The present status of vitamin B 12 and folic acid deficiency in psychiatric illness.

Abstract

Vitamin B12 Deficiency Among the many causes of organic psychoses are a number of processes which may be cured or arrested by the right treatment and by early recognition. This includes deficiency of vitamin B12. There is, therefore, a temptation to carry out sophisticated tests for vitamin B12 deficiency in all psychiatric patients. However, until cheaper and fully-automated techniques become available, routine vitamin B12 assays cannot be justified in psychiatric patients. At the present time a hemoglobin estimation and a careful inspection of the peripheral blood film by an experienced hematologist appear to be the most economic primary screening test for vitamin B12 deficiency. Nevertheless, psychiatrists should be alert to the possibility of vitamin B12 deficiency in patients with unexplained fatigue and in those with confusional states or dementia of unknown origin. Another presentation may be impotence which sometimes precedes other neurological manifestations of the disease. Even in patients who are not anemic or have no blood film abnormalities (which is uncommon) the possibility of missing cases of hypovitamin B12 deficiency can be further diminished by doing serum B12 assays in patients who are clinically at risk. For example, this includes post-gastrectomy patients, those with a familial history of pernicious anemia and those with an associated auto-immune disorder, such as thyroid disease. Folic Acid Deficiency The available evidence linking folate deficiency with psychiatric disorders is inconclusive. It is probable that the observed excess of folic acid deficiency in psychiatric patients can be explained on the basis of malnutrition, chronic physical illness, alcoholism or other drug usage. An important exception is brain damage and mental retardation in infants with inborn errors of folic acid metabolism. Further evaluation of folate deficiency is indicated, particularly in the affective disorders and in ambulatory, non-institutionalized, epileptic patients receiving anticonvulsant medication.