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 sensitivity or allergy to vitamin A or any part 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 lack the need for supplements or multivitamins that contain vitamin A.

Vitamin A may cause bleeding in the lungs, blurry vision, bone pain, breathing difficulty, changes in immune function, chronic inflammation of the liver, cirrhosis (scarring of liver), cough, cracked fingernails, cracked lips, death, decreased thyroid function, depression, diarrhea, feeling of fullness, fever, fluid around heart, hair loss, high cholesterol, increased pressure in the brain, increased risk of HIV transmission (through breastfeeding), increased risk of lung cancer, increased risk of heart disease, increased white blood cells, indigestion, inflammation of the conjunctiva (conjunctivitis), injection site pain, irritability, joint pain, mouth ulcers, muscle pain, psoriasis flare-ups, pain, perisinusoidal fibrosis (in the liver), redness (from skin use), respiratory infection, seizure, skin irritation, sore eyes, steatosis (fatty change), stomach and intestine adverse effects, and suicidal thoughts.

Vitamin A toxicity is rare in the general population. Vitamin A toxicity can occur with high amounts of vitamin A taken over short or long periods of time. Consequently, toxicity can be short or long-term. 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 (excess fluid), bone and joint pain, osteoporosis (bone loss), 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 pressure in the brain with bulging fontanelles in infants, headache, swelling of the optic (eye) disk, bulging eyeballs, visual disturbances, and skin redness and peeling.

People with liver disease and high alcohol intake may be at risk for liver toxicity from vitamin A supplementation. Vitamin A toxicity may lead to intrahepatic cholestasis, where bile cannot flow from the liver into the intestines.

Vitamin A may cause low blood pressure. Caution is advised in people with low blood pressure or in those taking drugs or herbs and supplements that lower blood pressure.

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

Use cautiously in combination with contraceptives taken by mouth, due to increased levels of vitamin A.

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

Smokers who consume alcohol and beta-carotene may be at an increased risk for lung cancer or heart disease. Use cautiously in smokers who consume alcohol.

Use cautiously in children and infants, or in people with osteoporosis, skin disorders, thyroid disorders, affective disorders, or those taking agents for depression.

Avoid taking vitamin A in high doses, due to increased risk of toxicity and death.

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

Avoid in people with poor fat absorption, intestinal infections, severe protein energy malnutrition, liver disease, or type V hyperlipoproteinemia (a genetic disorder).

High-dose vitamin A and beta-carotene should be avoided in patients at high risk of lung cancer.

Vitamin A may increase the risk of bleeding. Avoid use when taking agents that affect bleeding and clotting.

Avoid in individuals with a known sensitivity or allergy to vitamin A or any part 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 are unclear.

Tretinoin that is applied to the skin is likely low risk for breastfeeding infants given its poor absorption; however, due to a lack of evidence, caution should be taken to prevent direct skin contact to the nursing infant and only water soluble cream or gel products should be applied.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration

www.naturalstandard.com