Vitamin A Side Effects

Medically reviewed by Drugs.com. Last updated on May 16, 2024.

Applies to vitamin a: capsule, capsule liquid filled, solution, tablet.

Precautions

Vitamin A is stored in the body; therefore, when you take more than the body needs, it will build up in the body. This may lead to poisoning and even death. Problems are more likely to occur in:

• Adults taking 7500 RE (25,000 Units) a day for 8 months in a row, or 450,000 RE (1,500,000 Units) all at once; or
• Children taking 5400 RE (18,000 Units) to 15,000 RE (50,000 Units) a day for several months in a row, or 22,500 RE (75,000 Units) to 105,100 RE (350,000 Units) all at once.
• Pregnant women taking more than 1800 RE (6000 Units) a day.

Remember that the total amount of vitamin A you get every day includes what you get from foods that you eat and what you take as a supplement.

High doses and/or prolonged use of vitamin A may cause bleeding from the gums; dry or sore mouth; or drying, cracking, or peeling of the lips.

Serious side effects of vitamin a

Along with its needed effects, vitamin a may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking vitamin a:

• Bleeding from gums or sore mouth
• bulging soft spot on head (in babies)
• confusion or unusual excitement
• diarrhea
• dizziness or drowsiness
• double vision
• headache (severe)
• irritability (severe)
• peeling of skin, especially on lips and palms
• vomiting (severe)

Check with your doctor as soon as possible if any of the following side effects occur while taking vitamin a:

• Bone or joint pain
• convulsions (seizures)
• drying or cracking of skin or lips
• dry mouth
• fever
• general feeling of discomfort or illness or weakness
• headache
• increased sensitivity of skin to sunlight
• increase in frequency of urination, especially at night, or in amount of urine
• irritability
• loss of appetite
• loss of hair
• stomach pain
• unusual tiredness
• vomiting
• yellow-orange patches on soles of feet, palms of hands, or skin around nose and lips

For healthcare professionals

Applies to vitamin a: intramuscular solution, oral capsule, oral liquid.

Metabolic adverse events

• Frequency not reported: Hypervitaminosis A syndrome^[Ref]

Hypervitaminosis A:

General manifestations: fatigue, malaise, lethargy, abdominal discomfort, anorexia, vomiting.

Specific manifestations:

Skeletal: hard tender cortical thickening over the radius and tibia, migratory arthralgia, slow growth, premature closer of the epiphysis leading to arrested bone growth in children

Central nervous system: irritability, headache, increased intracranial pressure manifested by bulging fontanels, papilledema, and exophthalmos

Dermatologic: fissures of the lips, drying and cracking of the skin, alopecia, scaling, massive desquamation, increased pigmentation

Systemic: hypomenorrhea, hepatosplenomegaly, hepatotoxicity, jaundice, leukopenia, vitamin A plasma level over 1200 Units/mL^[Ref]

Other

• Frequency not reported: Acute toxicity (single dose of 25,000 Units/kg), chronic toxicity (4000 Units/kg for 6 to 15 months)^[Ref]

Acute toxicity occurs at single doses of 350,000 units for infants and at over 2 million units for adults.

Chronic toxicity occurs in infants (3 to 6 months) at 8,500 Units per day for 1 to 3 months, and in adults at 1 million Units daily for 3 days, at 500,000 Units daily for 2 months, or 50,000 units daily for over 18 months.^[Ref]

Hypersensitivity

• Frequency not reported: Anaphylactic shock and death (intravenous)^[Ref]

See also:

Frequently asked questions

• What are antioxidants and should you take supplements?

Further information

Vitamin a side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer