Research published in Neuroscience Bulletin (2009; Volume 25, Issue 4, Pages 209–215) examined the relationship between vitamin B12 deficiency and overall health in elderly patients. The study included 827 participants with an average age of 77 years, all of whom were older than 60. Among these patients, 19.7% were found to be vitamin B12 deficient.
Vitamin B12 deficiency was associated with a wide range of health concerns. Neurological findings were common and included symptoms such as unsteadiness in the dark, parkinsonian features, and hypopallesthesia (reduced vibration and position sense). The vitamin B12–deficient group also showed higher rates of diabetes, heart disease, cerebral ischemia, hypertension, and gastrointestinal disorders compared with patients who were not deficient.
Severe vitamin B12 deficiency can lead to pernicious anemia, a form of megaloblastic anemia characterized by abnormally large red blood cells. However, neurological symptoms often appear well before anemia develops. In this study, only 9.8% of vitamin B12–deficient patients exhibited megaloblastic anemia, highlighting that neurologic impairment may be present even in the absence of classic hematologic findings.
