, growth velocity, or body composition, between moments A and B, in Group II. Carotenoids were significantly lower in Group I at moment B. The semi-quantitative food intake questionnaire showed that approximately 60.9% of the children and adolescents ingested less than half of the amounts of retinol and carotenoids recommended by the Food Guide Pyramid. Inadequate intake was more prevalent regarding vegetable and fruit carotenoid sources, with 75 and 70% of inadequacy, respectively. CONCLUSION: If one considers the inadequate food intake observed in the dietary evaluation in this study, it is possible that multiple micronutrient deficiencies could be involved in statural deficits. This could explain why vitamin A supplementation does not seem to influence growth in children and adolescents with statural deficit, as indicated by the present study. Thus in populations such as the one studied here, the supplementation with vitamin A should be integrated into comprehensive nutritional interventions, so as to possibly promote greater positive impact on linear growth.     

A randomized, 4-month mango and fat supplementation trial improved vitamin A status among young Gambian children

Supplementation with carotene-rich fruits may be an effective and sustainable approach to prevent vitamin A deficiency. To test the effectiveness of mango supplementation, 176 Gambian children, aged 2 to 7 y, were randomly assigned to one of four treatments: 75 g of dried mango containing approximately 150 micro g retinol activity equivalents with (MF) or without (M) 5 g of fat, 5 d/wk for 4 mo or 60,000 micro g of vitamin A (A) or placebo (P) capsule at baseline. After 4 mo, plasma beta-carotene was greater in both the M (P < 0.05) and MF (P = 0.07) groups compared with the P group. After controlling for baseline plasma retinol, elevated acute phase proteins and age, plasma retinol concentrations in the A and MF, but not M, groups were higher than in the P group at the end of the study (P < 0.01). Increases in retinol concentrations, however, were small in both groups. These results support the use of dietary supplementation with dried mangoes and a source of fat as one of several concurrent strategies that can be used to help maintain vitamin A status of children in developing countries where there is a severe seasonal shortage of carotenoid-rich foods.     

A randomized, placebo-controlled trial of the effect of zinc supplementation during pregnancy on pregnancy outcome in Bangladeshi urban poor

BACKGROUND: Maternal zinc supplementation has been suggested as a potential intervention to reduce the incidence of low birth weight in developing countries. To date, placebo-controlled trials have all been performed in industrialized countries and the results are inconsistent. OBJECTIVE: The objective of this study was to evaluate whether zinc supplementation in Bangladeshi urban poor during the last 2 trimesters of pregnancy was associated with pregnancy outcome. DESIGN: We conducted a double-blind, placebo-controlled trial in which 559 women from Dhaka slums, stratified by parity between 12 and 16 wk of gestation, were randomly assigned to receive 30 mg elemental Zn/d (n = 269) or placebo (n = 290). Supplementation continued until delivery. Serum zinc was estimated at baseline and at 7 mo of gestation. Dietary intake was assessed at baseline and anthropometric measurements were made monthly. Weight, length, and gestational ages of 410 singleton newborns were measured within 72 h of birth. RESULTS: At 7 mo of gestation, serum zinc concentrations tended to be higher in the zinc-supplemented group than in the placebo group (15.9 +/- 4.4 compared with 15.2 +/- 4.3 micromol/L). No significant effect of treatment was observed on infant birth weight (2513 +/- 390 compared with 2554 +/- 393 g; NS) or on gestational age, infant length, or head, chest, or midupper arm circumference. The incidence and distribution of low birth weight, prematurity, and smallness for gestational age also did not differ significantly after zinc supplementation. CONCLUSIONS: Supplementation with 30 mg elemental Zn during the last 2 trimesters of pregnancy did not improve birth outcome in Bangladeshi urban poor. These results indicate that interventions with zinc supplementation alone are unlikely to reduce the incidence of low birth weight in Bangladesh.     

A double-blind, randomized, controlled crossover trial of glutamine supplementation in home parenteral nutrition

OBJECTIVE: Studies suggest clinical benefit of glutamine-supplemented parenteral nutrition. The aim was to determine if the inclusion of 10 g of glutamine as part of the nitrogen source of home parenteral nutrition (HPN) reduces infectious complications. SUBJECTS/METHODS: Thirty-five patients on HPN were recruited and 22 completed the study. Patients were randomized to receive either standard HPN or glutamine-supplemented HPN. Patients were assessed at randomization, 3 and 6 months later then they were crossed over to the alternative HPN and reassessed at 3 and 6 months. Assessments included plasma amino acid concentrations, intestinal permeability and absorption, nutritional status, oral and parenteral intake, quality of life, routine biochemistry and haematology. RESULTS: No difference was seen between the groups at randomization. No difference was detected between the treatment phases for infective complications (55% in the standard treatment phase and 36% in the glutamine-supplemented phase P=0.67). There were no differences in nutritional status, intestinal permeability, plasma glutamine concentrations or quality of life. CONCLUSION: Although limited by the sample size, the study has shown that glutamine as part of the nitrogen source of parenteral nutrition can be given to patients on HPN for 6 months without any adverse effects.     

Prevention of upper respiratory tract infections by gargling: a randomized trial

BACKGROUND: Gargling to wash the throat is commonly performed in Japan, and people believe that such hygienic routine, especially with gargle medicine, prevents upper respiratory tract infections (URTIs). Its effectiveness, however, has not been established by clinical trials. DESIGN: Randomized controlled trial carried out in 2002-2003 winter season and analyzed in 2003 and 2004. PARTICIPANTS: Healthy volunteers (387) aged 18 to 65 years. INTERVENTION: Participants were randomly assigned to water gargling, povidone-iodine gargling, and usual care (control). Subjects in the two gargling groups were requested to gargle with water or diluted povidone-iodine at least three times a day. Participants were followed for 60 days. MAIN OUTCOME MEASURES: The primary outcome measure was first URTI incidence. Severity of URTI symptoms among incident cases was also evaluated. Both outcomes were assessed with a self-administered symptom record. Analyses were performed on an intention-to-treat basis. RESULTS: A total of 130 participants contracted URTIs. The incidence rate of first URTI was 0.26 episodes/30 person-days among control subjects. The rate decreased to 0.17 episodes/30 person-days in the water gargling group, and 0.24 episodes/30 person-days in the povidone-iodine gargling group. Respective incidence rate ratios against controls were 0.64 (95% confidence interval [CI]=0.41-0.99) and 0.89 (95% CI=0.60-1.33). A Cox regression (proportional hazard model) revealed the efficacy of water gargling (hazard ratio=0.60, 95% CI=0.39-0.95). Even when a URTI occurred, water gargling tended to attenuate bronchial symptoms (p=0.055). CONCLUSIONS: Simple water gargling was effective to prevent URTIs among healthy people. This virtually cost-free modality would appreciably benefit the general population.