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Does Grapefruit Affect Vitamin A?
Amount or timing may matter
The short answer
Retinol is partially metabolized by CYP3A4. Grapefruit may increase vitamin A levels, raising hepatotoxicity risk at higher doses.
How to arrange timing
Separate high-dose vitamin A from grapefruit by at least 4 hours.
Reference
Reference noted for this food and supplement combination: Ross AC, J Nutr 2012; Examine.com
Important context
The effect can also change with food amount, supplement dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.