Serum retinol, iron status and body composition of lactating women in Nandi, Kenya

Maternal vitamin A and iron status was investigated among lactating mothers in a rural community in Kenya. The aim of the study was to establish the prevalence and the relationship of these key nutrients to maternal body composition.

Eighty-eight mothers provided samples of breast milk and blood for determination of breast milk vitamin A, serum retinol and ferritin. Estimators of body composition were based on the mother's weight, height and skinfold measurements.

A total of 78.1% women had breast milk retinol <1.05 micromol/l with 38 and 62% having lactated for a period of <4 and >4 months, respectively. Prevalence of severely deficient serum retinol <0.35 micromol/l and ferritin <12 microg/l was 10 and 37%, respectively. Women with serum ferritin <12 microg/l had significantly lower average hemoglobin (p < 0.01), hematocrit (p < 0.01) and serum retinol (p < 0.05). Serum retinol of mothers who had lactated for <4 months was significantly but negatively correlated with total body fat (r = -0.40; p < 0.05). With a lactation period of >4 months a close relationship was found between serum retinol and hemoglobin (r = 0.26; p <0.01), serum retinol and serum ferritin (r = 0.20; p < 0.05), and fat free mass significantly but negatively correlated with breast milk fat (r = -0.27; p < 0.05). Serum retinol in combination with hematocrit significantly affected both maternal hemoglobin (p < 0.01) and serum ferritin (p < 0.01).

A high prevalence of vitamin A and iron deficiency was observed in this group of lactating women. Low levels of fat mass were directly related to these indicators of malnutrition.