Penelope Nestel

Vitamin A supplementation and child survival

Previous studies of the effect of 6-monthly vitamin A supplementation on child mortality have given conflicting results. In other trials, more frequent doses of vitamin A have significantly reduced mortality among children at risk of vitamin A deficiency. We have done a double-blind, placebo-controlled trial of vitamin A supplementation in the Sudan among 28,753 children aged 9-72 months at risk of vitamin A deficiency. Children were assigned to receive either 200,000 IU vitamin A and 40 IU vitamin E every 6 months (vitamin A group) or 40 IU vitamin E alone (placebo group). During the 18 months of follow-up, there were 120 deaths (8.4/1000) in the vitamin A group and 112 (7.9/1000) in the placebo group (relative risk 1.06, 95% confidence interval 0.82-1.37). Controlling for geographic site, round of observation, anthropometry, morbidity, dietary intake of vitamin A, sex, and all baseline differences between the two groups did not change the results. Children living in poor and unsanitary environments, younger children, and those sick, stunted, wasted, or consuming diets low in vitamin A were at a significantly higher risk of dying. The lack of an effect of large-dose vitamin A supplementation on mortality, despite a clear association between dietary vitamin A and mortality, underscores the need to identify factors that modify the efficacy of vitamin A supplements as a public-health measure. Reducing poverty, improvements in sanitation, and access to adequate diets should remain the main goals to improve child survival.

Undernutrition in relation to childhood infections: a prospective study in the Sudan.

Objective: The aim of the study was to examine the relationships between nutritional status and diarrhoea and respiratory infections.Design: Prospective cohort study within the framework of a randomized double-blind placebo-controlled intervention trial.Setting: In rural communities in the Khartoum and Gezira regions, in Northern Sudan.Subjects: 28, 753 Sudanese pre-school children between 6 months and 6 y old.Methods: Relative risks of subsequent diarrhoea and respiratory infections in relation to nutritional status measured by anthropometry (Z-scores of height-for-age (H/A), weight-for-height (W/H), and weight-for-age (W/A), which reflect stunting, wasting and underweight, respectively) were estimated using odds ratios from logistic regression adjusting for various covariates.Results: H/A, W/H and W/A were significantly and inversely associated with subsequent diarrhoea and febrile diarrhoea (P for trend <0.001) with risks being 2.00 times higher (95% confidence interval, CI (1.64, 2.43)) among children with W/A Z-scores below −4 Z, and 1.75 times higher (95% CI (1.56, 1.96)) among those with a W/A Z-score between −4 and −3 Z compared with children having a W/A Z-score ≥1. Age, gender, region of residence and seasonality modified these associations. Also, febrile cough was inversely associated with W/A and W/H (P<0.03), with risks ranging from 1.41 times higher (95% CI (1.02, 1.97)) to 1.21 times higher (95% CI (1.04, 1.41)) in the group of underweight children with W/A Z-scores below −4 and between −2 and −1 Z, all compared with normally nourished children (≥−1 Z).Conclusions: The reduction of severe but also mild and moderate undernutrition is necessary through nutrition, health and socio-economic improvement in order to prevent morbidity.Sponsorship: This study was carried out under cooperative agreement no. DAN-00450G-SS-6067 of the Office of Nutrition, US Agency for International Development, Washington DC, and the Harvard Institute for International Development.European Journal of Clinical Nutrition (2000) 54, 463–472

Undernutrition and childhood infections: a prospective study of childhood infections in relation to growth in the Sudan.

The relationships between both diarrhoea and respiratory infections and linear and ponderal growth were prospectively examined among 28 753 Sudanese pre‐school children. Childhood infections were significantly and inversely associated with attained height and attained weight and gain in height and weight over a 6‐mo period. They were significantly and positively associated also with stunting after adjusting for age, gender, socio‐economic status, dietary variables and previous morbidity. Attained height was on average 17 mm lower (95% CI [‐19 ‐151) for children with diarrhoea and 11 mm lower (95% CI [‐3 ‐91) for children with complicated cough than for those without these symptoms. The association between morbidity and attained weight was significant for diarrhoea and complicated cough, but the differences between children with and without symptoms were negligible. The risk of being stunted 6 mo later was 1.38 times (95% CI [1.20 1.59]), 1.29 times (95% CI [0.97 1.721) and 1.32 times (95% CI [1.13 1.541) greater among normally‐nourished children with diarrhoea, febrile diarrhoea and fever, respectively, than among children without these symptoms. The difference in attained height between children with diarrhoea or complicated cough and those without symptoms increased with age, and was larger among the non‐breastfed children compared with breastfed children.