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Hypervitaminosis A
Vitamin A toxicity
Hypervitaminosis A is having too much vitamin A in the body.
Vitamin A
Vitamin A is a fat-soluble vitamin that is stored in the liver. There are two types of vitamin A that are found in the diet. Preformed vitamin A is...
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.
Too much vitamin A can make you sick. Large doses of vitamin A during pregnancy can cause birth defects.
- Acute vitamin A poisoning occurs quickly, most often 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.
Chronic
Chronic refers to something that continues over an extended period of time. A chronic condition is usually long-lasting and does not easily or quick...
ImageRead Article Now Book Mark Article - Babies and children are more sensitive to vitamin A. They can become sick after taking smaller doses of vitamin A or if they swallow products that contain vitamin A, such as skin cream with retinol in it.
Symptoms
Symptoms may include:
- Abnormal softening of the skull bone (in infants and children)
- Blurred vision
-
Bone pain
or swelling
Bone pain
Bone pain or tenderness is aching or other discomfort in one or more bones.
ImageRead Article Now Book Mark Article -
Bulging of the soft spot in an infant's skull (
fontanelle
)
Fontanelle
A bulging fontanelle is an outward curving of an infant's soft spot (fontanelle).
ImageRead Article Now Book Mark Article - Changes in alertness or consciousness
-
Decreased appetite
Decreased appetite
A decreased appetite is when your desire to eat is reduced. The medical term for a loss of appetite is anorexia.
Read Article Now Book Mark Article - Dizziness
- Double vision (in young children)
- Drowsiness
-
Hair changes, such as
hair loss
and oily hair
Hair loss
Partial or complete loss of hair is called alopecia.
ImageRead Article Now Book Mark Article - Headache
- Irritability
- Liver damage
- Nausea
-
Poor
weight gain
(in infants and children)
Weight gain
Unintentional weight gain is when you gain weight without trying to do so and you are not eating or drinking more.
ImageRead Article Now Book Mark Article - 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
Exams and Tests
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
Vitamin A
The vitamin A test measures the level of vitamin A in the blood.
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Treatment
Treatment involves simply stopping supplements (or rarely, foods) that contain vitamin A.
Outlook (Prognosis)
Most people fully recover.
Possible Complications
Complications can include:
- Excessively high calcium level
-
Failure to thrive
(in infants)
Failure to thrive
Failure to thrive refers to children whose current weight or rate of weight gain is much lower than that of other children of similar age and gender....
Read Article Now Book Mark Article - Kidney damage due to high calcium
- Liver damage
Taking too much vitamin A during pregnancy may cause abnormal development in the growing baby. Talk to your health care provider about eating a proper diet while you are pregnant.
When to Contact a Medical Professional
Call your 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
How much vitamin A you need depends on your age and gender. Other factors, such as pregnancy and your overall health, are also important. Ask your provider what amount is best for you.
Vitamin A
Vitamin A is a fat-soluble vitamin that is stored in the liver. There are two types of vitamin A that are found in the diet. Preformed vitamin A is...
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.
Beta carotene
The beta-carotene test measures the level of beta-carotene in the blood.
References
Institute of Medicine, US Panel on Micronutrients. Dietary reference intakes for vitamin A, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. National Academies Press. Washington, DC, 2001. PMID: 25057538 www.ncbi.nlm.nih.gov/pubmed/25057538 .
Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 218.
Ross AC, Tan L. Vitamin A deficiencies and excess. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 48.
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Vitamin A source - illustration
Like most vitamins, vitamin A may be obtained in the recommended amount with a well-balanced diet, including some enriched or fortified foods.
Vitamin A source
illustration
Review Date: 2/3/2016
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
