Vitamin B12 levels are low in hospitalized psychiatric patients

Background: Deficiency of vitamin B12, a key component in the catabolism of monoamines, is associated with various neuropsychiatric disorders and may be more frequent in hospitalized patients. Method: We reviewed vitamin B12 assays performed in a laboratory of a large Israeli psychiatric hospital ov er a 23-month period to examine prevalence of low values and compared vitam in B12 deficient patients to those with normal levels on various parameters . In addition, vitamin levels in a random sample of in-patients whose nutri tional intake was determined, were examined. Results: 20% of 644 vitamin B1 2 assays were in the low ( 200 pg/ml) and 10% in the deficient (< 160 pg/ml ) range. 24 selected vitamin B12 deficient patients (70.8% with diagnosis o f schizophrenia) did not differ from controls (N=35) in age, sex ratio, hem oglobin concentration, MCV, diagnostic distribution or number and length of hospitalizations, but had slightly lower (but normal) mean folate levels. Rates of vitamin B12 deficiency in the patient sample, whose nutritional in take was adequate, did not differ significantly from those in the laborator y survey. Conclusion: Vitamin B12 deficiency is common in chronically ill p sychotic patients with adequate nutrition and is not readily detected by ro utine hematology tests.