IN A PREVIOUS communication1 we reported that the concentration of vitamin A in the blood decreases during the last trimester of pregnancy. Thus, the mean value of the concentration in the plasma of vitamin A in 70 women, six months pregnant or less, was 105.4 U.S.P. units per hundred cubic centimeters, whereas the mean value in 62 patients in the third trimester was 91.1 U.S.P. units per hundred cubic centimeters. On the other hand, there was no significant drop in the concentration of carotene in the plasma during the last three months of pregnancy.
In 9 of 12 women for whom the levels of vitamin A in the blood were determined both early and late in pregnancy, the concentration of vitamin A in the plasma diminished; the decreases ranged from 8 to 88 units. No definite correlation could be ascertained between the fall in vitamin A in the blood