From the Research
Vitamin B12 deficiency can cause leukopenia, a condition characterized by a low white blood cell count, as it impairs the normal production of white blood cells in the bone marrow. This occurs because vitamin B12 is essential for DNA synthesis and cell division, processes critical for the production of all blood cells 1. The condition typically develops gradually as B12 stores become depleted, often alongside other hematological abnormalities like anemia and thrombocytopenia.
Key Points to Consider
- Vitamin B12 deficiency can lead to pancytopenia, macrocytosis, hypersegmentation of neutrophils, and hypercellular bone marrow with blastic differentiation, which can sometimes be misdiagnosed as myelodysplastic syndromes or acute leukemia 2.
- Treatment involves vitamin B12 supplementation, typically through injections of cyanocobalamin or hydroxocobalamin, especially in cases of malabsorption.
- For severe deficiency, initial dosing might include daily or weekly injections (1000 mcg) until blood counts normalize, followed by monthly maintenance injections.
- Oral supplements (1000-2000 mcg daily) may be sufficient for dietary deficiency.
- Blood counts usually begin improving within days to weeks of starting replacement therapy.
Importance of Early Diagnosis and Treatment
It's crucial to identify and address the underlying cause of B12 deficiency, which may include pernicious anemia, gastrointestinal disorders, or strict vegetarian diets 3. Failure to diagnose B12 deficiency can have dire consequences, usually neurological. The features of B12 deficiency are variable and may be atypical, making timely diagnosis important 3.
Recent Consensus on Diagnosis and Treatment
A recent Delphi expert consensus highlights the need for educational and organizational changes in current medical practices for diagnosing and treating B12 deficiency, emphasizing the importance of recognizing clinical symptoms and using serum B12 concentration and methylmalonic acid or homocysteine as diagnostic markers 1. The consensus also supports the use of parenteral B12 as the first choice for patients with acute and severe manifestations of B12 deficiency, with high-dose oral B12 considered for long-term treatment.