Vitamin A

What is Vitamin A?

Vitamin A is a fat-soluble vitamin that comes in two main forms: preformed vitamin A (retinol and related forms) from animal foods and supplements, and provitamin A carotenoids, such as beta-carotene, from plant foods.^[1]

The body stores extra vitamin A, mainly in the liver.^[1]

Its role in the body

• Needed for vision, especially seeing in low light.^[1]
• Supports the immune system.^[1]
• Helps cells grow and develop normally, and supports reproduction and the health of the heart, lungs and other organs.^[1]

Important food sources

• Carrots, sweet potato, pumpkin and ripe mangoRich in beta-carotene.
• Green leafy vegetables such as spinach (palak), amaranth (chaulai), drumstick (moringa) leaves and methiProvide carotenoids.
• PapayaProvides carotenoids.
• Milk, curd, ghee, butter and eggsProvide preformed vitamin A.
• Liver (chicken, goat)Very high in preformed vitamin A; large, frequent portions can exceed the upper limit.
• Fortified foodsSome edible oils and milks are fortified with vitamin A; check the label.

Recommended dietary intake

Signs sometimes associated with low levels

• One of the first signs is difficulty seeing in dim light (night blindness). Severe deficiency can damage the eye and cause blindness.^[1]
• Deficiency increases the risk and severity of infections, such as measles and diarrhoea in children.^[1]
• Deficiency is uncommon in high-income countries but still common in some low- and middle-income countries, including in South Asia.^[1]

Why symptoms alone cannot confirm a deficiency

Signs like tiredness, weakness, hair fall or low mood are very common and have many possible causes, such as poor sleep, stress, infections, thyroid problems or other illnesses.

The same sign can come from several different nutrients, or from no nutrient problem at all.

Only a qualified clinician, using your history, an examination and, when needed, lab tests, can say whether a deficiency is present. This app cannot diagnose a deficiency from symptoms or from BMI.

Trouble seeing at night or dry eyes can be caused by many eye conditions that need an eye examination.

Tests a clinician might consider

• Blood (serum or plasma) retinol can show significant deficiency, but levels do not fall until liver stores are almost used up, so a normal result does not always rule out low status.^[1]
• Eye examination for signs such as night blindness or dryness of the eye.^[1]

Who is more likely to have low intake

• Young children and pregnant or breastfeeding women in places where vitamin A deficiency is common.^[1]
• Premature babies.^[1]
• People with cystic fibrosis or other conditions that reduce fat absorption, such as celiac disease, Crohn’s disease or some pancreatic and liver conditions.^[1]

Potential benefits and quality of evidence

• Adequate vitamin A is essential for normal vision and immune function.^[1] Established
• Diets rich in fruits and vegetables that contain carotenoids are linked with lower risk of some cancers in observational studies, but these studies cannot prove cause and effect.^[1] Limited evidence
• Beta-carotene supplements increased lung cancer risk in people who smoke or have been heavily exposed to asbestos in large trials.^[1] Established
• Specific multi-ingredient eye supplements may slow progression of advanced age-related macular degeneration in people at high risk; this is a medical decision for an eye specialist.^[1] Moderate evidence

Side effects

• High intakes of beta-carotene over a long time can turn the skin yellow-orange (carotenodermia). This is harmless and goes away when intake falls.^[1]

Risks of too much

• Very large single doses of preformed vitamin A can cause severe headache, blurred vision, nausea, dizziness and muscle aches, and in severe cases coma or death. Regular high intakes can cause dry skin, painful muscles and joints, tiredness, low mood and abnormal liver tests.^[1]
• High preformed vitamin A in pregnancy can cause birth defects.^[1]
• Beta-carotene from food is not known to be toxic, but beta-carotene supplements are not advised for the general population, and they raised lung cancer risk in smokers.^[1]

Medicine and supplement interactions

• Orlistat (weight-loss medicine): Can reduce absorption of vitamin A and beta-carotene.^[1]
• Retinoid medicines taken by mouth (such as acitretin or bexarotene): These medicines are related to vitamin A; taking them with vitamin A supplements can lead to dangerously high levels.^[1]

Never start, stop or change a prescribed medicine because of this list — talk to your doctor or pharmacist.

Pregnancy and breastfeeding

• Preformed vitamin A intake above the upper limit, and some retinoid medicines such as isotretinoin, can cause birth defects. Experts advise people who are or might be pregnant, and those breastfeeding, not to take high-dose vitamin A supplements. Very large, frequent servings of liver are also very high in preformed vitamin A; ask your doctor about this.^[1]

Kidney and liver cautions

• The upper limit for preformed vitamin A is partly based on the risk of liver damage. People with liver disease should not take vitamin A supplements without medical advice.^[1]

Upper intake limits

When to talk to a professional

Talk to a doctor or registered dietitian before starting a supplement, especially if you are pregnant or breastfeeding, have a long-term illness, or take any regular medicines.

Do not start, stop or change a prescribed medicine because of anything you read here.

Supplements sold without a prescription are not automatically safe. Doses, quality and interactions still matter.

Seek medical care promptly if you have severe, sudden or worsening symptoms.

If you are pregnant or planning a pregnancy, check any vitamin A-containing supplement with your doctor.

Still being verified

• ICMR-NIN 2020 vitamin A unit basis (retinol vs. retinol activity equivalents) to be confirmed from the full report.
• ICMR-NIN 2020 values for pregnancy/lactation and Tolerable Upper Limit not verified; not stated.

References

1. NIH Office of Dietary Supplements. Vitamin A and Carotenoids — Fact Sheet for Health Professionals (opens in a new tab) (2025-03-10). Accessed 9 Oct 2026.
2. ICMR-National Institute of Nutrition (India). A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR), ICMR-NIN, 2020 (opens in a new tab). Accessed 9 Oct 2026.

Sources checked: 9 Oct 2026