Hypervitaminosis A

Hypervitaminosis A results from excessive vitamin A accumulation, primarily due to high-dose supplements or fortified foods. Symptoms range from mild (fatigue, dry skin) to severe (liver damage, coma).

Hypervitaminosis A, also known as vitamin A toxicity, occurs when excessive amounts of vitamin A accumulate in the body. This usually happens due to chronic, high-dose oral intake of vitamin A supplements, fortified foods, or certain medications containing retinoids. Acute toxicity can occur from a single extremely high dose, but is less common. Symptoms can range from mild and non-specific (e.g., fatigue, irritability, dry skin) to severe, including nausea, vomiting, headache, blurred vision, bone and joint pain, hair loss, skin peeling, liver damage (hepatomegaly, cirrhosis), increased intracranial pressure (pseudotumor cerebri), and in extreme cases, coma. Chronic toxicity is more common and can lead to these more severe complications over time. Infants and children are more susceptible to vitamin A toxicity than adults. Symptoms in children can include poor weight gain, skeletal abnormalities, and bulging fontanelles. Preformed vitamin A (retinol) is more likely to cause toxicity than provitamin A carotenoids (e.g., beta-carotene) because the body converts carotenoids to retinol as needed, preventing excessive accumulation.