Vitamin B12 (Serum or Plasma Concentration)

Why This Test Matters

Vitamin B12 is essential for preventing anemia, maintaining nerve function, and supporting DNA synthesis. Low levels may indicate poor absorption, dietary deficiencies, or underlying health conditions.

What to Expect During the Test

A blood sample is drawn from a vein, usually in your arm. The test is quick and typically done in a lab setting. You may feel slight discomfort, but it usually doesn’t require special preparation.

Low vitamin B12 levels can result from dietary insufficiency, conditions like pernicious anemia, or malabsorption issues. High levels are less common but may occur with certain medications or genetic disorders.

Symptoms may include fatigue, weakness, numbness or tingling in hands/feet, balance problems, or memory issues. Some people have no symptoms until deficiency is severe.

Results are compared to a reference range provided by your healthcare provider. While ranges vary by lab, low values may trigger further testing or dietary adjustments.

If your results are low, your doctor may recommend dietary changes, vitamin supplements, or additional tests to identify the cause. High levels may require further evaluation to rule out rare conditions.