Vitamin B12 Deficiency in Relation to Functional Disabilities

Nutrients

Breanna S. Oberlin²  Christy C. Tangney¹  Kristin A. R. Gustashaw¹ 

[1] Department of Clinical Nutrition, Rush University Medical Center, 1700 West Van Buren St., Suite 425, Chicago, IL 60612, USA; E-Mails:;Diabetes Research Group, Seattle Institute of Biomedical and Clinical Research, 1660 S. Columbian Way, DPP-151, Seattle, WA 98108, USA; E-Mail:

关键词: vitamin B12 deficiency;    methylmalonic acid;    homocysteine;    peripheral neuropathy;    functional impairment;   

DOI  :  10.3390/nu5114462

来源: mdpi

【 摘 要 】

This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12) deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES) were categorized in relation to three previously used definitions of B12 deficiency: (1) serum B12 < 148 pmol/L; (2) serum B12 < 200 pmol/L and serum homocysteine > 20 μmol/L; and (3) serum B12 < 258 pmol/L or serum methylmalonic acid > 0.21 μmol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living) were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds) (95% confidence intervals), p value: 9.70 (2.24, 42.07), 0.004 and report greater total disability, 19.61 (6.22, 61.86) 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid). Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.