Beta-carotene blood test

  • Definition
    • The beta-carotene test measures the level of beta-carotene in the blood.

  • Alternative Names
    • Carotene 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 8 hours before the test. You may also be asked not to eat anything with vitamin A (carotene) for 48 hours before the test.

      Your provider may also tell you to temporarily stop taking medicines, such as retinol, which may interfere with test results.

  • 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. Afterward, there may be some throbbing and slight bruising. This soon goes away.

  • Why the Test is Performed
    • Beta-carotene is found in certain foods. It breaks down to become vitamin A in the body.

      Your provider may order this test if you have signs that your vitamin A level may be too low, such as:

      • Bones or teeth that do not develop correctly
      • Dry or inflamed eyes
      • Feeling more irritable
      • Hair loss
      • Loss of appetite
      • Recurring infections
      • Skin rashes
      • Problems seeing at night

      The test can also be used to help measure how well your body absorbs fats.

  • Normal Results
    • The normal range is 50 to 300 micrograms per deciliter (mcg/dL) or 0.93 to 5.59 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 provider about the meaning of your specific test results.

  • What Abnormal Results Mean
    • A higher than normal level may be due to taking too much vitamin A (hypervitaminosis A).

      Beta-carotene deficiency may occur if you are malnourished. It can also occur if your body has trouble absorbing fats through the digestive tract such as with:

      • 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

      This test plays a valuable role in diagnosing vitamin A deficiency. But the test results must be evaluated along with other clinical findings.

  • 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. Carotene - serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:301-302.

      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.