Serum beta-carotene before and after beta-carotene supplementation.
A two-month double-blind, placebo-controlled supplementation study of oral beta-carotene (20 mg daily) was conducted. Two hundred and twenty two 30-69 year old men were randomized into either a beta-carotene or placebo group, and serum samples were obtained at baseline, follow-up (2 months), and up to 12 weeks post-supplementation. Serum beta-carotene increased on average 10-fold in the beta-carotene group, from 0.53 +/- 0.32 mumol/l (mean +/- SD) at baseline to 4.99 +/- 2.47 mumol/l at follow-up (P less than 0.0001), and beta-carotene levels remained elevated up to 12 weeks post-supplementation (0.61 +/- 0.15 mumol/l). No changes in serum retinol, alpha-tocopherol, or total cholesterol were observed. At baseline, serum beta-carotene levels were positively correlated with dietary beta-carotene (r = 0.29) and inversely correlated with body mass index and serum gamma-glutamyltransferase (r = -0.33 and r = -0.40, respectively). The inverse association with body mass index and serum gamma-glutamyltransferase persisted during active supplementation, whereas the positive association with dietary beta-carotene disappeared. In multivariate analysis, serum cholesterol was also positively associated with serum beta-carotene levels both before and after supplementation. Baseline serum beta-carotene was the factor most strongly associated (positively) with serum beta-carotene after supplementation. Our study highlights the importance of several factors which affect serum beta-carotene.
Division of Cancer Prevention and Control, NCI, NIH, Bethesda, MD 20892.
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Albanes
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Virtamo
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Rautalahti
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Haukka
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Palmgren
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Gref
O P
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Heinonen
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002338:Carotenoids / Q000008:administration & dosage / Q000097:blood*; D002784:Cholesterol / Q000097:blood; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000097:blood; D019207:beta Carotene; D005723:gamma-Glutamyltransferase / Q000097:blood
D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids; D002784:Cholesterol; D005723:gamma-Glutamyltransferase