Response of whole blood, erythrocyte and plasma vitamin E content to dietary vitamin E intake in the chick

Whole blood, red blood cells (RBC), and plasma vitamin E (VE) levels in chicks fed dietary VE (dl-alpha-tocopheryl acetate, dl-alpha Ta) supplementation in steps of 0.0, 5.0, 10.0, 15.0, 20.0 and 30.0 mg/Kg were determined to examine their usefulness as an index of VE status. The increase in VE level was significant and linear in whole blood (r = 0.90), RBC (r = 0.89) and plasma (r = 0.93) in response to dietary VE intake. There was a close correlation between VE in plasma vs whole blood (r = 0.90), plasma vs RBC (r = 0.91) and whole blood vs RBC (r = 0.95). The plasma VE content was 1.2-1.8 times greater than that of whole blood, and 6.6-12.5 times greater than that of RBC. The plasma total lipids content was not affected by the dietary VE intake, whereas the level of VE in the plasma total lipids was significantly increased with increasing supplementation. Alpha tocopherol was the major isomer (ca 92%) of VE in whole blood, RBC and plasma at hatching. The small proportions of beta-tocopherol (ca 2%), gamma-tocopherol (ca 5%) and alpha-tocotrienol (ca 1%) observed at 1 day of age had decreased or totally disappeared by 7 days of age after feeding the VE-free basal diet. The data showed that in the chick, the whole blood and RBC levels of VE were as sensitive and reliable indexes of dietary VE status as was that of the plasma.