抄録
To examine the bioavailability of β-carotene, human young male volunteers were given daily either 60 mg of synthesized all-trans, a naturally-occuring β-carotene preparation derived from Dunaliella bardawil, or a placebo. The all-trans β-carotene levels in the subjects given the synthesized all-trans form were almost twice that for the Dunaliella preparation. The plasma 9-cis levels were found to be higher in the all-trans βcarotene group than those in the Dunaliella group, despite no intake of the 9-cis form in the all-trans group and the higher intake of the 9-cis form in the Dunaliella group. This finding suggests that isomerization of the all-trans form to the 9-cis form may occur in the body either during or after absorption. The CD4/CD8 ratio increased after 44 weeks of βcarotene administration whereas natutal killer cells, memory T cells, and cytotoxic T cells remained unaltered throughout the study.
