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Vitamin B12, Folate, and Vitamin D

Test ID: A895

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Vitamin B12 and folate are B vitamins. They play important roles in health and wellness, particularly cell metabolism and synthesis of red blood cells. The best sources of B vitamins are meat, eggs, and dairy products, as well as leafy green vegetables and legumes for many B vitamins (with the notable exception of vitamin B12, which is generally not present in plant foods).

Vitamin B deficiency is most often caused by malabsorption from food, pernicious anemia, or dietary deficiency. Deficiency is characterized by megaloblastic anemia, which causes weakness, fatigue, difficulty concentrating, irritability, headaches, heart palpitations, and shortness of breath.

Vitamin D is a fat-soluble vitamin that is naturally present in a few foods, and is produced endogenously when ultraviolet (UV) rays from sunlight trigger vitamin D synthesis. Low dietary intake, limited sun exposure, and poor vitamin D absorption can result in vitamin D deficiency. This results in rickets in children and osteomalacia in adults. Symptoms can include soft bones, skeletal deformities, failure to thrive, developmental delay, and dental abnormalities.



How to order a test

What is Included?

Measurement of blood vitamin B12, folate, and vitamin D levels by chemiluminescent microparticle Intrinsic Factor assay (B12) and chemiluminescent microparticle immunoassays (folate and D).

Turnaround Time

1 – 3 business days
The turnaround time is not guaranteed. The average turnaround time is 1 – 3 business days from the date that the sample arrives at the laboratory. Shipping time for the sample is not included. Additional time is required if the case requires confirmatory or reflex testing, or if the sample is insufficient, or if a recollection is required.

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Preparation Before Specimen Collection

Collect blood sample for this test after fasting overnight (for 8 – 12 hours). Fasting means that no food or drink (aside from water) is to be consumed.

Ensure blood sample is not exposed to bright light.

Specimen Type



50 μL in a microtainer


Microtainer (regular blood tube)

Collection Method

This test requires a blood sample from a finger prick. All supplies for sample collection are provided in the kit.

  1. First wash and dry hands. Warm hands aid in blood collection.
  2. Clean the finger prick site with the alcohol swab and allow to air dry.
  3. Use the provided lancet to puncture the skin in one quick, continuous and deliberate stroke.
  4. Wipe away the first drop of blood.
  5. Massage hand and finger to increase blood flow to the puncture site. Angle arm and hand downwards to facilitate blood collection on the fingertip.
  6. Drip blood into the microtainer tube.
  7. Dispose of all sharps safely and return sample to the laboratory in the provided prepaid return shipping envelope.

NOTES: Avoid squeezing or ‘milking’ the finger excessively. If more blood is required and blood flow stops, perform a second skin puncture on another finger. Do not touch the fingertip.

Specimen Storage

Maintain specimen at temperatures between 2°C and 30°C during storage and transport.

Specimen Stability

Blood samples can be refrigerated or kept at room temperature for up to 7 days.

Causes for Rejection

  • Incorrect or incomplete patient identification
  • Incorrect specimen collection
  • Inappropriate storage and transport conditions
  • Incorrect specimen volume



To measure vitamin B12, folate, and vitamin D levels in a blood sample for the detection of deficiency and to evaluate megaloblastic and macrocytic anemia.


  • This report is not intended for use in medico-legal applications.
  • These results should be interpreted in conjunction with other laboratory and clinical information.
  • Correct specimen collection and handling is required for optimal assay performance.
  • False results may occur in specimens from individuals that have received preparations of mouse monoclonal antibodies for diagnosis or therapy. Additional clinical or diagnostic information may be required for these specimens.
  • Assay interference may occur in specimens from individuals routinely exposed to animals or to animal serum products. Additional clinical or diagnostic information may be required for these specimens.
  • Hemolysis exhibits negative interference in this vitamin B12 assay
  • Specimens from individuals with renal impairment or failure may result in falsely depressed folate values.
  • Some chemotherapeutic agents, including methotrexate, aminopterin, and folinic acid, cross react with folate binding protein in this assay.
  • Serum specimens containing rheumatoid factor may interfere with this assay.


Chemiluminescent microparticle Intrinsic Factor assay (Alinity i B12 assay)

Chemiluminescent microparticle immunoassay (Alinity i Folate assay)

Chemiluminescent microparticle immunoassay (Alinity i 25-OH Vitamin D assay)

Reference Intervals

Vitamin B12: 200 – 835 pg/mL

Levels above 300 or 400 pg/mL are rarely associated with B12 deficiency induced hematological or neurological disease, respectively. Further testing is suggested for symptomatic patients with B12 levels between 100 and 300 pg/mL (hematological abnormalities), and between 100 and 400 pg/mL (neurological abnormalities).

This reference range was obtained from Reed R. (2020). Clinical Chemistry Learning Guide Series. Editors Armbruster D & Cooper K. Abbott.

Folate: 3.1 – 20.5 ng/mL

Folate deficiency is typically associated with serum levels less than 3.5 ng/mL.

This reference range was obtained from the Alinity i Folate package insert.

Vitamin D: 25 – 80 ng/mL

Severe deficiency: < 10 ng/mL
Mild to moderate deficiency: 10 – 24 ng/mL
Optimum levels: 25 – 80 ng/mL
Toxicity possible: > 80 ng/mL

These reference ranges were obtained from “Laboratory Reference Ranges” from the Endocrine Society.