الجــــــــــــــــــــواب:-
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DrTamer Addissouky
Vitamin A test:
Vitamin A is a fat-soluble vitamin. This article describes the test used to measure the amount of vitamin A in the blood.
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How the Test is Performed
A blood sample is needed. For information on how this is done
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How to Prepare for the Test
Do not eat or drink anything for 4 hours before the test.
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Why the Test is Performed
This test is done to determine if you have too much or too little vitamin A in your blood.
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Normal Results
Normal values range from 50 to 200 micrograms per deciliter.
The examples above are common measurements for results of these tests. 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.
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What Abnormal Results Mean
Lower than normal values mean 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
A vitamin A deficiency may occur if your body has trouble absorbing fats through the digestive tract. This may occur if you have:
Celiac disease
Cystic fibrosis
Pancreatitis
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http://www.nlm.nih.gov/medlineplus/ency/article/003570.htm