Vitamin B12

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.