Vitamin A Toxicity

Vitamin A toxicity may also be called Hypervitaminosis A. It is a disorder in which there is too much vitamin A in the body.

Causes

Vitamin A is a fat-soluble vitamin that is stored in the liver. Many foods contain vitamin A, including:

• Meat, fish, and poultry
• Dairy products
• Some fruits and vegetables

Some dietary supplements also contain vitamin A.

Supplements are the most common cause of vitamin A toxicity. It tends not to occur just from eating vitamin A-rich foods.

Too much vitamin A can make you sick. Taking large doses during pregnancy can cause birth defects.

• Acute vitamin A poisoning occurs quickly. It can happen when an adult takes several hundred thousand international units (IUs) of vitamin A.
• Chronic vitamin A poisoning may occur over time in adults who regularly take more than 25,000 IU a day.
• Babies and children are more sensitive to vitamin A. They can become sick after taking smaller doses of it. Swallowing products that contain vitamin A, such as skin cream with retinol in it, can also cause vitamin A poisoning.

Symptoms

Symptoms may include:

• Abnormal softening of the skull bone (in infants and children)
• Blurred vision
• Bone pain or swelling
• Bulging of the soft spot in an infant's skull (fontanelle)
• Changes in alertness or consciousness
• Decreased appetite
• Dizziness
• Double vision (in young children)
• Drowsiness
• Hair changes, such as hair loss and oily hair
• Headache
• Irritability
• Liver damage
• Nausea
• Poor weight gain (in infants and children)
• Skin changes, such as cracking at corners of the mouth, higher sensitivity to sunlight, oily skin, peeling, itching, and yellow color to the skin
• Vision changes
• Vomiting

Diagnosis of Vitamin A Toxicity

These tests may be done if a high vitamin A level is suspected:

• Bone x-rays
• Blood calcium test
• Cholesterol test
• Liver function test
• Blood test to check vitamin A level
• Blood test to check other vitamin levels.

Treatment

Treatment involves simply stopping supplements (or in rare cases, foods) that contain vitamin A.

Most people fully recover. Complications can include:

• Very high calcium levels
• Failure to thrive (in infants)
• Kidney damage due to high calcium
• Liver damage.

Taking too much vitamin A during pregnancy may cause birth defects. Talk to your health care provider about eating a proper diet while you are pregnant.