Vitamin B12 & Folate

What Is Vitamin B12?

The B-vitamins -- next to vitamin A, vitamin C, and vitamin D -- are needed for optimal function of the body and good nutritional status. Vitamin B12, also known as cobalamin, is an essential nutrient that is usually sourced in the diet from animal products. Having an adequate supply of B12 is critical for the synthesis of:

• Red blood cells
• Hemoglobin
• Protective coating on nerve cells called the myelin sheath

Vitamin B12 also works closely with a compound called methylmalonic acid (MMA) to regulate cell function.

What Is Folate?

Folate is another B vitamin, often called vitamin B9. Folate's primary roles in the body include:

• DNA formation
• RNA formation
• Protein metabolism
• Red blood cell development

What Are the Symptoms and Associated Conditions of a Vitamin B12 and Folate Deficiency?

A clinical folate and vitamin B12 deficiency can manifest in several ways.

Anemia and Vitamin B12 and Folate Deficiency

One of the most serious ways that a B12 and folate deficiency presents in is megaloblastic anemia. This condition, also known as macrocytic anemia, is characterized by the production of red blood cells that are too large to function properly.

Pernicious anemia is caused by a lack of B12 and/or folate. This condition is characterized by low levels of healthy red blood cells that are needed to transport oxygen and nutrients to cells in the body.

B12 and folate-related anemias are often triggered by a lack of intrinsic factor, a type of protein that coordinates B12 absorption in the small intestines. Deficiencies of B12 and folate are the most common causes of anemia.

The Symptoms of Vitamin B12 and Folate Deficiency

There are several telltale signs of vitamin B12 and folate deficiency such as:

• Chronic fatigue (lack of energy)
• Vision issues
• Mouth ulcers
• Paresthesia (pins and needles)
• Weakness
• Cognitive and psychological issues (anxiety, depression, mood disorders)
• Neuropathy and other neurologic symptoms
• Behavioral changes
• Nerve damage
• Pale skin

Why Measure Vitamin B12 and Folate Together?

In addition to having enough of each, vitamin B12 and folate levels in the proper ratio is also important for health. For this reason, testing both is well-advised. For example, if there is too little vitamin B12 but a normal amount of folate in the blood, the risk of anemia and cognitive impairment increases.

Who Should Order a Vitamin B12 and Folate Blood Test?

When dispensing medical advice, your healthcare provider may overlook the possibility of a deficiency or mistake the symptoms for another condition. It's up to you to determine your own levels with a simple and affordable blood test. Several chronic health conditions can negatively affect the amount of vitamin B12 and folate that is absorbed through diet (called "malabsorption"). You should order a B12 and folate test if you have:

• Liver disease
• Celiac disease
• Crohn's disease
• Received a gastric bypass

Due to the risk of birth defects resulting from low folate or vitamin B12 levels such as neural tube defects, it's especially important for pregnant women to receive this blood test, regardless of the presence of symptoms.

Some Medicines Negatively Affect Vitamin B12 and Folate Levels

Because the following medications may interfere with B12 or folate absorption, affect the metabolism of these vitamins, or otherwise deplete levels of these vitamins in the body, you should regularly monitor your B12 and folate status if you are taking the following medications:

• Methotrexate
• Proton pump inhibitors (which block stomach acid production)
• Colchicine
• Anticonvulsants
• H2 blockers
• Metformin
• Aminopterin
• Pyrimethamine

How to Safely Boost Vitamin B12 and Folate Levels

If malnutrition is the cause of a folate or vitamin B12 deficiency, here are the best ways to ensure a higher intake of vitamin B12 and folate.

Dietary Sources of Vitamin B12

Animal products are the primary dietary sources of vitamin B12. To naturally increase levels of vitamin B12, include more of the following in your diet:

• Eggs
• Dairy
• Organ meat (especially liver and kidneys)
• Fish

Dietary Sources of Folate

Green vegetables offer the highest concentrations of folate available through diet. Good dietary sources of folate include:

• Asparagus
• Avocados
• Brussels sprouts
• Spinach
• Lettuce

Dietary Supplements Containing Vitamin B12 and Folate

Depending on the severity of your deficiency, you may consider boosting your levels with supplementation. Cobalamin is the most common form of B12 supplement. Folic acid is the most common form of folate supplement. Another B-vitamin, biotin (B7), has been shown to positively affect folate levels in the body. Many "B-complex" supplements contain concentrated amounts of B12, B9, and B7. For your safety, please read the health information on any B12 or folate supplements carefully for proper dosing instructions.

How Is the Vitamin B12 and Folate Test Performed?

This blood test, also known as an assay, measures serum B12 and serum folate levels to determine the quantity of each that is in circulation. This kind of blood analysis is called hematology. The patient supplies a small blood sample which is then analyzed in a lab.

• Normal levels of B12, as determined through testing, are between 160-950 picograms per milliliter (pg/mL)
• Normal levels of folate, as determined through testing, are between 2-10 nanograms per milliliter (ng/mL)

Results outside of this range might indicate a need for further testing and corrective action.

Related Laboratory Tests to Consider

In addition to measuring B12 and folate levels, other tests can help confirm the presence of a B12 and folate deficiency and related conditions such as pernicious anemia:

• An RBC folate level test (to assess the amount of folic acid inside of red blood cells)
• Intrinsic factor (IF) antibodies test
• Homocysteine test
• Complete blood count (CBC) test

Where Can I Get a Vitamin B12 and Folate Test Near Me?

To find a convenient, nearby testing facility, please use Health Testing Center's Lab Locator. We will supply you with the correct CPT code and any necessary additional information upon request.

Sources:

"Structural basis for receptor recognition of vitamin-B12–intrinsic factor complexes." Nature. https://www.nature.com/articles/nature08874
"Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification." American Journal of Clinical Nutrition. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1828842/
"Effect of methotrexate/vitamin B12 on DNA methylation as a potential factor in leukemia treatment-related neurotoxicity." Epigenomics. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638018/
"Proton Pump Inhibitors Intake and Iron and Vitamin B12 Status: A Prospective Comparative Study with a Follow up of 12 Months." Open Access Macedonian Journal of Medical Sciences. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5874363/
"Complications: Vitamin B12 or folate deficiency anaemia." National Health Service (UK). https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/c...

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Nov 16, 2020