Ferritin levels in human milk.

Ferritin was detected and quantitated in breast milk from 24 mothers of healthy fullterm infants 3 days, 7 days, 6 weeks and 3 months after delivery. Highest concentrations were found at day 3 and demonstrated a marked decline at day 7, with negligible levels at 6 weeks and 3 months. The values in breast milk were compared with mother's serum ferritin concentration at delivery and a significant but weak correlation (r = 0.475, P less than 0.05) was found between the paired values of maternal serum ferritin at delivery and breast milk ferritin at day 3. The possible biological significance of ferritin in breast milk is discussed.