Prevalence of vitamin B12 deficiency in spinal cord injury.

Objective: To assess the prevalence of vitamin B(12) deficiency in persons with spinal cord injury (SCI) or disease (SCD).

Design: Cross-sectional study with prospective blood collection and retrospective medical record review.

Setting: Regional Veterans Affairs SCI service.

Participants: One hundred six adult men with chronic SCI or SCD and without other acute medical or surgical complications; most had SCI or SCD due to trauma or cervical spinal stenosis.

Interventions: Not applicable.

Main Outcome Measures: Fasting blood samples were obtained at annual evaluation for serum B(12), folic acid, methylmalonic acid (MMA), and homocysteine. Serum levels were analyzed graphically and associated with patient variables by using statistical tests.

Results: The vitamin B(12) level was subnormal in 5.7% of subjects; of those, all had supranormal MMA levels, all were age 40 to 59, most had complete SCI, and 67% had symptoms suggestive of B(12) deficiency. Low-normal B(12) levels were associated with a high prevalence of supranormal MMA. Subjects with either subnormal B(12) or low normal B(12) with supranormal MMA, both suggestive of vitamin B(12) deficiency, comprised 13.3% of the total group of subjects.

Conclusion: Vitamin B(12) deficiency is most common in middle-aged SCI or SCD persons with complete or near-complete spinal cord involvement (ie, American Spinal Injury Association class A-C injuries). Treatment with either parenteral or oral B(12) replacement may optimize health and prevent irreversible neuropsychiatric complications in those with subnormal and low-normal B(12) levels.