How to Read Vitamin B12 Test Report

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Vitamin B12 Test:

Vitamin B12 is an essential nutrient involved in erythropoiesis and in maintaining a healthy nervous system. Deficiency of this vitamin might cause several health problems and hence checking the levels of this vitamin is important. This test is a simple blood test that measures the amount of Vitamin B12 in blood.

Factors involved to understand the normal range of Vitamin B12 levels:

  1. What is the normal range of Vitamin B12 test?
  2. What does high level of Vitamin B12 mean?
  3. Causes of high Vitamin B12
  4. What does low level of Vitamin B12 mean?
  5. Symptoms of Vitamin B12 deficiency
  6. Causes of low levels of Vitamin B12
  7. Precautions to be taken to maintain normal levels of Vitamin B12
  8. Are there any risks associated with Vitamin B12 test?
  9. What other tests are ordered along with Vitamin B12 test?

What is the normal range of Vitamin B12 test?

Normal range for vitamin B12 is 200-900 ng/mL. Normal range and unit of measurement may vary between different laboratories.

What does high level of Vitamin B12 mean?

Vitamin B12 levels higher than 900 ng/mL indicates abnormally high levels of Vitamin B12. This could indicate liver or kidney problems, diabetes, or certain forms of leukemia. It could also indicate body’s failure to utilize vitamin B12. However, high levels can also be observed when a person undergoes test soon after taking B12 supplements.

Causes of high Vitamin B12

High levels of vitamin B12 occur very rarely, as excess B12 is often removed through urine. Conditions that can increase B12 levels may include:

  • Liver diseases such as cirrhosis or hepatitis
  • Myeloproliferative disorders such as polycythemia vera and chronic myelogenous leukemia

Other conditions where B12 may be higher than normal include:

  • Recent B12 injection or B12 supplement
  • Kidney disease
  • Inflammatory conditions such as rheumatoid arthritis, lupus
  • Hematologic cancers and hematopoietic disorders
  • Increased levels of transcobalamin
  • Obesity
  • Infection such as AIDS
Intrinsic factor antibodies can interfere with vitamin B12 test and cause a false elevation in the levels of vitamin B12. Estrogen, vitamin C and vitamin A can also increase vitamin B12 levels.

What does low level of Vitamin B12 mean?

Lower than 200 ng/mL of Vitamin B12 in blood indicates vitamin B12 deficiency. It can also indicate body’s failure to absorb the vitamin and inability to meet the vitamin B12 needs.

Symptoms of Vitamin B12 deficiency

Vitamin B12 deficiency can result in a person becoming anemic. Mild deficiency does not cause any symptoms. But, when untreated for a longer time, it could cause symptoms such as:

  • Weakness, fatigue, and lightheadedness
  • Heart palpitations
  • Shortness of breath
  • Pale skin
  • Gastrointestinal issues such as constipation, diarrhea, loss of appetite, or gas
  • Nerve problems such as numbness or tingling, muscle weakness
  • Vision problems
  • Depression, memory loss, behavioral changes
  • Menstrual problems

Vitamin B12 deficiency can also increase a person’s susceptibility to infections. Prolonged vitamin B12 deficiency increases the risk of permanent nerve and brain damage.

Causes of low levels of Vitamin B12

Vegetarian diet is the major reason for vitamin B12 deficiency as plant-sourced foods do not contain enough cobalamin to meet the body’s requirement. Certain health conditions can also affect the levels of vitamin B12 in blood. Vitamin B12 may be decreased in cases such as:

  • Pernicious anemia
  • A recent small intestine surgery
  • Gastritis, celiac disease, and inflammatory bowel disease (IBD)
  • Chronic alcoholism
  • Use of metformin tablets to treat diabetes
  • Autoimmune disorders such as Graves’ disease or lupus
  • Certain medications like heartburn medicines and H2 blockers

Precautions to be taken to maintain normal levels of Vitamin B12

Vitamin B12 deficiency can be prevented by introducing enough meat, poultry, seafood, dairy products, and eggs into the diet. Vegetarians can add foods fortified with vitamin B12 to their diet. Taking vitamin V12 in a multivitamin or direct vitamin B12 supplement can also help maintain the levels and prevent deficiency.

It is often advised for individuals with low vitamin B12 levels to take regular doses of the vitamin via injections. This is also helpful for people with medical conditions that hinder the absorption of the vitamin. High levels of vitamin B12 are generally caused due to underlying disease or condition. In cases of elevated vitamin B12, underlying condition is treated to maintain the levels.

Are there any risks associated with Vitamin B12 test?

Vitamin B12 test is a simple blood test and has no major risks associated with it. Minor side effects such as bruising and bleeding, pain and soreness, hematoma, fainting or feeling lightheaded, etc. These side effects do not require medical attention.

Are there any risks associated with Vitamin B12 test?

Other screening tests such as complete blood count (CBC), comprehensive metabolic panel (CMP), antinuclear antibody test (ANA.), C-reactive protein test (CRP), and rheumatoid factor (RF) test, are ordered along with vitamin B12 test. Folate estimation is also ordered along with vitamin B12 estimation. Additional laboratory test such as intrinsic factor antibody and parietal cell antibody tests are ordered to help diagnose pernicious anemia.

Before undergoing this test, you may need to fast for several hours. Certain medications can affect the results of this test and hence, it is important to let your healthcare provider know about all the medications, herbs, and supplements you may be taking. He/she may advise you to stop taking medications.

Vitamin B12 is an essential nutrient playing a vital role in overall health. The test is often recommended to people who show signs and symptoms of a deficiency or are at a higher risk of vitamin B12 deficiency. Deficiency can be avoided by a balanced diet, oral supplements, or injections of the vitamin. Discuss with your healthcare provider before starting any supplements.


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