Sialic Acid and Iron Content in Breastmilk of Chinese Lactating Women

Objective: To study sialic acid and iron content in breastmilk in Chinese women during different lactation stages. Methods: Sialic acid and iron content of colostrum, transitional milk, mature milk, and involutional milk were determined using a neuraminidase assay kit and the ferrozine method, respectively in 88 lactating women (58 Term, 30 Preterm). Results: The mean (SD) sialic acid levels of colostrum, transitional milk, mature milk, and involutional milk were 2201.4 (676.6) mg/L, 1445.9 (423.4) mg/L, 395.3 (96.0) mg/L and 273.0 (76.9) mg/L, respectively. The median iron content were 0.05 mg/L, 0.06 mg/L, 0.25 mg/L and 0.35 mg/L, respectively, in successive stages of lactation. Sialic acid and iron were significantly higher in breast milk of preterm mothers compared to term mothers. Conclusion: Sialic acid and iron content in breast milk vary greatly throughout the lactation stages, which probably reflects the infants' needs for growth and development at different stages.