Serum Vitamin B12
- Sample Type
- Serum
- Fasting
- Required
- Unit
- pg/mL
Function
Vitamin B12 (Cobalamin) is an essential nutrient required for proper red blood cell formation, neurological function, and DNA synthesis. Since the body cannot produce B12, it must be obtained from animal-based foods or fortified supplements. It is bound to intrinsic factor in the stomach and absorbed in the small intestine.
Why it is Ordered
This test is used to investigate several symptoms and conditions:
- Anemia: Specifically Megaloblastic/Macrocytic anemia, where red blood cells are abnormally large.
- Neuropathy: Numbness, tingling, or weakness in the hands and feet.
- Cognitive Issues: Memory loss or confusion.
- Malabsorption screening: For patients with Crohn's or Celiac disease.
Associated Conditions
- Pernicious Anemia: An autoimmune condition where the body lacks intrinsic factor.
- Vitamin B12 Deficiency: Common in strict vegans or those with reduced stomach acid (common in the elderly).
- Hypervitaminosis B12: High levels, often from over-supplementation or underlying liver/kidney issues.
Check Your Result
Check Your Result
Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
Serum B12 levels can be deceptive. A patient can have 'normal' serum B12 but still have a functional cellular deficiency. Checking Methylmalonic Acid (MMA) or Homocysteine levels provides a clearer picture of actual deficiency. Furthermore, high doses of Vitamin C can interfere with B12 assays if taken shortly before the blood draw, and liver disease can falsely elevate B12 levels.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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