Relationship between dietary, serum, and tissue levels of carotenoids.

A study was undertaken to assess the utility of the buccal scrape technique for measuring tissue levels of carotenoids in short-term intervention trials and epidemiologic studies. In 14 healthy volunteers a good correlation was found between serum beta-carotene levels and recent dietary intake of beta-carotene as estimated from measured food records. Supplementation with 30 mg/day of beta-carotene for 1 week resulted in a sixfold increase in average serum levels, while serum lycopene concentrations remained constant. Presupplementation levels of beta-carotene and lycopene in the buccal mucosa cells were not correlated with dietary intakes or with serum levels. After supplementation, levels of both carotenoids were found to increase in buccal cells, however, most of this increase was found to be an artifact due to repeated sampling. After correcting for this artifact, beta-carotene was found to increase less than twofold in tissue after supplementation.