IMPORTANCE OF FORMULA Ca/Pi RATIO ON CALCIUM BALANCE IN THE LOW BIRTHWEIGHT INFANTS DURING THE FIRST THREE DAYS OF LIFE

Abstract

Twenty four healthy low birthweight infants were placed into three groups according to the formula fed. Group 1(10 infants) received a formula with a Ca/Pi ratio of 2.4 .Group 2 (9 infants) a Ca/Pi ratio of 1.6 and Croup 2s the same formula as Group 2 but supplemented with calcium lactate giving off a Ca/Pi ratio of 4.2 . All ratios were obtained after 78 determinations of formula feedings. Pi content in Group 1 formula was significantly lower (p < 0.01) than in Group 2 and 2s. No differences (F) were detected in the neonatal status. Calcium retention (mg/Kg/d) was significantly higher (p < 0.05) in Group 1 than in Group 2 (50.8±15.9 versus 39.3±12.8) but lower than in Group 2s (107.7±25.6 ; p < 0.001).Magnesium retention was 5.6±2.3; 4.6±1.8 and 5.6±2.1 respectively with no significant differences. Pi retention was significantly higher (p < 0.01) in Group 2 (39.2±5.2) than in both Group 1 (31.4±5.6) and Group 2s (31.9±3.6). Calcium retention correlates (r = 0.79 p < 0.001) with the real Ca/Pi ratio. Hypocalcemia appeared only in two infants from Group 2. According to these data, higher Ca/Pi ratios increase calcium and decrease Pi retention.