The effect of prolonged bottle feeding on cow's milk intake and iron stores at 18 months of age.

Thirty-four toddlers were studied in a prospective, convenience sample comparison at their 18-month health supervision visit to examine the effect of prolonged (i.e., to 18 months of age) bottle feeding on both the daily volume of cow's milk intake and the toddler's iron stores (serum ferritin concentrations.) Seventeen toddlers had been weaned from the bottle by approximately 1 year of age, and 17 toddlers who remained on the bottle at 18 months of age were the compared group. The toddlers who remained on the bottle had significantly greater (P < 0.001) cow's milk intake (mean 26.3 oz vs 16.1 oz). The mean ferritin concentrations were lower in the persistent bottle group (17.3 micrograms/L vs 23.4 micrograms/L), but not significantly so. Questioning parents about their toddlers' continued bottle use at 18 months can provide a marker for potentially excessive cow's milk intake.