Hypervitaminosis A

From: http://www.nlm.nih.gov/medlineplus/ency/article/000350.htm

Hypervitaminosis A is having too much vitamin A in the body.
Causes
There are two types of vitamin A hypervitaminosis:
Acute -- caused by taking too much vitamin A over a short period of time
Chronic -- occurs when too much of the vitamin is present over a longer period
Chronic vitamin A toxicity develops after taking too much vitamin A for long periods.
Symptoms
Abnormal softening of the skull bone (craniotabes -- infants and children)
Blurred vision
Bone pain or swelling
Bulging fontanelle (infants)
Changes in consciousness
Decreased appetite
Dizziness
Double vision (young children)
Drowsiness
Fatigue
Headache
Impotence and ejaculation failure
Increased intracranial pressure
Irritability
Nausea
Osteoporosis
Poor weight gain (infants and children)
Skin and hair changes
Cracking at corners of the mouth
Hair loss
Higher sensitivity to sunlight
Oily skin and hair (seborrhea)
Skin peeling, itching
Yellow discoloration of the skin
Swelling of breast tissue in men (gynecomastia)
Vision changes
Vomiting
Exams and Tests
Bone hardening (calcification)
High blood calcium levels
High cholesterol
High serum creatinine (suggesting kidney damage)
Serum vitamin A levels
Treatment
Treatment involves simply stopping the use of too much vitamin A.
Outlook (Prognosis)
Most people fully recover.
Possible Complications
Excessively high calcium levels
Failure to thrive
Kidney damage due to high calcium
Liver damage
Osteoporosis
Prostate cancer
Recent studies show that taking too much vitamin A during pregnancy can cause abnormal development in the fetus. Talk to your health care provider about eating a proper diet while you are pregnant.
When to Contact a Medical Professional
Call your health care provider if you think that you or your child may have taken too much vitamin A, or you have symptoms of excess vitamin A.
Prevention
To avoid hypervitaminosis A, avoid taking more than the recommended daily allowance of this vitamin. Recent emphasis on vitamin A and beta carotene as anticancer vitamins may contribute to chronic hypervitaminosis A, if people take more than is recommended.
Alternative Names
Vitamin A toxicity
References
Zile M. Vitamin A deficiencies and excess. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 45.
Update Date: 6/17/2008
Updated by: Elizabeth H. Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.