Bioavailability of carotenoids from chlorella powder in healthy subjects: A comparison with marigold petal extract

• The bioavailabilities of major carotenoids were compared in chlorella and marigold.
• Carotenoids in plasma, lipoproteins, and buccal mucosa were measured by HPLC.
• Plasma lutein was comparably high and correlated to LDL/HDL/buccal mucosa content.
• Plasma α-carotene was high for chlorella and correlated to LDL content.
• Chlorella may be used as carotenoids source with a reliable mass production.

More information on the bioavailability of carotenoids is needed to make recommendations on carotenoid consumption. Here, we compared the bioavailabilities of lutein, zeaxanthin, α-carotene, and β-carotene from regular chlorella powder (RC), lutein-enriched chlorella powder (LC), and marigold petal extract (M) in a randomised clinical trial. The plasma lutein response was highest for LC, comparably high for RC and M and was positively correlated with LDL, HDL, and buccal mucosal cell (BMC) content. The plasma α-carotene response was delayed but significant for LC and RC and was positively correlated with LDL content. The plasma zeaxanthin and β-carotene responses did not differ among the groups and were positively correlated with LDL content. Lutein and zeaxanthin were detected in BMCs, but α-carotene and β-carotene were not. These findings support the use of chlorella powder as a lutein source that is equivalent to marigold petal extract, but with a greater diversity and reliable mass-production.