Anemia Varies with Season and is not Related to Iron Deficiency in Pre-school Children in Rural Bangladesh

Abstract

Objectives: To examine the prevalence of anemia, iron deficiency and iron deficiency anemia in pre-school children and potential seasonal variations. Methods: As part of a community-based trial in rural Bangladesh (the MINIMat-trial) children were assessed for hemoglobin and ferritin concentrations at 4.5 years. Season of blood collection were divided into 2 months categories starting with cool-and-dry season (15 Dec-14 Feb), followed by mild-temperature, hot-and-dry, monsoon-rains, hot-and-humid, and main-harvest season. We used logistic regression for associations between anemia and iron deficiency and chi-square test for seasonal differences. Results: Anemia was found in 7% of the children. Iron deficiency was low, only 3%, and consequently iron deficiency anemia was found in less than 1%. Iron deficiency was not associated with anemia, either in crude or adjusted analyses (SES, maternal education, height). Anemia varied significantly with season (p < 0.001) with the lowest prevalence found in the hot-and-humid season (4%) while anemia prevalence was about threefold in the hot-and-dry season (13%). Iron deficiency did not vary with season. Conclusions: In pre-school children in rural Bangladesh, anemia was relatively uncommon found in less than 10% of the children. A potential reason may be a relatively high iron content of drinking groundwater. The observed anemia was not associated with iron deficiency indicating the importance of other determinants. We found seasonal variations in anemia prevalence suggesting seasonal differences in diet, infections etc. as potential mechanisms in developing anemia. This also illustrates the risk of over- or under-estimating anemia if data are collected in a limited time period.