[Relationship between volume and concentrations of various components of breast milk in early and 2-6 months lactation].

: The concentrations of total protein, fat, lactose, calcium and s-IgA in human colostrum and matured milk and 24-hour milk production for the same day were measured on 99 and 47 lactating women at 5 days and 2-6 months post-partum, respectively. Relationships between measured concentrations, calculated energy content, and milk volumes were investigated. 1. In colostrum, the concentrations of protein and s-IgA showed significant negative correlations with milk volumes, while those of fat and lactose, and energy content showed significant positive correlations with milk volumes. 2. In matured milk, the concentrations of protein and s-IgA showed significant negative correlations with milk volumes. However, the negative correlation between protein concentration and milk volumes was not statistically significant when subjects were limited to mothers breast-feeding only. In matured milk fat, lactose and calcium concentrations, and energy content were not significantly correlated with milk volume.