Zinc and copper levels in the breast-milk of Cape Town mothers

Zinc and copper levels were measured longitudinally in the breast-milk of 55 healthy South African women from the middle and upper socio-economic classes. The mean foremilk zinc levels showed a significant fall (P < 0,05) from 652,9±240,7 μg/dl at 3 days after delivery to 413,3±143,0 μg/dl at 7 days and 228,1±136,1 μg/dl at 6 weeks. Lower foremilk zinc levels were obtained at 36 weeks (64,3±50,0 μg/dl). In contrast, foremilk copper levels were low at 3 days (57,0±74,8 μg/dl), with a gradual decline to very low levels (28,0±29,7 μg/dl) at 36 weeks. No differences were detected between the fore- and hindmilk zinc and copper levels at any stage of lactation studied (P > 0,05).