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Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid in individuals with a known hypersensitivity or allergy to vitamin A or any component of the formulation.

Side Effects and Warnings

Vitamin A is considered safe when consumed in recommended dietary allowances (RDAs). Adults who eat fortified foods with vitamin A, such as low-fat dairy products and a lot of fruits and vegetables, generally do not require supplements or multivitamins that contain vitamin A.

Adverse effects from vitamin A may include mouth ulcers, cracked lips, psoriasis flare-ups, cracked fingernails, sore eyes, scaling skin, hair loss, skin irritation, skin dryness, pain, and redness (topical analogs), as well as diarrhea, dyspepsia, steatosis (fatty change), perisinusoidal fibrosis (in the liver), chronic hepatitis, cirrhosis, transient fullness and bulging of the anterior fontanelle, cough, fever, respiratory infection, and increased risk of lung cancer, HIV transmission (through breastfeeding), and mortality.

Vitamin A toxicity, or hypervitaminosis A, is rare in the general population. Vitamin A toxicity can occur with excessive amounts of vitamin A taken over short or long periods of time. Consequently, toxicity can be acute or chronic. Symptoms of acute (short-term) toxicity include nausea, headache, fatigue, loss of appetite, dizziness, dry skin, desquamation (loss of skin), and cerebral edema (swelling in the brain). Symptoms of chronic (longer-term) toxicity include dry itchy and cracking skin, desquamation, dry lips, scaling anorexia, headache, psychiatric changes, cerebral edema, bone and joint pain, osteoporosis, and hip fracture. Severe toxicity can lead to eye damage, high levels of calcium, and liver damage. In children, signs of toxicity include irritability, drowsiness, dizziness, delirium, coma, vomiting, diarrhea, increased intracranial pressure with bulging fontanelles in infants, headache, swelling of the optic (eye) disk, bulging eyeballs, visual disturbances, and skin redness and peeling.

Persons with liver disease and high alcohol intake may be at risk for hepatotoxicity from vitamin A supplementation. Vitamin A toxicity may lead to intrahepatic cholestasis, a condition where bile cannot flow from the liver into the intestines. Treatment with ursodeoxycholic acid has been shown to greatly improve the symptoms of cholestasis.

Use cautiously in children and infants, as high-dose vitamin A has been shown to increase the risk of respiratory infection in preschool-aged children and infants less than one month of age.

Use cautiously in combination with bile acid sequestrants, oral contraceptives, mineral oil, neomycin, or orlistat, due to reduced absorption of vitamin A.

Use cautiously in combination with alcohol or anticancer agents, due to the potential for increased risk of adverse effects.

Vitamin A may increase the risk of bleeding. Avoid in patients with bleeding disorders or those taking drugs that may increase the risk of bleeding.

Avoid in combination with tetracycline antibiotics, hepatotoxic agents, or retinoids, due to the increased risk of toxic effects.

Avoid in patients with fat malabsorption syndromes, intestinal infections, severe protein energy malnutrition, liver disease, or type V hyperlipoproteinemia (a genetic disorder).

Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or cardiovascular disease. High-dose vitamin A and beta-carotene should be avoided in patients at high risk of lung cancer.

Avoid in individuals with a known hypersensitivity or allergy to vitamin A or any component of the formulation.

Pregnancy and Breastfeeding

Vitamin A should only be used within the recommended dietary allowance, because vitamin A excess, as well as deficiency, has been associated with birth defects. Excessive doses of vitamin A have been associated with central nervous system malformations.

Vitamin A is excreted in human breast milk. The benefits or dangers to nursing infants have not been clearly established.

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