Carotenoids, tocopherols, and retinoids in human buccal mucosal cells: intra- and interindividual variability and storage stability.

The baseline, intra-, and interindividual variability as well as storage stability of carotenoids, tocopherols, and retinoids in human buccal mucosal cells were determined because this information is lacking. All the buccal mucosal cell samples were collected after an overnight fast. In the variability study, 154 subjects (median age 57.5 y) provided three samples each at 7-10-d intervals over a 1-mo period. In the stability study, 13 young volunteers provided four samples each before and during the 11 d of oral administration of beta-carotene, alpha-tocopherol, and vegetable juice; the cells were pooled and stored as a pellet at -80 degrees C. Eleven micronutrients were analyzed simultaneously with HPLC. The results indicated that 1) lycopene and beta-carotene were the two major carotenoids, retinol was not detected in most cell samples; 2) the intra-individual variability was small, but the interindividual variability was very large; 3) two measurements of micronutrient concentration in fasting buccal mucosal cells should be adequate to establish a representative baseline for each micronutrient; and 4) the micronutrients under the storage conditions were stable for > or = 8 mo.