Vitamin A
VitaminsKey Benefits
How It Works
Retinol (active vitamin A) binds to RAR and RXR nuclear receptors, directly regulating gene transcription for over 500 genes. Essential for rhodopsin synthesis (night vision), epithelial cell differentiation, T-cell maturation, and embryonic development.
Dosage & Timing
Recommended Dosage
2,500-5,000 IU daily (do not exceed 10,000 IU)
Best Time to Take
With a fat-containing meal for absorption
Recommended Form
Retinyl palmitate or mixed carotenoids (safer)
Side Effects
Fat-soluble: TOXIC in excess. Headaches, nausea, liver damage, birth defects at high doses. Never exceed recommended intake.
Drug Interactions
Competes with vitamin D for receptor binding. Interacts with retinoids, blood thinners, and hepatotoxic drugs.
What Does The Research Say?
Essential nutrient with well-established roles. Beta-carotene (provitamin A) is safer but converts variably. Preformed retinol needed for those with poor conversion genetics (BCO1 polymorphism). Do not over-supplement.
Where to Buy
Buy Vitamin A on Amazon
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This information is for educational purposes only and does not constitute medical advice. Researched by The NexoraOS Team, supplement user since 2018. Always consult a qualified healthcare professional before starting any supplement. Individual results may vary. Amazon links are affiliate links.