The Claim

Supplementation with 6 mg/day of lutein from marigold extract for 15 days increases serum zeaxanthin by approximately 1.7-fold in healthy adults, despite the supplement containing only low concentrations of zeaxanthin.

Source: Bioavailability of Lutein from Marigold Flowers (Free vs. Ester Forms): A Randomised Cross-Over Study to Assess Serum Response and Visual Contrast Threshold in Adults

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
68score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

Taking 6 milligrams of lutein from marigold extract daily for 15 days raises the level of zeaxanthin in the blood by about 1.7 times in healthy adults, even though the supplement contains very little zeaxanthin.

See the scientific wording

Supplementation with 6 mg/day of lutein from marigold extract for 15 days increases serum zeaxanthin by approximately 1.7-fold in healthy adults, despite the supplement containing only low concentrations of zeaxanthin, suggesting cross-absorption or metabolic conversion.

Why this might work

The body converts lutein into zeaxanthin after absorption, which raises zeaxanthin levels in the blood even when the supplement has almost no zeaxanthin to begin with.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Bioavailability of Lutein from Marigold Flowers (Free vs. Ester Forms): A Randomised Cross-Over Study to Assess Serum Response and Visual Contrast Threshold in Adults

    Taking a daily lutein supplement for two weeks made the level of zeaxanthin in the blood go up by 70%, even though the supplement had almost no zeaxanthin in it. This means your body probably turns some of the lutein into zeaxanthin.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.