Zinc levels in the Nigerian full-time newborn from birth to six months

Zinc(Zn) remains an important micronutrient needed by the growing foetus and newborn. We are unaware of a previous study delineating the longitudinal evolution in the African fullterm (FT) infant. Hence we prospectively studied thirty randomly selected stable FT infants (M:F; 17:13) born between July 1991 and April, 1992. Serum Zn was determined by atomic absorption spectrophotometry on unhaemolysed sera. Eighty per cent of the babies were exclusively breastfed up to the age of six months. The mean birthweight was 3490 g(range, 2950-3950) with a mean gestational age 39.7 weeks(range, 38-42). The cohort included two sets of twins. Mean (SD) serum zinc was 2.4 (0.2) mumol/ml at birth and declined significantly (p < 0.01) over the subsequent eight weeks to a nadir of 1.2 (0.2)mumol/ml. Levels later rose to 1.6(0.3)mumol/ml at 12 weeks whilst peaking 2.2(0.3)mumol/ml in 16 weeks. It remained fairly constant at 2.0(0.2) and 2.1(0.2)mumol/ml between 20 and 24 weeks, respectively. The zinc evolution had a triphasic pattern. Our trend compare favourably with previous literature from affluent societies, but our levels were one and a half to two fold higher. The findings may serve as normative reference against which serum zinc concentration in the African infant could be compared. Our findings(number albeit small) could be taken as a preliminary report.