High-doses of beta-carotene (BC), a lipid-soluble nutrient, could potentially 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 BC (50 mg/day) on circulating levels of other carotenoids, retinol (A) and alpha-tocopherol (E). Data were available from 259 men and women participating in the Carotene Prevention Trial, a two center chemoprevention trial designed to determine whether or not supplemental BC could 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-month placebo run-in), with post-randomization samples obtained at 3, 12, 24, 36, 48, and 60 months. Bloods were analyzed by HPLC in 1 laboratory. Median nutrient levels (μg/mL) at baseline in the group randomized to receive BC were as follows (placebo group nearly identical): BC 0.12: A 0.48; E 12.2; alpha-carotene (AC) 0.024; lycopene (128; lutcin+zeaxanthin (L/Z) 0.14. Supplementation with BC produced a persistent 9 to 10-fold increase in median plasma BC levels (1.2 μg/mL at 3 months), and a persistent 2-fold increase in median plasma AC levels (0.051 μg/mL at 3 months). Concentrations of A, E, lycopene and L/Z were not affected by supplemental BC. Up to 5 years of daily supplementation with BC increases circulating levels of AC and BC, but does not alter levels of lycopene, L/Z, A, or E. CA 42101; CA 64567.
|Original language||English (US)|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Molecular Biology