Intake of β-cryptoxanthin with fat-containing food increases β-cryptoxanthin serum level and palmar yellowness in healthy adults

Epidemiological and clinical studies have suggested that β-cryptoxanthin (β-CX) has health benefits in humans. To understand the health benefits of β-CX, it is important to examine its in vivo kinetics and identify a convenient noninvasive biomarker for serum β-CX level. However, to date, there have been few studies of β-CX kinetics in humans. We hypothesized that simultaneous consumption of fat-containing food would stimulate absorption of β-CX. We conducted 2 in vivo kinetics studies, one after a single intake and the other after daily intake of β-CX in healthy adults, to examine whether simultaneous consumption of fat-containing food stimulates absorption of β-CX and whether palmar b* value (yellowness) is a suitable biomarker. After a single intake of 1.1 or 2.2 mg of β-CX, the serum level increased dose-dependently and returned to the baseline level after 14 to 17 days. The simultaneous consumption of fat-containing food enhanced the absorption of β-CX by 1.8-fold. During daily intake of 2.0 mg/day β-CX with fat-containing food for 12 weeks, both serum β-CX level and palmar b* value measured with a colorimeter increased continuously. After intake was halted, both serum β-CX level and palmar b* value decreased. There was a positive correlation between serum β-CX level and palmar b* value during the trial (R = 0.55, P .001). These results suggest that intake of β-CX with fat-containing food stimulates the absorption of β-CX and increases palmar yellowness.