Vitamin E and relationships among tocopherols in human plasma, platelets, lymphocytes, and red blood cells.

Plasma, RBC, platelets, and lymphocytes from human subjects on graded intakes of vitamin E were analyzed for tocopherols to determine which humoral compartment most closely followed changes in the dietary intake. Relative merits of the various blood elements to reflect changes in vitamin E intake were calculated by the sensitivity concept of Mandel and Stiehler (ie, rate of change of tocopherol levels with dose divided by the standard deviation). Sensitivities of alpha-tocopherol levels of the various blood components to vitamin E intake decreased in the order platelets greater than RBC greater than plasma lipids greater than plasma greater than lymphocytes. Changes in tocopherol levels in platelets most closely followed changing dietary intakes of vitamin E when compared with data from RBC, lymphocytes, and plasma. Furthermore, for studying the effects of diets on vitamin E status, tocopherol levels of platelets appear to be a better measure than tocopherol levels of either RBC, lymphocytes, or plasma lipids.