Uses

Vitamin A is indicated for the prevention and treatment of vitamin A deficiency, which can manifest as night blindness and xerophthalmia. It is also used as a dietary supplement to support immune function, skin integrity, and normal vision. Supplementation is especially important in populations with inadequate dietary intake.

Do not use if

Contraindicated in patients with hypervitaminosis A. High-dose vitamin A supplementation is contraindicated in pregnancy due to teratogenic risk (doses above 10,000 IU/day). Avoid in patients with malabsorption syndromes unless under medical supervision.

Side effects

At therapeutic doses, vitamin A is generally well tolerated. Allergic rash and rare idiosyncratic reactions have been reported. Acute toxicity from very high doses causes headache, nausea, vomiting, and visual disturbances. Chronic hypervitaminosis A leads to liver damage, hair loss, bone pain, and teratogenicity.

Warnings

Keep out of reach of children. Avoid concurrent use with isotretinoin or other retinoids. Liver disease increases risk of toxicity. Doses above recommended daily allowances should only be taken under medical supervision.

How it works

Vitamin A (retinol) and its active metabolites (retinal, retinoic acid) are essential for visual phototransduction via rhodopsin regeneration, epithelial cell differentiation, immune function, and embryonic development. Retinoic acid binds nuclear receptors (RAR, RXR) to regulate gene expression.

Storage

Store in a cool, dry place protected from light. Follow manufacturer-specific storage instructions on the product label.