Risk Factors and Comorbidities Associated With Vitamin B₁₂ Deficiency in an Adult Population

Vitamin B₁₂ deficiency (B12D) is associated with multiple risk factors and comorbidities; however, there are no firm guidelines regarding screening for B12D in the population at risk. We aimed to identify the risk factors and comorbidities associated with B12D in an adult population.

Retrospective review of entire cohort of adult patients who received outpatient medical care in our large urban tertiary healthcare system between January 1, 2011, and December 31, 2020. Variables were compared between the group who had B12D and those who did not (NoB12D).

Patients with B12D (n = 2666) were younger than NoB12D group (n = 2334; 62.2 ± 18.5 vs 76.5 ± 7.6 year; P < .001). There were significantly higher associations of certain factors in the B12D group compared to NoB12D group, such as female sex, recreational drug use, congestive heart failure (CHF), cerebrovascular accident (CVA), chronic obstructive pulmonary disease (COPD), asthma, peripheral neuropathy (PN), subacute combined degeneration of spinal cord (SCD), dementia, mild cognitive impairment (MCI), gastroesophageal reflux disorder (GERD), gastritis, inflammatory bowel disease (IBD), small bowel resection (SBR), colorectal surgery (CRS), bariatric surgery (BS), depression, bipolar disorder, anxiety disorder, schizophrenia, anemia, use of non-steroidal anti-inflammatory drug (NSAID), proton pump inhibitor (PPI), histamin-2 receptor antagonist (H2RA), and lithium. Compared to White race, Black and Hispanic races had higher odds of B12D (OR = 1.43, 95% CI = 1.02-2.01; P = .040, and OR = 3.15, 95% CI = 2.23-4.45; P < .001, respectively). Additional comorbidities with greater odds of B12D included respiratory disorders (COPD and asthma; OR = 1.41, 95% CI = 1.12-1.78; P = .003), anemia (OR = 253.72, 95% CI = 164.66-390.93; P < .001), neurological diseases (PN and SCD; OR = 2.78, 95% CI = 2.16-3.58; P < .001), cognitive disorders (dementia and MCI; OR = 3.37, 95% CI = 2.40-4.74; P < .001), gastrointestinal disorders (GERD, gastritis, IBD, SBR, CRS, and BS; OR = 2.38, 95% CI = 1.95-2.90; P < .001), PPI use (OR = 2.81, 95% CI = 1.88-4.20; P < .001), and NSAID use (OR = 1.40, 95% CI = 1.08-1.81; P = .011).

Younger age, female sex, Black and Hispanic races, recreational drug use, CHF, CVA, COPD, asthma, PN, SCD, dementia, MCI, GERD, IBD, SBR, colorectal surgery, bariatric surgery, depression, bipolar disorder, anxiety disorder, schizophrenia, anemia, use of PPI, H2RA, NSAIDs, and lithium are associated with B12D.