The Claim
In two healthy adult humans, daily supplementation with 10,000 IU of vitamin A for approximately 21 days was associated with a lower ratio of labeled retinyl ester to beta-carotene concentrations during the absorptive phase after ingestion of [14C]beta-carotene, indicating reduced cleavage of beta-carotene into vitamin A.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Taking a lot of vitamin A every day for about three weeks might make your body break down beta-carotene (from food) into vitamin A less efficiently.
See the scientific wording
In two healthy adults, vitamin A supplementation at 10,000 IU/day for about 21 days was associated with a lower ratio of labeled retinyl ester to beta-carotene concentrations during the absorptive phase following ingestion of [14C]beta-carotene, suggesting reduced cleavage of beta-carotene into vitamin A.
What the research says
1 studyThe study found that when people took vitamin A supplements, their bodies broke down less beta-carotene into vitamin A, which is exactly what the claim says.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.