Beta-Carotene, vitamin A, and lung cancer chemoprevention: results of an intermediate endpoint study

Am J Clin Nutr. 1995 Dec;62(6 Suppl):1431S-1438S. doi: 10.1093/ajcn/62.6.1431S.


A randomized, placebo-controlled clinical trial of beta-carotene and retinol was conducted with 755 former asbestos workers as study subjects. The targeted endpoint for the intervention study was a reduction in the incidence and prevalence of sputum atypia. The dosage of 50 mg beta-carotene/d and 25,000 IU retinol/d on alternate days resulted significant increases in serum concentrations of both agents with no clinically significant toxicity. Skin yellowing was observed in approximately 35% of patients and may have contributed adversely to protocol adherence. Baseline analysis revealed that smoking and drinking were associated with lower concentrations of serum beta-carotene, even after dietary carotene intake was adjusted for (P < 0.0001). Baseline concentrations of retinol were apparently lowered by smoking (P < 0.002) and increased by drinking (P < 0.0001). Drinking and smoking also were significantly related to lower beta-carotene concentrations after supplementation (P < 0.001). No significant reduction in sputum atypia was observed after treatment.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Antioxidants / therapeutic use*
  • Carotenoids / adverse effects
  • Carotenoids / blood
  • Carotenoids / therapeutic use*
  • Double-Blind Method
  • Female
  • Humans
  • Lung Neoplasms / prevention & control*
  • Male
  • Middle Aged
  • Vitamin A / adverse effects
  • Vitamin A / blood
  • Vitamin A / therapeutic use*
  • beta Carotene


  • Antioxidants
  • beta Carotene
  • Vitamin A
  • Carotenoids