Older adult psychiatric inpatients with non-cognitive disorders should be screened for vitamin B12 deficiency.

Objective: Vitamin B12 (B12) deficiency is most prevalent among older adults. Practice guidelines recommend screening older adults with symptoms of cognitive disorder for B12 deficiency. However, guidelines for non-cognitive psychiatric disorders typically do not mention screening older adults for B12 deficiency. The purpose of this study was to determine whether routine screening of older adult psychiatric inpatients for B12 deficiency, regardless of cognitive symptoms, is clinically justified.

Design: We conducted a retrospective chart-review study of consecutive inpatient admissions.

Setting: Older Adult Acute Psychiatric Inpatient Unit at the University of Maryland Medical Center from 10/2007-4/2010.

Participants: Acute psychiatric inpatients aged ≥50 years who met inclusion criteria (N=374).

Measurements: Mean (SD) B12 levels and percentages of probable (<180pg/mL) and possible (180-350pg/mL) B12 deficiency as well as characteristics of patients with probable and possible B12 deficiency compared to patients with optimal B12 levels.

Results: Mean (SD) B12 levels and percentages of probable and possible B12 deficiency, respectively, for cognitive disorder patients [468 (284) pg/mL, 7.8 % (n=5) and 29.7% (n=19)] and for non-cognitive disorder patients [481(268) pg/mL, 4.8 %(n=15) and 33.2%( n=103)] were not significantly different (t=0.339, df=372, P=0.735; χ2=1.084, df=2, P=0.582, respectively).

Conclusion: Considering the potential benefits and low costs of screening and treatment, we conclude that it is justified to routinely screen older adult psychiatric inpatients for B12 deficiency whether or not cognitive disorder symptoms are present.