Epidemiology of vitamin a deficiency in selected vulnerable population groups of Bangladesh

Abstract

A prospective study was carried out among the population groups ‘at-risk’ in four different
agro-ecologicai regions and two urban slums of Bangladesh. Following multistage sampling
technique, sixty households having at least one child from 2-5 years were selected
purposively from among the landless or marginally landholding groups in each location. Data
on food intake (24 hour recall and food frequency questionnaire) and clinical examinations
were collected in two different seasons, namely rainy season (June-July) and winter
(December-January). Poor intake of energy and nutrients were observed among the studied
population. Almost all vitamin A was provided by vegetable sources. Total intake of vitamin
A was significantly higher (p < 0.05) in the rainy season in all the locations excepting the
Lower Ganges Flood Plain, where a higher but statistically non significant intake was
observed in winter (p > 0.05). Mean usual pattern of food (UPF) score of the observed
children was significantly higher in the rainy season in all rural locations (p < 0.05). Such
seasonal differences were not found in the urban locations. A shift in UPF score distribution
toward high-risk category in the winter was observed in the rural locations and also in slum in
Dhaka. Children with xerophthalmia were detected in 3 rural locations and in the slum in
Chittagong, and it was higher in the rainy season. No cases of xerophthalmia were found in
the coastal district of Patuakhali and slum in Dhaka. Prevalence of infectious diseases was
higher in the rainy season, and most of the xerophthalmia affected children were found to
have suffered from diarrhoea, dysentery, or measles before developing ocular signs.
Seasonality and geographical variation in availability and intake of vitamin A rich food
sources and prevalence of xeropthalmia were markedly observed. Children in the coastal
region did not manifest any sign of vitamin A deficiency probably due to easy availability of
small fishes.