group (therefore, for vitamin E the RDA is 120 percent of the EAR). The calculated RDA in milligrams is rounded up.

In contrast to the case for most nutrients, the blood concentration of α-tocopherol increases during pregnancy, in parallel with an increase in total lipids (Horwitt et al., 1972). Placental transfer of vitamin E from mother to fetus appears to be relatively constant as pregnancy progresses (Abbasi et al., 1990). Although vitamin E deficiency can occur in premature newborns, precipitating a hemolytic anemia (Oski and Barness, 1967; Ritchie et al., 1968), there are no reports of vitamin E deficiency during pregnancy and no evidence that maternal supplementation with vitamin E would prevent deficiency symptoms in premature offspring. Given the absence of data, it would appear that vitamin E supplementation of pregnant females is unwarranted.

Since there is no evidence at this time that the EAR for women during pregnancy should be increased above the level recommended for women in the nonpregnant state, the EAR for pregnancy is assumed to be the same and thus is 12 mg (27.9 µmol)/day of tocopherol.

The RDA for vitamin E is set by assuming a coefficient of variation (CV) of 10 percent (see Chapter 1) because information is not available on the standard deviation of the requirement for vitamin E; the RDA is defined as equal to the EAR plus twice the assumed CV