Test library
B12 and Folic Acid Test
This test measures both vitamin B12 and folic acid (folate) in a single blood sample. The two nutrients work together in red blood cell production and DNA synthesis, so they are often checked as a pair.
Order Folic Acid Lab Test - B12 Deficiency Test
Order online and visit a local collection site, or choose an at-home kit where available. No referral and no insurance required.
Order Folic Acid Lab Test - B12 Deficiency Test- Typical turnaround
- 1-3 business days
- Starting price
- From $118
- Results
- Confidential, online
Quick answer
The vitamin B12 and folic acid test measures the levels of both nutrients in the blood. B12 and folate are essential for making red blood cells and for DNA synthesis. Because a shortage of either can produce similar symptoms, they are commonly ordered together. The test uses a single blood sample, and a healthcare provider interprets the results with other findings.
What this test measures
Vitamin B12 and folate are separate nutrients, but they participate in overlapping biochemical pathways. Both are needed for red blood cells to mature normally and for DNA to be produced correctly. When either is low, red blood cells can become unusually large, a pattern known as macrocytic anemia.
The panel typically measures serum vitamin B12 and serum folate, and some laboratories add red blood cell folate, which reflects longer-term status. Methylmalonic acid and homocysteine may also be included because they can rise when B12 or folate is insufficient, even when standard levels look borderline.
Testing may be requested for fatigue, unexplained anemia, tingling or numbness, or a diet low in animal products. Folate matters especially before and during pregnancy. Results guide a healthcare provider toward further evaluation, such as identifying whether absorption or intake is the underlying issue.
- Vitamin B12 (cobalamin)
- Serum folate (folic acid)
- Red blood cell folate
- Homocysteine
- Methylmalonic acid
- Complete blood count with MCV when paired
- Intrinsic factor antibodies when included
Why people order this test
- Evaluate macrocytic anemia with large red blood cells
- Investigate fatigue, tingling, or numbness
- Check B12 status on a vegan or vegetarian diet
- Assess folate before or during pregnancy
- Review nutrient status in malabsorption conditions
- Follow up after long-term use of certain medications
How to prepare
No fasting is usually required, though the laboratory may request it if other tests are bundled with the order. A blood sample is drawn from a vein, typically at the arm. Follow the collection instructions provided with the order.
Understanding your results
Results are generally available within one to three business days. The report shows B12 and folate levels with their reference ranges. A low or borderline value may prompt a healthcare provider to order additional tests and discuss next steps.
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Frequently Asked Questions
Why are B12 and folate tested together?
Both nutrients are needed for healthy red blood cells and DNA synthesis. A shortage of either can cause similar symptoms, so checking them together helps clarify the cause.
What symptoms suggest a B12 or folate problem?
Fatigue, weakness, pale skin, and tingling or numbness can occur. These symptoms have many causes and should be evaluated by a healthcare provider.
Can I take this test if I am pregnant?
Yes, and folate status is especially relevant in pregnancy. The ordering provider decides which markers are appropriate.
Does the test require fasting?
Fasting is usually not needed for B12 and folate, but it may be requested if other tests are combined with the order.
What is red blood cell folate?
It is a folate measurement inside red blood cells that reflects longer-term status rather than recent intake. Some laboratories include it for a fuller picture.
Ready to get tested?
Order online and visit a collection site near you, or choose a mail-in kit. No referral and no insurance required.
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