Vitamin B12 and Folate Deficiency Screening is Essential
In a 12-year-old boy with mild iron deficiency anemia experiencing cognitive symptoms (difficulty focusing and remembering), you should check vitamin B12 and folate levels, as these deficiencies can cause both anemia and neurological symptoms including memory loss and concentration difficulties. 1
Primary Deficiencies to Screen Beyond Iron
Vitamin B12 Deficiency
- Vitamin B12 deficiency can cause severe megaloblastic anemia and neurological deficits including memory loss, which could be erroneously attributed to other causes in children with known anemia 1
- The cognitive symptoms (difficulty focusing and remembering) are particularly concerning for B12 deficiency, as this vitamin is critical for neurological function 1, 2
- B12 deficiency may occur if there is inadequate consumption of animal protein or medical foods fortified with B12 1
- Serum vitamin B12 levels should be measured, especially when macrocytic anemia is present, but can occur even with normal MCV 2
Folate Deficiency
- Folate deficiency is another nutritional cause of anemia that must be excluded 1
- Like B12 deficiency, folate deficiency causes megaloblastic anemia and can present with macrocytosis 1, 2
- Serum folate levels should be checked alongside B12 when evaluating unexplained anemia 2, 3
Diagnostic Algorithm
Initial Workup Should Include:
- Complete blood count with red cell indices (MCV, RDW) to characterize the anemia type 1, 3
- Serum ferritin and transferrin saturation to confirm iron deficiency 1
- Serum vitamin B12 and folate levels given the cognitive symptoms 1, 2
- Reticulocyte count to assess bone marrow response 1, 3
Key Laboratory Interpretation:
- Macrocytosis (elevated MCV) with macro-ovalocytes and hypersegmented neutrophils suggests B12 or folate deficiency 2
- However, normal MCV does not exclude B12 or folate deficiency, as mixed deficiencies can occur 1
- Less than 50% of children with anemia are actually iron deficient, making evaluation for other causes critical 1
Critical Clinical Pitfall
The most important caveat is that cognitive symptoms (memory loss, difficulty concentrating) in a child with anemia should immediately raise suspicion for vitamin B12 deficiency, as these neurological symptoms may not be fully reversible even after correction 1, 4. Do not assume all symptoms are due to iron deficiency alone, especially when cognitive complaints are prominent.
Additional Considerations
Other Potential Deficiencies:
- Lead poisoning should be considered as it can cause both anemia and cognitive impairment 1
- Chronic inflammation or infection can cause anemia of chronic disease 1
- Hereditary conditions (thalassemia, sickle cell disease) should be excluded if family history or ethnic background suggests risk 1