Vitamin A

What it is and how it works

Vitamin A (retinol) is essential for vision (as a component of rhodopsin), maintenance and differentiation of epithelial tissues, immune function, growth and reproduction. Topically in the eye it supports conjunctival and corneal epithelial health and mucus production.

Indications

Prevention and treatment of vitamin A deficiency, including xerophthalmia and night blindness; supplementation in measles and in malabsorption states (e.g. cholestasis, cystic fibrosis); ophthalmic ointment for protection and lubrication of the ocular surface in dry eye and corneal epithelial disorders.

Dosage and administration (summary)

Oral or parenteral dosing depends on the indication, age and degree of deficiency (e.g. high single doses according to WHO schedules for xerophthalmia and measles, lower daily doses for prevention); ophthalmic ointment is applied to the conjunctival sac several times daily.

Contraindications

Hypervitaminosis A; hypersensitivity to the product; high-dose systemic preparations in pregnancy (except under specialist guidance for deficiency).

Warnings and precautions

Excessive intake causes acute or chronic toxicity (raised intracranial pressure, headache, liver damage, bone and skin changes); account for intake from all sources, including retinoids. Use with caution in hepatic and renal impairment. Ophthalmic ointment may cause temporary blurred vision.

Pregnancy

High doses are teratogenic; in pregnancy supplementation should not exceed recommended daily amounts unless deficiency is confirmed.

Storage and supply

Store below 25 °C, protected from light and air.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.