Abstract

Renal excretion of folate during the first 5 days of life has been measured in 10 infants of 31 to 40 weeks' gestation and compared with inulin clearance. Average daily folate loss per unit surface area (23 μg/m²) was nearly 8 times as high as in adult life and more than enough to account for the observed fall in plasma folate activity. No difference was detected between the pattern of folate excretion in preterm and term infants. Poor tubular reabsorption of filtered folate is thought to be responsible for the loss observed.