Vitamin A blood test
Retinol test
The vitamin A test measures the level of vitamin A in the blood.
How the Test is Performed
Blood sample is needed
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
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
Night blindness
Night blindness is poor vision at night or in dim light.
- 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
Cystic fibrosis
Cystic fibrosis is a disease that causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body. It is one of th...
-
Pancreas problems, such as swelling and inflammation (
pancreatitis
) or the organ not producing enough enzymes (pancreatic insufficiency)
Pancreatitis
Acute pancreatitis is sudden swelling and inflammation of the pancreas.
-
Small intestine disorder called
celiac disease
Celiac disease
Celiac disease is a condition caused by damage to the lining of the small intestine. This damage comes from a reaction to eating gluten. This is a ...
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.
-
Blood test - illustration
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.
Blood test
illustration
-
Blood test - illustration
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.
Blood test
illustration
-
Vitamin D
(Alt. Medicine)
-
High blood pressure
(Alt. Medicine)
-
Atherosclerosis
(Alt. Medicine)
-
Vitamin A (Retinol)
(Alt. Medicine)
-
Stroke
(Alt. Medicine)
-
Diabetes
(Alt. Medicine)
-
Myocardial infarction
(Alt. Medicine)
-
Diabetes - type 1
(In-Depth)
-
Diabetes - type 2
(In-Depth)
-
Stroke
(In-Depth)
Review Date: 11/1/2015
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.