Jose O. Alvarez

Simultaneous zinc and vitamin A supplementation in Bangladeshi children: randomised double blind controlled trial

Abstract Objective: To evaluate the effect of simultaneous zinc and vitamin A supplementation on diarrhoea and acute lower respiratory infections in children. Study design: Randomised double blind placebo controlled trial. Setting: Urban slums of Dhaka, Bangladesh. Participants and methods: 800 children aged 12-35 months were randomly assigned to one of four intervention groups: 20 mg zinc once daily for 14 days; 200 000 IU vitamin A, single dose on day 14; both zinc and vitamin A; placebo. The children were followed up once a week for six months, and morbidity information was collected. Results: The incidence and prevalence of diarrhoea were lower in the zinc and vitamin A groups than in the placebo group. Zinc and vitamin A interaction had a rate ratio (95% confidence interval) of 0.79 (0.66 to 0.94) for the prevalence of persistent diarrhoea and 0.80 (0.67 to 0.95) for dysentery. Incidence (1.62; 1.16 to 2.25) and prevalence (2.07; 1.76 to 2.44) of acute lower respiratory infection were significantly higher in the zinc group than in the placebo group. The interaction term had rate ratios of 0.75 (0.46 to 1.20) for incidence and 0.58 (0.46 to 0.73) for prevalence of acute lower respiratory infection. Conclusions: Combined zinc and vitamin A synergistically reduced the prevalence of persistent diarrhoea and dysentery. Zinc was associated with a significant increase in acute lower respiratory infection, but this adverse effect was reduced by the interaction between zinc and vitamin A. What is already known on this topic Trials of vitamin A supplementation have failed to show a beneficial effect on morbidity in children Experimental studies have shown that, in the presence of zinc deficiency, vitamin A supplementation fails to reverse vitamin A deficiency Coexistence of deficiencies of zinc and vitamin A could be a reason for the failure of vitamin A supplementation, but data in humans are limited What this paper adds Combined zinc and vitamin A supplementation is more effective in reducing persistent diarrhoea and dysentery than either vitamin A or zinc alone Zinc alone increased respiratory illnesses, but interaction between zinc and vitamin A reduced this adverse effect

The relationship between maternal serum zinc levels during pregnancy and birthweight

A retrospective follow-up study to ascertain the relationship between the level of serum zinc and its rate of change during gestation and birthweight was conducted in 476 women of lower socioeconomic status. Serum zinc concentrations measured at approximately 16 (early) and 32 weeks (later) in gestation were both found to be significant predictors of birthweight. Even after controlling for gestational age at birth and other determinants of birthweight, for each microgram/dl increase in serum zinc early and later in pregnancy, birthweight increased by 5.8 and 8.6 g, respectively. Furthermore, after adjustment for initial zinc levels both the total change (beta = -7.0, P = 0.0007) and the rate of change (beta = -60.8, P = 0.007) in serum zinc during pregnancy were inversely associated with birthweight, i.e., the larger the fall in serum zinc during pregnancy, the smaller the infant. Low serum zinc level (less than 60 micrograms/dl) late in pregnancy was associated with greater than a five-fold increase in the odds (OR = 5.8, 95% CI = 1.8, 16.4) of giving birth to a low birthweight infant. The results of this study suggest a threshold for maternal serum zinc below which the prevalence of low birthweight increases rapidly.

Effect of vitamin A administration on response to oral polio vaccination

Abstract To evaluate the effect of simultaneous administration of vitamin A and Oral Polio Vaccine (OPV) on seroconversion to OPV a randomized double-blind, placebo-controlled trial was conducted. Fifty-seven infants were randomly given either 50,000 I.U. vitamin A (n=34) or placebo (n=23) with each OPV vaccine at monthly intervals. Seroconversion to polio were 81% (79% in vitamin A group and 83% in placebo group, p=0.76) for polio virus type 1, 86% (82% in vitamin A group and 91% in placebo group, p=0.34) for polio virus type 2, and 84% (82% in vitamin A group and 87% in placebo group, p=0.64) for polio virus type 3. A multiple logistic regression model was done to examine the factors associated with reduced seroconversion (polio virus type 1). For adequate vitamin A status the adjusted odds ratio of seroconversion was 0.24 (95% CI: 0.04-1.49, p=0.11) and that for high maternal antibody was 0.11 (95% CI: 0.02-0.68, p=0.015). The geometric mean titer (GMT) was significantly lower in infants with adequate vitamin A stores compared to vitamin A deficient infants (p=0.04; Mann-Whitney test). The results of this study suggest that vitamin A supplementation had no effect on seroconversion, however, in children with adequate vitamin A status there was a trend towards lower seroconversion. High maternal antibody was significantly associated with reduced seroconversion to the oral polio vaccine.

Vitamin A depletion in HIV infection and AIDS.

published by jollyp on Mon, 09/08/2014 11:41am Title Vitamin A depletion in HIV infection and AIDS. Publication Type Journal Article Year of Publication 1996 Authors Jolly, P, Yang, YL, Alvarez, JO, Smoot, TM Journal AIDS Volume 10 Issue 1 Pagination 114 Date Published 1996 Jan ISSN 0269-9370

Diet and oral premalignancy in female south Indian tobacco and betel chewers: a case-control study.

The diets of 158 tobacco/betel quid-chewing women diagnosed with oral premalignant lesions and 155 quid-chewing but lesion-free controls, frequency matched for age, tobacco/betel habits, and socioeconomic status, were assessed using a food frequency survey. Index scores generated from the food frequency survey indicated that the mean levels of consumption for foods of animal origin (p < 0.001), total vegetables and fruit (p = 0.001), vegetables alone (p = 0.006), fruits alone (p = 0.006), and green leafy vegetables (p = 0.015) were significantly lower in cases than in controls. The mean index score for cobalamin (vitamin B12) was lower in cases with a borderline significance (p = 0.05), whereas the indexes for folate and carotene were not significantly different. The analysis of index scores estimating the number of 100-g servings per week of foods of animal origin [meat, eggs, milk, curd (yogurt), fish] consumed revealed that women who ate fewer servings were more likely to have premalignant lesions than those who ate more animal foods [odds ratio (OR) 3.38, 95% confidence interval (CI) 2.07-5.54, p = 0.001]. The risk for low consumption of vegetables was not as significant as that for foods of animal origin. However, those eating low levels of vegetables and low levels of foods of animal origin were at the greatest risk for lesions (OR 5.38, 95% CI 1.72-22.17, p < 0.05). In South Indian female tobacco/betel chewers, a diet deficient in foods of animal origin appears to be a more significant risk factor for oral premalignancy than is a diet deficient in fruits and vegetables.

Subclinical vitamin A deficiency in young infants from Bangladesh

Abstract In Bangladesh, the high prevalence of clinically evident vitamin A deficiency in children under 5 years has been well documented, however, little is known about the vitamin A status of children under 1 year. The relative dose response (RDR) test was carried out in 85 healthy infants (5.9±2.3 months) coming to the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) or Dhaka Shishu Hospital for routine immunization and whose parents agreed to participate in the study. Mean serum retinol [R] was 0.66±0.3 μmol/l and mean RDR value was 29.8±22.1. Fifty-six (56%) percent of the infants had serum [R] values under 0.70 μmol/l and 18% under 0.35 μmol/l. Sixty-four percent (64%) of the infants had abnormal RDR values (≥20) indicating low liver reserves of vitamin A. These results indicate that there is a high prevalence of subclinical vitamin A deficiency in Bangladeshi infants. RDR values showed a negative correlation with weight-forage. The percentage of infants with serum retinol concentration

Intra- and Extracellular Water Dynamics on Rehydration in Cholera and Noncholera Patients

To estimate the intra- and extracellular bodywater compartments during rehydration of patients withcholera and noncholera diarrhea by bioimpedanceanalyzer, we studied 30 patients with acute waterydiarrhea. Total body water (TBW), intracellular water(ICW), and extracellular water (ECW) of severelydehydrated adult patients were measured with a dualfrequency bioimpedance analyzer at different phases ofrehydration. Fluid compartments between cholera andnoncholera patients were compared. Cholera patientsgained more TBW than noncholera patients duringrecovery. Unlike patients with noncholera diarrhea, thegain in cholera patients was mainly contributed by theICW (1.5 ± 1.6 vs 3.0 ± 1.2 liters,respectively, P < 0.01). It was also observed thatthe recovery of the ICW compartment in cholera patientsoccurred rapidly within the first 2 hr after infusion.Differential dynamics of body water compartments incholera compared to noncholera patients as observed inthis study may contribute further to understanding the mechanism of dehydration in diarrhealdisease, which might help in improving casemanagement.