Evaluation of serum and tissue levels of beta-carotene.

Interest in beta-carotene (BC) has increased as studies show that low dietary or serum BC is associated with increased risk of cancer. Patients with oral epithelial dysplasia had serum and oral mucosa punch biopsy samples taken before supplementation of 30 mg/day of beta-carotene and after 6 and 9 months of supplementation. BC was analyzed for 28 patients by high-performance liquid chromatography. At baseline, serum BC and gender accounted for 48% of tissue BC variance: Tissue BC = -0.13 + 0.08(Serum BC) + 1.21(Sex) with sex as male = 0 or female = 1. Following supplementation, serum BC had an exponential relationship to tissue BC which accounted for 52% of tissue variance: Tissue BC = 1.15 + 5.7 x 10(-5)(Serum BC)2 + 3.91(Sex). Women had higher mean concentrations of serum and oral mucosal BC before and during supplementation. The need for oral mucosal sampling may be eliminated by the correlation between serum and tissue BC.