Postnatal tocopherol requirements have remained controversial. To study tissue uptake of α and γ tocopherol we have measured the concentration difference between paired samples of umbilical vein and artery blood (confirmed by blood gas analysis) obtained from the placenta immediately after uncomplicated term delivery (n=8). Measurements were made by HPLC techniques in light protected and deep frozen samples of plasma. Concentration of both α and γ tocopherol was higher in the umbilical vein than in the umbilical artery except for one instance for γ tocopheral in which vein and artery concentrations were identical. As shown in thefigure, the magnitude of the UV/UA difference was significantly correlated with concentration in the umbilical vein but varied widely between babies. Assuming an umbilical blood flow of 100 ml/kg/minute, a HCT of 50% and nonparticipation of the RBC in tissue uptake, estimated mean delivery to the tissues of total tocopherol was 66 mg/kg/day (Range 14 to 140). This represents a higher availability of tocopherol during the time of rapid intrauterine growth than is provided by routine oral or paren-teral feedings after delivery. Effects of stress of labor on measured UV/UA gradients are not known. Conclusions: On the basis of this data, optimal tocopherol intake after birth for growing preterm and term infants has probably been underestimated. A larger mother/infant population needs to be studied.

figure 1

Figure 1