The prevalence of vitamin B12 deficiency in persons with SCI is reported to be between 5.7% and 19% (Petchkrua et al. 2002). Symptoms may include declining gait, depression or fatigue, upper limb weakness, memory loss and worsening pain (Petchkrua et al. 2002; Petchkrua et al. 2003). Vitamin B12 deficiency usually responds to supplementation.
Petchkrua et al. (2002) conducted a retrospective chart review of patients with SCI who had received serum vitamin B12 testing over a 10 year period. The most common symptoms among subjects identified as having deficient, subnormal or low normal vitamin B12 levels were declining gait, depression, fatigue, upper limb weakness, memory loss or worsening pain. In this report, greater than half of the cases of probable vitamin B12 deficiency occurred in young persons with no known risk factors. Neurologic and/or psychiatric symptoms improved in 88% of SCI subjects following high-dose oral or monthly parenteral vitamin B12 supplementation. It is recommended that clinicians conduct early screening and treatment of vitamin B12 deficiency.
In a follow-up cross-sectional study, Petchkrua et al. (2003) prospectively collected blood samples and reviewed medical records to assess the prevalence of vitamin B12 deficiency in persons with SCI. Biochemical vitamin B12 deficiency was reported in 13% of the subjects. While hematologic abnormalities were infrequent, neuropsychiatric symptoms were observed in half of the subjects. The age range most associated with vitamin B12 deficiency was 40-59 years; among subjects older than 59 years, 9% had B12 deficiency. No deficiency was noted in subjects within the age range of 20-39 years. Deficiency was more predominant in subjects with a complete SCI.
Given the potential for permanent neurological deficits, the relatively low cost of screening and the low cost and high efficacy of high-dose oral supplementation, Petchkrua et al. (2002) suggest that clinicians conduct early screening and treatment of vitamin B12 deficiency. Additional investigations into the predisposing risk factors for vitamin B12 deficiency in persons with SCI are warranted.