Folate, RBC

The Folate, RBC test contains 1 test with 1 biomarker.

Brief Description: The Folate RBC (Red Blood Cell) test is a blood test that measures the level of folate within red blood cells. Unlike serum folate tests that measure the amount of folate in the liquid part of the blood, the Folate RBC test provides a more accurate and stable assessment of long-term folate status.

Collection Method: Blood Draw

Specimen Type: Whole Blood

Test Preparation: No preparation required

When is a Folate RBC test ordered?

When a complete blood count and/or blood smear, performed as part of a health checkup or anemia evaluation, reveal a low red blood cell count with the presence of big RBCs, B12 and folate levels may be ordered. A high mean corpuscular volume, in particular, implies that the RBCs are enlarged.

When a person exhibits the following signs and symptoms of a deficit, testing for folate levels may be necessary.

• Diarrhea
• Dizziness
• Muscle weakness, fatigue
• Appetite loss.
• Skin that is pale
• Irregular heartbeats, rapid heart rate
• Breathing problems
• Tongue and mouth ache
• In the feet, hands, arms, and legs, there is tingling, numbness, and/or burning 
• Confusion or obliviousness
• Paranoia

When a person is at risk of deficiency, such as those with a history of malnutrition or a condition associated to malabsorption, folate testing may be ordered.

Individuals being treated for malnutrition or a folate deficit may have these tests done on a frequent basis to see how effective their treatments are. This could be part of a long-term therapy plan for people who have a disease that causes chronic deficiency.

What does a Folate RBC test check for?

The B complex of vitamins includes vitamins including vitamin B12 and folate. They are required for the creation of normal red blood cells, tissue and cell repair, and the synthesis of DNA, the genetic material in cells. Both are nutrients that the body cannot make and must be obtained from the diet.

Vitamin B9 tests, also known as folate tests, diagnose vitamin deficiencies by measuring vitamin levels in the liquid section of the blood. The amount of folate in red blood cells is sometimes tested as well.

Folate is a naturally occurring form of the vitamin, whereas folic acid is a supplement that can be added to foods and beverages. Leafy green vegetables, dry beans and peas, citrus fruits, yeast, and liver all contain it. Vitamin B12, also known as cobalamin, can be found in animal-based foods such red meat, fish, poultry, milk, yogurt, and eggs. Fortified cereals, breads, and other grain products have become key sources of B12 and folate in recent years

A lack of folate can cause macrocytic anemia, a condition in which red blood cells are bigger than normal. Megaloblastic anemia is a kind of macrocytic anemia marked by the generation of fewer but larger RBCs known as macrocytes, as well as cellular abnormalities in the bone marrow. Reduced white blood cell and platelet counts are two more test results linked to megaloblastic anemia.

Folate is required for cell division, which occurs in the developing fetus. In a growing fetus, a lack of folate during early pregnancy can raise the chance of neural tube abnormalities such spina bifida.

Folate deficiency is most commonly caused by inadequate intake of the vitamin through diet or supplements, poor absorption, or increased bodily requirement, as observed during pregnancy:

• Dietary deficiencies are uncommon in the United States since many meals and beverages are fortified with vitamins that the body stores. Adults normally have around three months' worth of folate stored in their liver. Dietary deficiencies normally do not manifest symptoms until the body's vitamin supplies have been exhausted.
• Increased demand—this can occur as a result of a range of diseases and disorders. When a woman is pregnant or nursing, in early childhood, with malignancies, or with chronic hemolytic anemias, there is an increased demand for folate.

Lab tests often ordered with a Folate RBC test:

When a Folate RBC test is ordered, it's often part of a broader evaluation of anemia and nutritional status. Here are some tests commonly ordered alongside it:

1. Serum Folate:

   • Purpose: To measure the level of folate in the serum.
   • Why Is It Ordered: To assess the current folate status in the body. Comparing serum folate with RBC folate levels can give a more comprehensive picture of folate status over time.

2. Complete Blood Count (CBC) with Differential:

   • Purpose: To evaluate overall blood health, including red and white blood cells, and platelets.
   • Why Is It Ordered: To check for signs of anemia, particularly megaloblastic anemia, which is often caused by folate deficiency.

3. Vitamin B12 Level:

   • Purpose: To measure the level of vitamin B12 in the blood.
   • Why Is It Ordered: Vitamin B12 deficiency can cause megaloblastic anemia similar to that caused by folate deficiency. It's important to differentiate between these two causes.

4. Homocysteine and Methylmalonic Acid (MMA):

   • Purpose: To test for markers that can be elevated in B12 deficiency.
   • Why Is It Ordered: Elevated homocysteine and MMA levels can indicate B12 deficiency, even when B12 levels are borderline normal.

5. Liver Function Test:

   • Purpose: To assess liver health.
   • Why Is It Ordered: Liver disease can affect folate storage and metabolism.

6. Kidney Function Test:

   • Purpose: To evaluate kidney function.
   • Why Is It Ordered: Kidney disease can affect folate levels and the body's ability to retain and use folate.

7. Iron Studies:

   • Purpose: To evaluate iron status.
   • Why Is It Ordered: To assess for iron deficiency anemia, which can coexist with folate deficiency.

8. Reticulocyte Count:

   • Purpose: To measure the number of young red blood cells in the blood.
   • Why Is It Ordered: To assess the bone marrow's response to anemia and its ability to produce new red blood cells.

These tests, when ordered alongside a Folate RBC test, provide a comprehensive assessment of the patient's hematological health and nutritional status. They are crucial for diagnosing and managing conditions such as anemia and for ensuring appropriate folate levels for optimal body function. The specific combination of tests will depend on the individual’s symptoms, dietary intake, medical history, and the results of initial screenings

Conditions where a Folate RBC test is recommended:

• Folate Deficiency: Low levels of folate can lead to anemia, fatigue, weakness, and even cognitive disturbances. This test helps diagnose and monitor folate deficiency.

• Macrocytic Anemia: This type of anemia is characterized by abnormally large red blood cells. Folate deficiency can be a cause, and this test can aid in identifying the underlying issue.

How does my health care provider use a Folate RBC test?

Separate tests for vitamin B12 and folate are frequently used in conjunction to detect deficiencies and to aid in the diagnosis of anemias such as pernicious anemia, an inflammatory condition that inhibits B12 absorption.

B12 and folate are two vitamins that the body cannot generate and must be obtained from the diet. They're needed for red blood cell creation, tissue and cell repair, and DNA synthesis, which is the genetic material in cells. B12 is required for normal nerve function.

B12 and folate tests can also be used to assess someone who is experiencing mental or behavioral changes, especially in the elderly. A B12 test can be ordered with or without folate, as well as with other screening laboratory tests like a complete blood count, comprehensive metabolic panel, antinuclear antibody, C-reactive protein, and rheumatoid factor, to help determine why a person is exhibiting signs and symptoms of a nerve disorder.

B12 and folate tests can also be performed in conjunction with a variety of other tests to assess a person's overall health and nutritional status if they have signs and symptoms of substantial malnutrition or dietary malabsorption. People with alcoholism, liver disease, stomach cancer, or malabsorption diseases including celiac disease, inflammatory bowel disease, or cystic fibrosis may fall into this category.

Testing may be performed to assess the success of treatment in patients with known B12 and folate deficits. This is especially true for people who cannot absorb B12 and/or folate effectively and must be treated for the rest of their lives.

Folate levels in the blood's liquid part might fluctuate depending on a person's recent diet. Because red blood cells contain 95 percent of circulating folate, a test to evaluate folate levels inside RBCs could be employed instead of or in addition to the serum test. Some doctors believe that the RBC folate test is a better predictor of long-term folate status and is more clinically useful than serum folate, however there is no consensus on this.

Homocysteine and methylmalonic acid are two more laboratory tests that can be used to detect B12 and folate deficits. In B12 deficiency, both homocysteine and MMA are high, whereas in folate deficit, only homocysteine, not MMA, is elevated. This distinction is critical because treating anemia with folate treats the anemia but not the brain damage, which may be irreparable.

What do my Folate Serum test results mean?

Normal folate levels may indicate that a person does not suffer from a deficiency and that the signs and symptoms are caused by something else. Normal levels, on the other hand, may indicate that a person's stored folate has not yet been depleted.

A low folate level in a person with signs and symptoms implies a deficiency, although it does not always indicate the severity of the anemia or related neuropathy. Additional tests are frequently performed to determine the source of the deficit. Low folate levels can be caused by a variety of factors.

Dietary folate deficiency is uncommon in the United States. It can be evident in people who are malnourished in general and vegans who do not eat any animal products. Folate deficiency has become extremely rare since the development of fortified cereals, breads, and other grain products.

Folate deficits can be caused by diseases that prevent them from being absorbed in the small intestine. These may include the following:

• Pernicious anemia.
• Celiac disease
• Crohn's disease and ulcerative colitis
• Bacterial overgrowth or the presence of parasites in the intestines, such as tapeworms
• Long-term usage of antacids or H2 proton pump inhibitors reduces stomach acid production.
• Absorption can be considerably reduced by surgery that removes part of the stomach or the intestines, such as gastric bypass.
• Insufficiency of the pancreas
• Chronic alcoholism or heavy drinking
• Some treatments, such as metformin, omeprazole, methotrexate, or anti-seizure medications like phenytoin.
• Increased requirement for healthy fetal development, all pregnant women require an increased amount of folate and are advised to consume 400 micrograms of folic acid every day. People who have cancer that has spread or who have chronic hemolytic anemia require more folate.
• Smoking

If a person is taking supplements to treat a folate deficiency, normal or higher findings indicate that the treatment is working.

Most Common Questions About the Folate RBC test:

Clinical Indications and Applications

What are the main indications for conducting a Folate RBC test?

The Folate RBC test is typically used to assess folate status in the body. It can help in diagnosing megaloblastic anemia and other conditions that may be associated with folate deficiency or malabsorption. Clinicians might request the test when symptoms like fatigue, weakness, or difficulty concentrating are present, especially when coupled with a diet that may be deficient in folate.

How does the Folate RBC test differ from serum folate testing?

The Folate RBC test measures the amount of folate within the red blood cells, reflecting the body's folate status over a longer period (approximately 120 days). Serum folate testing, on the other hand, reflects more immediate or short-term folate status, assessing the level of folate in the blood plasma. While the serum test might show temporary fluctuations, the RBC test provides a more consistent and chronic view of folate status.

Diagnosis and Treatment Management

How is the Folate RBC test used in the diagnosis of megaloblastic anemia?

Megaloblastic anemia is often caused by deficiencies in either vitamin B12 or folate. The Folate RBC test is used to determine if a folate deficiency is contributing to the condition. Low levels of folate in the red blood cells may confirm a diagnosis of folate deficiency anemia, aiding in the differentiation from vitamin B12 deficiency.

What role does the Folate RBC test play in the management of chronic diseases like liver disease?

Chronic diseases such as liver disease can affect folate metabolism. The Folate RBC test might be used to monitor folate status in patients with liver disease, as they might be at increased risk for deficiencies. Proper management of folate levels can help in the overall treatment plan and might reduce some symptoms or complications associated with the chronic condition.

Interpretation of Results

What do elevated results in the Folate RBC test typically indicate?

Elevated results in the Folate RBC test may indicate an excess of folate in the body. While rare, this might be related to excessive dietary intake or supplementation. Some medications or treatment for other medical conditions, such as certain types of cancer, might also cause elevated folate levels.

Relationship with Other Nutrients and Medications

How does the Folate RBC test relate to vitamin B12 levels in the body?

Both folate and vitamin B12 are involved in the synthesis of DNA and red blood cells. Deficiency in either can lead to megaloblastic anemia. The Folate RBC test, along with vitamin B12 testing, can help differentiate between the deficiencies and guide the appropriate treatment.

Can certain medications affect the results of the Folate RBC test?

Yes, certain medications such as anticonvulsants, methotrexate, and some antacids with sulfasalazine can interfere with folate metabolism and absorption. This interference might impact the results of the Folate RBC test, making it essential for clinicians to be aware of any medications the patient is taking.

Guidelines and Recommendations

What are the recommended reference ranges for the Folate RBC test?

The clinical referrence range for Folate RBC is 280 ng/mL RBC and greater.

When should the Folate RBC test be preferred over serum folate testing?

The Folate RBC test is often preferred when a more chronic or long-term assessment of folate status is required. It may be particularly valuable in situations where recent dietary intake may skew serum levels, or in the management of chronic conditions where long-term monitoring is necessary.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.