VITAMIN B12, SERUM

Vitamin B12, Serum

What it is

The Vitamin B12, Serum test measures the amount of vitamin B12 in your blood. Vitamin B12, also known as cobalamin, is an essential nutrient that helps produce red blood cells, supports nerve function, and assists in DNA synthesis. This test is commonly ordered to evaluate nutritional status and investigate possible deficiencies or related health conditions.

Uses

This test is used to detect vitamin B12 deficiency or excess, monitor patients with conditions affecting absorption (such as pernicious anemia or gastrointestinal disorders), evaluate unexplained anemia or neuropathy, and guide dietary or supplementation adjustments. It may also be part of a broader health screening or nutritional assessment.

Symptoms That May Lead to the Test

Doctors may recommend this test if you experience symptoms like fatigue, weakness, pale or jaundiced skin, numbness or tingling in hands and feet, difficulty walking, memory problems, mood changes, or unexplained weight loss. It may also be ordered in individuals with risk factors such as vegan diets, gastric surgery, or long-term use of certain medications (e.g., metformin, proton pump inhibitors).

Abnormal Results

Low Vitamin B12: May indicate deficiency due to poor diet, malabsorption disorders (like celiac disease or Crohn’s disease), pernicious anemia, or chronic medication use. Untreated deficiency can lead to anemia, nerve damage, and cognitive issues.

High Vitamin B12: Less common, but may occur with liver disease, kidney problems, diabetes, or certain blood disorders. Elevated levels can also be seen with supplementation.

Risks

The test requires a standard blood draw, which carries minimal risks such as slight pain, bruising, or dizziness. Serious complications are extremely rare.