Vitamin A
Indications
Vitamin A (retinol) is used to prevent and treat vitamin A deficiency, which causes night blindness, dry eyes that can lead to blindness, dry rough skin and a higher risk of infections. Health programmes give high-dose vitamin A to young children to prevent deficiency, and doctors give it to children with measles to lower the risk of complications. It is also part of many multivitamin products.
How It Works
Vitamin A is needed to make the light-sensitive pigment in the eye that allows vision in dim light. It keeps the surface of the eyes, skin and the lining of the airways and gut healthy, and supports the immune system and growth.
Dosage and Administration
- Adults, supplement: only as advised by a doctor. Total vitamin A from all supplements should generally stay below 10,000 IU a day.
- Treatment of deficiency or eye disease: as prescribed.
- Children, including high-dose capsules given in health programmes and measles treatment: as prescribed by the health worker or doctor.
Take with food. Do not combine several products that contain vitamin A without advice.
Interactions
- Do not take with Isotretinoin, Acitretin or other retinoid medicines, as the effects add up and can be toxic.
- With Tetracycline, Doxycycline or Minocycline, high doses may raise pressure around the brain.
- High doses may increase the effect of Warfarin.
- Orlistat, Cholestyramine and liquid paraffin reduce absorption.
Contraindications
- Allergy to vitamin A or any ingredient of the product.
- Too much vitamin A in the body (hypervitaminosis A).
- High doses in pregnancy or in women who may become pregnant.
- Use with retinoid medicines such as Isotretinoin.
Side Effects
Normal doses rarely cause side effects. Too much vitamin A, taken at once or over time, can cause headache, nausea, vomiting, drowsiness, dry or peeling skin, hair loss, bone or joint pain and liver damage. In infants it can cause a bulging soft spot on the head. Get urgent medical help if you notice a severe headache, blurred or double vision, repeated vomiting, unusual drowsiness or confusion, yellow skin or eyes, or a serious allergic reaction.
Pregnancy and Lactation
High doses in pregnancy can cause serious birth defects. Pregnant women and women who may become pregnant should not take more than 10,000 IU a day from supplements, and only take vitamin A if a doctor advises it. Normal doses are safe during breastfeeding; avoid high doses unless advised.
Precautions and Warnings
Avoid long-term high doses. Check all your supplements and multivitamins for vitamin A content, as amounts add up. Tell the doctor if you have liver disease or drink alcohol heavily, as the liver is more easily harmed.
Overdose
A large overdose can cause severe headache, dizziness, drowsiness, vomiting, blurred vision and peeling skin, and in children it can be dangerous. Seek urgent medical help.
Therapeutic Class
Fat-soluble vitamin.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.
All brands of Vitamin A