Vitamin B12 deficiency and nervous system disease in HIV infection.

BACKGROUND: Vitamin B12 deficiency may result in a number of neurological and neuropsychiatric disorders. Patients with human immunodeficiency virus type 1 (HIV-1) infection may have a high rate of vitamin B12 deficiency and nervous system disease. Vitamin B12 deficiency may contribute to neurological disease in HIV-1-infected individuals.

OBJECTIVE: To evaluate the possible contribution of vitamin B12 deficiency to neurological disease in HIV-1-infected individuals.

MAIN OUTCOME MEASURES: Comparison of serum vitamin B12 levels with neurological, neuropsychological, and mood state abnormalities in 153 HIV-1-positive subjects and 57 high-risk seronegative controls. A subgroup of 67 subjects underwent additional extensive clinical neurophysiological, cerebrospinal fluid, and magnetic resonance imaging evaluations.

RESULTS: No statistically significant relationships were noted between vitamin B12 levels and abnormalities on any of the measures examined.

CONCLUSIONS: This study does not indicate an important role for vitamin B12 deficiency in the neurological disease of HIV-1 infection.