Transfer of ascorbic acid and/or its derivatives from maternal blood into the fetus was studied
during the last week of gestation in the rat. Rats were injected intravenously with [1-14 C]-
ascorbic acid and the rate of transfer estimated by the concentration and content of label
present in placentas and fetuses. At all times studied the concentration of label in the
placenta was greater than in the fetus. The highest capacity of the placenta to concentrate
label was found on day 15 decreasing to a low at day 19 and again increasing up to day 21 …