Vitamin B12 deficiency: testing and treatment.

Area of Science:

• Clinical Biochemistry
• Hematology

Background:

• Vitamin B12 deficiency can manifest with various clinical signs and symptoms.
• Risk factors include inadequate dietary intake and malabsorptive conditions, necessitating vigilance.

Purpose of the Study:

• To outline the recommended approach for vitamin B12 testing.
• To guide the interpretation of test results and subsequent management.

Main Methods:

• Total serum vitamin B12 is the primary diagnostic test.
• Active B12 testing is utilized for indeterminate results or during pregnancy.
• Methylmalonic acid and homocysteine levels serve as secondary markers when primary tests are inconclusive.

Main Results:

• Total serum B12 is the standard initial screening method.
• Active B12 offers additional diagnostic value in specific scenarios.
• Elevated methylmalonic acid or homocysteine may indicate B12 deficiency but can be affected by other conditions.

Conclusions:

• Testing strategies should align with clinical suspicion and risk factors.
• A stepwise approach using total B12, active B12, and other biomarkers ensures accurate diagnosis.
• Confirmed vitamin B12 deficiency necessitates tailored supplementation based on cause, severity, and patient preference.