Dietary fish oil-induced changes in the distribution of alpha-tocopherol, retinol, and beta-carotene in plasma, red blood cells, and platelets: modulation by vitamin E.
Healthy men (ages 24-57 y) were fed a controlled basal diet supplemented with 15 g/d of placebo oil (PO) for 10 wk followed by 15 g/d of fish-oil concentrate (FO) (fortified with 15 mg all-rac-tocopherol) for 10 wk without additional alpha-tocopherol and the last 8 wk with 200 mg alpha-tocopherol/d (FO+E). Compared with PO, FO raised plasma malondialdehyde; lowered alpha-tocopherol in plasma, red blood cells, and platelets; and raised plasma and platelet beta-carotene. Supplementation with additional alpha-tocopherol (FO+E) not only restored tocopherol concentrations but also reversed the rise in beta-carotene. The response in retinol, particularly in platelets, showed an inverse relationship to beta-carotene, alpha-tocopherol exhibiting a modulating effect on these changes. From these observations it is postulated that platelets may be a significant extraintestinal site of retinol formation from beta-carotene.
Nair
P P
PP
Lipid Nutrition Laboratory, Beltsville Human Nutrition Research Center, USDA, MD 20705.
Judd
J T
JT
Berlin
E
E
Taylor
P R
PR
Shami
S
S
Sainz
E
E
Bhagavan
H N
HN
D000328:Adult; D001792:Blood Platelets / Q000378:metabolism; D002338:Carotenoids / Q000097:blood*; D004041:Dietary Fats / Q000008:administration & dosage; D004912:Erythrocytes / Q000378:metabolism; D005395:Fish Oils / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014801:Vitamin A / Q000097:blood*; D014810:Vitamin E / Q000097:blood* / Q000494:pharmacology*; D019207:beta Carotene
D004041:Dietary Fats; D005395:Fish Oils; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids