As known, the determination of B12 levels in patients with dementia is a routine practice meant to identify a reversible cause of the disorder. But data conflict regarding the effects of B12 replacement on the dementia.
Researchers at Southern Illinois University School of Medicine in Springfield, Illinois, reviewed the clinical courses of patients (N=33) who presented to their dementia clinic and were found to have B12 deficiency, defined as a low B12 level and elevated methylmalonic acid (MMA) and homocysteine. A comparison group of patients with probable Alzheimer's disease, matched for age, sex, and baseline Mini-Mental State Examination (MMSE) score, were also identified.
The mean age of the study patients was 78.8 +/-8.8; mean MMSE was 21.6 +/-4.8; and mean B12 level was 153.3 +/-33.3 pg/ml. The researchers treated them with B12 and followed them for a mean duration of 26.6 months. After data analysis, there was found no significant difference between patients and controls in the rate of decline of the MMSE score (-0.19 +/-0.37 vs -0.12 +/-0.16, P=
0.45); absolute change in MMSE score (-4.3 +/-4.8 vs -6 +/-7.8, P=
0.17); or the number whose MMSE scores were stable or improved (30% vs 27%, P=
0.78). Further, none experienced a dramatic clinical reversal of their dementia with B12 replacement.