Vitamin A Lab Test | Blood Test for Vitamin A (Retinol)

Vitamin A Test

Vitamin A (retinol) plays a key role in many body functions and is important for your heart, lungs, bones, and skin. It is also needed for healthy eyesight, metabolism, and a strong immune system. Too little retinol may increase your risk for developing infections, weakened bones, vision problems, anemia, tiredness, or dry skin and hair, but excess vitamin A can also cause problems over time. Because your body can’t make vitamin A, it must come from your diet. However, since it’s a fat-soluble nutrient, levels are generally recommended to be monitored before and during supplement use to avoid excess. Measuring your vitamin A level can help you and your healthcare provider determine whether changes to your diet or supplements may be beneficial. Read more

Test details

Sample type:

Blood

Preparation:

Fasting (not eating or drinking anything except water) for 8-12 hours is recommended. Certain supplements and medications can interfere with your test results. If you are concerned about any of your supplements or medications impacting your results, talk to your healthcare provider before your sample is collected to see if you should stop taking them and for how long.

Test type: In Person

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$49.00

+ $6.00 Physician Service Fee

Quantity

About the test

This blood test measures the amount of vitamin A (retinol) in your bloodstream. Retinol is the primary form of vitamin A circulating in the blood. Measuring your retinol level can help assess whether you have too little or too much vitamin A.

Vitamin A is a fat-soluble nutrient that plays an essential role in many core body functions. It supports normal vision—especially in low-light conditions—helps maintain a healthy immune system, and is important for the health of skin, tissues, and mucous membranes. Because your body cannot produce vitamin A on its own, it must be obtained through diet or supplements, however, as a fat-soluble nutrient, it is generally recommended to monitor levels before and during supplement use to prevent excess.

Low vitamin A levels may be linked with vision changes (particularly difficulty seeing in low light), increased susceptibility to infections, and changes in skin or tissue health. Low levels are also associated with issues of fat malabsorption, such as in celiac disease and inflammatory bowel disease. In contrast, excessively high vitamin A levels—most often related to taking too many supplements—can also be harmful and may cause headaches, blurred vision, nausea, or dizziness. Testing can help provide clarity about your current vitamin A status so you and your healthcare provider can make informed decisions about diet, supplements, or if additional testing may be useful.

No doctor’s visit needed. Buy this blood test for vitamin A and visit a nearby Quest location.

This test may be right for you if any of the following are true:

You are curious about your current vitamin A level
You have a health condition related to a vitamin A deficiency (eg, vision issues such as night blindness or skin issues such as dry and scaly skin, particularly around the eyes)
You have a health condition that affects your body’s ability to absorb vitamin A (eg, celiac disease or inflammatory bowel disease)
You take a medication long-term that may affect your body’s ability to absorb vitamin A (eg, fat-blocking weight-loss drugs, or frequent laxative use)
You are taking vitamin A supplements and want to monitor your level
You follow a low-fat diet or a diet low in vitamin A (eg, one low in egg or dairy)
You drink alcohol excessively, smoke, or use tobacco products, have had bariatric surgery or other rapid weight loss events which can affect the absorption of vitamin A
You are exhibiting signs and symptoms of a vitamin A deficiency or excess (see Signs & symptoms section below)

Please speak to your healthcare provider if you exhibit conditions listed in the Signs & symptoms section below.

Vitamin A, also called retinol, is a fat-soluble vitamin needed for healthy eyesight, cell growth, reproduction, metabolism, and a strong immune system. Getting enough retinol is important for your heart, lungs, bones, and skin. Too little retinol may increase your risk for developing infections, weakened bones, vision problems, anemia, tiredness, or dry skin and hair.

Signs and symptoms of vitamin A deficiencies include the following:

Vision issues including difficulty seeing in low light or at night
Dryness of eyes
Changes to skin and tissue, particularly becoming more dry and scaly
Increased susceptibility to infections, particularly more frequent or more severe respiratory or gastrointestinal infections
Poor wound healing

Vitamin A deficiency may occur due to inadequate dietary intake as well as conditions that affect fat absorption.

Excessively high levels of vitamin A—most often related to taking too many supplements—may be associated with:

Headaches
Blurred vision
Nausea or dizziness
Dry or peeling skin
Hair loss
Fatigue
Aching joints and bones
Changes in liver function

Symptoms of vitamin A imbalance are not specific and can overlap with other conditions. Lab testing can help determine whether vitamin A levels are low, within range, or elevated, and whether follow-up with a healthcare provider is appropriate.

Purchaser: You must be 18 years of age or older to purchase a test on questhealth.com.

Patient: This test can be performed on patients between 18 and 100 years old.

Sample collection: This test requires sample collection at a Quest Diagnostics location or through Quest Mobile^TMwhere available, a convenient option for in-home sample collection*. Collection not available in AK, AZ, or HI.

*Check your zip code here for service availability, testing may not be available in all locations. Quest Mobile is currently only available for individuals ages 18+.

After you provide your specimen, it generally takes up to 8 business days to process and release your test results. However, processing times may vary. Your test results will be available in a clear and easy-to-read report. If you have or create a MyQuest^® account, you may be able to review your new results there with your other Quest results. Independent healthcare providers are available to discuss questions or concerns you may have regarding your results.

How it works

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Complete your test sample collection during your scheduled appointment.

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Access results online as soon as they’re available. You will be emailed when they are ready. Discuss your results with an independent healthcare provider at no extra cost. Treatment options may be available.

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No doctor visit required for purchase. If in-home service is available in your area, purchase for an additional $79 fee.

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After you make a purchase, register your test and Quest Mobile will contact you to schedule an in-home sample collection appointment.

In-home sample collection

A Quest Mobile phlebotomist will collect your sample and deliver it to Quest Diagnostics.

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Please note: Quest Mobile is currently only available for individuals ages 18+.

Learn more about vitamin A and other critical vitamins and minerals in this article.

FAQs

Would taking supplements be helpful if I am deficient in vitamin A?

If your body is not absorbing certain nutrients properly or your diet won’t support appropriate levels, your doctor may suggest you consider taking a supplement for that nutrient.

Some people with low vitamin A levels may benefit from dietary changes or supplementation, depending on the cause. However, because vitamin A is fat-soluble and stored in the body, healthcare providers will generally recommend that taking of supplements is guided by regular test results and medical follow-up.

What’s the difference between water-soluble and fat-soluble vitamins?

Water-soluble and fat-soluble vitamins differ in how they are absorbed by the human body. A water-soluble vitamin dissolves in water and is easily absorbed by the body. Your body does not store these vitamins for long, so any extra will be eliminated in your urine. Because of this, it's important to consume them every day.

A fat-soluble vitamin dissolves in fats and oils and is absorbed with the fats you eat. Your body stores any extra in your liver or fatty tissues. Because of this, you don't need to consume them every day.

Can you get too much vitamin A?

Yes. Excessive vitamin A intake—most commonly from supplements—can be harmful over time. High vitamin A levels may affect the liver, bones, skin, and other body systems. This is why testing is helpful before starting or increasing vitamin A supplementation.

Is vitamin A from food different from supplements?

Yes. Vitamin A from food comes in two forms:

Preformed vitamin A (retinol) from animal-based foods
Provitamin A carotenoids (such as beta-carotene) from fruits and vegetables

Vitamin A from food is generally well regulated by the body, while supplements—particularly those containing retinol—can increase the risk of excessive vitamin A if not monitored.

Why might vitamin A levels be low even if I eat a balanced diet?

Vitamin A requires dietary fat and normal digestive function to be absorbed. Low levels may occur in people with conditions that affect fat absorption, such as certain gastrointestinal disorders, or in those following very low-fat diets. In these cases, diet alone may not fully explain low vitamin A levels.

Why test vitamin A before supplementing?

Symptoms of vitamin A imbalance are often nonspecific and can overlap with other conditions (see Signs and symptoms section above). Testing can help determine whether vitamin A levels are low, within range, or elevated, and whether dietary changes, supplements, or follow-up with a healthcare provider may be appropriate. Additionally, because vitamin A is fat-soluble and stored in the body, healthcare providers will generally recommend that supplementation is guided by regular test results and medical follow-up.

Can I use my FSA or HSA funds to purchase tests on questhealth.com?

You may be able to use your FSA or HSA funds to purchase lab tests at questhealth.com. Please review your FSA/HSA plan or check with a tax professional to confirm specific requirements for individual eligibility.

Our references

1. Merck Manual Consumer Version. Vitamin A Excess. Accessed December 12, 2025. https://www.merckmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-a-excess

2. Merck Manual Consumer Version. Vitamin A Deficiency. Accessed December 12, 2025. https://www.merckmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-a-deficiency

3. National Institutes of Health Office of Dietary Supplements. Vitamin A Fact Sheet for Professionals. Accessed December 12, 2025. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/

4. Mayo Clinic. Vitamin A. Accessed December 12, 2025. https://www.mayoclinic.org/drugs-supplements-vitamin-a/art-20365945

5. Cleveland Clinic. Vitamin A Toxicity. Accessed December 12, 2025. https://health.clevelandclinic.org/vitamin-a-toxicity

Tests purchased on questhealth.com are only for individuals who intend to pay directly for testing and do not want to submit a claim for reimbursement under their health insurance.

Vitamin A Test