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Hypervitaminosis A

Definition

Hypervitaminosis A is having too much vitamin A in the body.

Alternative Names

Vitamin A toxicity

Causes, incidence, and risk factors

There are two types of vitamin A hypervitaminosis:

  • Acute -- caused by taking too much vitamin A over a short period of time
  • -- occurs when too much of the vitamin is present over a longer periodChronic

Chronic vitamin A toxicity develops after taking too much vitamin A for long periods.

Symptoms

Signs and tests

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

Treatment

Treatment involves simply stopping the use of too much vitamin A.

Support Groups

Expectations (prognosis)

Most people fully recover.

Complications

  • Excessively high calcium levels
  • in infantsFailure to thrive
  • Kidney damage due to high calcium
  • Liver damage

Taking too much vitamin A during pregnancy may cause abnormal development in the developing baby. Talk to your health care provider about eating a proper diet while you are pregnant.

Calling your health care provider

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.

References

Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Schafer AI, eds. . 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 225.

Zile MH. Vitamin A deficiencies and excess. In: Kliegman RM, Stanton BF, St. Geme JW III, Schor NF, Behrman RE, eds. . 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 45.

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.