Vitamin A (Retinol) levels: what's normal, high and low
A fat-soluble vitamin essential for vision, immune function, and skin health.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Vitamin A (Retinol) is measured with a standard blood draw after an 8–12 hour fast. A typical reference range is 38.0 – 98.0 mcg/dL. At TestWell it's $44.99 all-in as Vitamin A (Retinol), results in 3–5 business days, drawn at Quest. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- mcg/dL / ug/dL
- Sample
- Blood draw
- Fasting
- 8–12 hours
- Results
- 3–5 business days
- Price
- $44.99
- Labs
- Quest
Vitamin A (Retinol) Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 38.0 – 98.0 mcg/dL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
Have a result in hand? analyze it with your AI assistant using these reviewed ranges, or run it through our explainer. Tools: look up another marker's range · convert lab units
What your Vitamin A (Retinol) result may mean
Usually reflects supplement excess. Toxicity can cause headaches, liver damage, and birth defects.
What a high Vitamin A (Retinol) means: causes, symptoms, next steps ↓Can reflect malabsorption, liver disease, or inadequate dietary intake.
What a low Vitamin A (Retinol) means: causes, symptoms, next steps ↓Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
What does a high Vitamin A (Retinol) mean?
High vitamin A (retinol) almost always comes from supplements — high-dose vitamin A, cod-liver oil, some 'immune' or skin formulas — or from very high liver consumption; retinoid medications for acne and psoriasis do not raise serum retinol but carry the same toxicity. Chronic excess causes headaches, dry skin, hair loss, bone pain, liver injury and, in pregnancy, birth defects. Kidney disease and oral estrogens raise it modestly.
Common causes of a high Vitamin A (Retinol)
- Vitamin A supplements above ~10,000 IU/day, cod-liver oil, multivitamin stacking
- Frequent liver or liver-based foods
- Chronic kidney disease (reduced clearance)
- Oral contraceptives (raised retinol-binding protein)
- Hyperlipidemia
Ordered from most to least common.
Symptoms that can go with it
- Headache, nausea, blurred vision (acute)
- Dry cracked skin and lips, hair loss, bone and joint pain, fatigue, liver enzyme elevation (chronic)
What clinicians usually check next
- Stop supplemental vitamin A and retest in 8–12 weeks
- Liver panel, kidney function, lipids
- Pregnancy: stop immediately and inform the obstetric clinician — vitamin A excess is teratogenic
Seek care promptly if
- High vitamin A with severe headache, vomiting or vision changes — same-day care (possible raised intracranial pressure)
Does beta-carotene count?
No — beta-carotene converts to vitamin A only as needed and is not toxic in the same way, though large amounts turn skin orange. Only preformed vitamin A (retinol, retinyl esters) raises this test and carries the toxicity.
Educational only — not a diagnosis. A single result outside the range is a prompt to look closer with a clinician.
What does a low Vitamin A (Retinol) mean?
Low vitamin A is uncommon in the US and points to fat malabsorption — celiac disease, Crohn's, cystic fibrosis, chronic pancreatitis, bariatric surgery, cholestatic liver disease — or to a very restricted diet, heavy alcohol use or zinc deficiency (zinc is needed to mobilize vitamin A from the liver). Acute illness lowers the measured level temporarily because retinol-binding protein falls.
Common causes of a low Vitamin A (Retinol)
- Fat malabsorption: celiac disease, Crohn's disease, cystic fibrosis, pancreatic insufficiency, bile-acid deficiency
- Bariatric surgery, especially bypass procedures
- Very low-fat or restrictive diets, alcohol use disorder, malnutrition
- Zinc deficiency, liver disease
- Acute infection or inflammation (transient), premature infants
Ordered from most to least common.
Symptoms that can go with it
- Difficulty seeing in dim light, dry eyes
- Dry, rough skin, frequent infections, slow wound healing
What clinicians usually check next
- Repeat when well; zinc, vitamins D and E, albumin, CRP
- Celiac antibodies, stool fat or elastase if malabsorption is suspected
- Dietitian or GI review; supplementation is dosed by a clinician because of the toxicity margin
Follow-up tests at TestWell: Zinc ($26.99), C-Reactive Protein (CRP) ($26.99).
Should I just take a vitamin A supplement?
Only after the cause is known and with a clinician setting the dose — the gap between correcting a deficiency and toxicity is narrower than for most vitamins, and pregnancy changes the limits further.
Educational only — not a diagnosis. A single result outside the range is a prompt to look closer with a clinician.
How do you get a Vitamin A (Retinol) test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Vitamin A (Retinol) is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Vitamin A (Retinol) | This marker only | $44.99 |
Quest vs. Labcorp for Vitamin A (Retinol): which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $44.99 |
| Labcorp | No | — |
| BioReference (NY & NJ) | No | — |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Related Vitamins & Nutrients biomarkers
Markers commonly tested alongside Vitamin A (Retinol).
Frequently asked
What does a high Vitamin A (Retinol) mean?
High vitamin A (retinol) almost always comes from supplements — high-dose vitamin A, cod-liver oil, some 'immune' or skin formulas — or from very high liver consumption; retinoid medications for acne and psoriasis do not raise serum retinol but carry the same toxicity. Chronic excess causes headaches, dry skin, hair loss, bone pain, liver injury and, in pregnancy, birth defects. Kidney disease and oral estrogens raise it modestly.
Does beta-carotene count?
No — beta-carotene converts to vitamin A only as needed and is not toxic in the same way, though large amounts turn skin orange. Only preformed vitamin A (retinol, retinyl esters) raises this test and carries the toxicity.
What does a low Vitamin A (Retinol) mean?
Low vitamin A is uncommon in the US and points to fat malabsorption — celiac disease, Crohn's, cystic fibrosis, chronic pancreatitis, bariatric surgery, cholestatic liver disease — or to a very restricted diet, heavy alcohol use or zinc deficiency (zinc is needed to mobilize vitamin A from the liver). Acute illness lowers the measured level temporarily because retinol-binding protein falls.
Should I just take a vitamin A supplement?
Only after the cause is known and with a clinician setting the dose — the gap between correcting a deficiency and toxicity is narrower than for most vitamins, and pregnancy changes the limits further.
Do I need a doctor's order to test my vitamin a (retinol)?
No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.
How long does it take to get Vitamin A (Retinol) results?
Most Vitamin A (Retinol) results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal.
How much does a Vitamin A (Retinol) test cost?
Our Vitamin A (Retinol) starts at $44.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted.
Do I need to fast before my Vitamin A (Retinol) test?
Yes — for the most accurate result, fast for 8–12 hours before your blood draw. Water is fine; coffee, food, and supplements are not. Your prep instructions will be included with your order.
Which lab will process my Vitamin A (Retinol) test?
Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations.
What can throw off a Vitamin A (Retinol) result?
Oral contraceptives and estrogen can change a Vitamin A (Retinol) result without anything being wrong. Oral contraceptives and estrogen can raise Vitamin A — expected; ferritin often improves because periods are lighter. Each is explained on our physician-reviewed "Before your test" pages; when one applies, remove it and retest.
Ready to test your vitamin a (retinol)?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $44.99.