Back to collection
A
Vitamins
Vitamin A (Retinyl Palmitate / Beta-Carotene)
Fat-soluble vitamin for immune function, vision, and skin health.
What it is
Vitamin A (retinol/retinyl esters) is essential for vision, immune cell differentiation, and epithelial tissue maintenance. Beta-carotene is a provitamin A.
How it works
Retinol activates RAR/RXR nuclear receptors controlling gene expression for immune function, vision (rhodopsin), and cell differentiation.
What the evidence says
Strong evidence for preventing deficiency-related issues; supplementation primarily beneficial in those with suboptimal intake.
Safety Notes
- Preformed vitamin A (retinol) can cause toxicity at high doses. Beta-carotene is safer but less potent. Smokers should avoid high-dose beta-carotene.
- Not recommended during pregnancy or while breastfeeding.
- Use caution with: pregnancy (preformed vitamin A >10,000 IU is teratogenic), active liver disease.
- retinoids (isotretinoin, tretinoin): Additive vitamin A toxicity; AVOID combining.
- anticoagulants: High-dose vitamin A may increase bleeding risk.
- tetracycline antibiotics: Concurrent use may increase intracranial pressure; avoid.