Safety and side effects

Too much vitamin A can be harmful. Even a single large dose — over 200,000 mcg — can cause:

• Nausea
• Vomiting
• Vertigo
• Blurry vision

Taking more than 10,000 mcg a day of oral vitamin A supplements long term can cause:

• Bone thinning
• Liver damage
• Headache
• Diarrhea
• Nausea
• Skin irritation
• Pain in the joints and bone
• Birth defects

If you are or might become pregnant, talk to your doctor before taking vitamin A. Excess use of vitamin A during pregnancy has been linked to birth defects.