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Vitamin A blood test

  • Definition
    • The vitamin A test measures the level of vitamin A in the blood.

  • Alternative Names
    • Retinol test

  • How the Test is Performed
  • How to Prepare for the Test
    • Follow your health care provider's instructions about not eating or drinking anything for up to 24 hours before the test.

  • How the Test will Feel
    • When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterwards, there may be some throbbing or slight bruising. This soon goes away.

  • Why the Test is Performed
    • This test is done to check if you have too much or too little vitamin A in your blood. (These conditions are uncommon in the United States.)

  • Normal Results
    • Normal values range from 50 to 200 micrograms per deciliter (mcg/dL) or 1.75 to 6.98 micromoles per liter (micromol/L).

      Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

  • What Abnormal Results Mean
    • A lower than normal value means you do not have enough vitamin A in your blood. This may cause:

      • Bone or teeth problems in young children
      • Dry or inflamed eyes
      • Hair loss
      • Loss of appetite
      • Night blindness
      • Recurring infections
      • Skin rashes

      Vitamin A deficiency may occur if your body has trouble absorbing fats through the digestive tract. This may occur if you have:

      • Chronic lung disease called cystic fibrosis
      • Pancreas problems, such as swelling and inflammation (pancreatitis) or the organ not producing enough enzymes (pancreatic insufficiency)
      • Small intestine disorder called celiac disease
  • Risks
    • Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

      Other risks associated with having blood drawn are slight but may include:

      • Excessive bleeding
      • Fainting or feeling lightheaded
      • Hematoma (blood accumulating under the skin)
      • Infection (a slight risk any time the skin is broken)
  • References
    • Chernecky CC, Berger BJ. Vitamin A (retinol) - serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:1175-1177.

      Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 218.