Effect of supplemental beta-carotene on plasma concentrations of carotenoids, retinol, and alpha-tocopherol in humans.
High doses of beta-carotene, a lipid-soluble nutrient, may affect the plasma concentrations of other lipid-soluble nutrients. The purpose of this study was to assess the effects of long-term daily supplementation with beta-carotene (50 mg/d) on circulating concentrations of other carotenoids, retinol, and alpha-tocopherol over time. Data were available from 259 men and women participating in the Carotene Prevention Trial, a 2-center chemoprevention trial designed to determine whether supplemental beta-carotene can prevent second malignant tumors in patients cured of an early stage cancer of the oral cavity, pharynx, or larynx. Up to 2 blood samples were obtained before the intervention (before and after a 1-mo placebo run-in), with postrandomization samples obtained at 3, 12, 24, 36, 48, and 60 mo. Supplementation with beta-carotene produced a persistent 9- to 10-fold increase in median plasma beta-carotene concentrations (225 nmol/L at baseline to 2255 nmol/L at 3 mo) and a persistent 2-fold increase in median plasma alpha-carotene concentrations (45 nmol/L at baseline to 95 nmol/L at 3 mo). Concentrations of retinol, alpha-tocopherol, lycopene, and lutein/zeaxanthin were not affected by supplemental beta-carotene. Up to 5 y of daily supplementation with beta-carotene increased circulating concentrations of alpha- and beta-carotene, but did not alter concentrations of lycopene, lutein/zeaxanthin, retinol, or alpha-tocopherol.
Mayne
S T
ST
Department of Epidemiology, Yale University School of Medicine, New Haven, CT 06520-8034, USA. Susan.Mayne@Yale.Edu
Cartmel
B
B
Silva
F
F
Kim
C S
CS
Fallon
B G
BG
Briskin
K
K
Zheng
T
T
Baum
M
M
Shor-Posner
G
G
Goodwin
W J
WJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002338:Carotenoids / Q000097:blood*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D014801:Vitamin A / Q000097:blood*; D014810:Vitamin E / Q000097:blood*; D019207:beta Carotene / Q000008:administration & dosage* / Q000627:therapeutic use
D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids