Vitamin B12

Introduction

Vitamin B12, also known as Cobalamin, plays a crucial role in maintaining various bodily functions. As healthcare professionals, it is essential to understand the significance of this vitamin, its clinical applications, and the implications of its deficiency or excess. This article provides an educational overview of Vitamin B12’s background, clinical implications, and factors influencing its levels.

Background of Vitamin B12

Vitamin B12 is a complex corrinoid compound centered on a cobalt atom. It is essential for:

• DNA Synthesis
  
• Red Blood Cell Maturation
  
• Myelin Sheath Formation (nerve health)
  
  

Dietary Sources: Meat, eggs, dairy.
Storage: Primarily in the liver and bone marrow.
Absorption: Requires Intrinsic Factor (from gastric parietal cells) and uptake in the ileum via transcobalamin receptors.

Vitamin B12 Ranges

• Standard Range: 200–1,100 pg/mL (147.6–811.6 pmol/L)
  
• Optimal Range: 545–1,100 pg/mL (402.1–811.6 pmol/L)
  
  

In symptomatic patients, low serum B12 warrants further testing (e.g., methylmalonic acid) to gauge tissue deficiency.

Clinical Implications of Vitamin B12 Levels

Low Vitamin B12 Levels

Deficiency may arise from poor intake (e.g., strict vegan diets) or malabsorption:

• Celiac Disease
  
• Pancreatic Insufficiency
  
• Hypochlorhydria / Acid-Blocking Medications
  
• Gastric Bypass Surgery
  
• Small Intestine Bacterial Overgrowth
  
  

Consequences:

• Megaloblastic Anemia
  
• Peripheral Neuropathy
  
• Cognitive Impairment
  
• Elevated homocysteine (cardiovascular risk)
  
  

High Vitamin B12 Levels

Paradoxical elevations can signal:

• Functional Deficiency: Poor cellular uptake
  
• Chronic Myeloproliferative Neoplasm
  
• Liver Dysfunction
  
• Renal Insufficiency
  
• Recent B12 injections or TPN
  
  

Interfering Factors and Drug Associations

• Chronic Alcoholism: Impairs release from food
  
• Metformin: Induces malabsorption
  
• Proton-Pump Inhibitors (e.g., Omeprazole): Reduce gastric acid, impairing B12 release
  
• H2 Blockers / Antacids: Similar effect with long-term use
  
  

Conclusion

In conclusion, a comprehensive evaluation by a functional medicine practitioner integrates Vitamin B12 assessment into a holistic care model addressing digestive health, nutrient absorption, and cellular balance. By combining precise biomarker profiling with targeted IV therapy and regenerative medicine services, we empower patients to restore metabolic resilience and optimize wellness. Call 904-799-2531 or schedule online to begin your personalized care.

Further Reading

1. Stabler SP. “Clinical practice. Vitamin B12 deficiency.” N Engl J Med. 2013;368(21):2041–2048. PubMed: https://pubmed.ncbi.nlm.nih.gov/23720705/
   
2. O’Leary F, Samman S. “Vitamin B12 in health and disease.” Nutrients. 2010;2(3):299–316. PubMed: https://pubmed.ncbi.nlm.nih.gov/23842974/
3. Green R. “Vitamin B12 deficiency from the perspective of a practicing hematologist.” Blood. 2017;129(19):2603–2611. PubMed: https://pubmed.ncbi.nlm.nih.gov/28339694/