THE EFFECT OF VITAMIN-B-12 DEFICIENCY ON OLDER VETERANS AND ITS RELATIONSHIP TO HEALTH

OBJECTIVE: To examine the effect of vitamin B-12 deficiency on older v eterans and its relationship to general health and cognitive impairmen t. DESIGN: Cross-sectional study. SETTING: Oklahoma City Veterans Affa irs Medical Center. PARTICIPANTS: Data for this research were obtained from 303 ambulatory, older veterans who used the outpatient laborator ies of the Oklahoma City Department of Veterans Affairs Medical Center . Subjects were included in the study if they were 65 years of age and older and if they had no known diagnosis associated with B-12 deficie ncy. The sample in this study consisted of 301 men and 2 women aged 65 to 89 years. MEASUREMENTS: This study used two separate measurements of vitamin B-12 deficiency: (1) a strict definition of B-12 deficiency (serum B-12 level < laboratory norm) and (2) a broader definition of B-12 deficiency serum B-12 level < laboratory norm or laboratory norm < B,, < 300 pg/mL and methyl malonic acid (MMA) or homocysteine JHC) e levated by more than two standard deviations). The laboratory norm is 200 pg/mL. The dependent variables were measures of cognitive impairme nt and general health. Cognitive impairment was measured using the Fol stein Mini-Mental State Examination (MMSE) and general health was meas ured using the RAND 36-Item Health Survey Version 1.0. The control var iables for this study were the subjects' daily alcohol intake, daily i ntake of a vitamin/mineral supplement, annual income, and level of edu cation. RESULTS/CONCLUSIONS: Nineteen subjects (6%) were vitamin B-12- deficient as measured by the strict definition of B-12 deficiency (ser um B-12 level < laboratory norm), and 49 subjects (16%) were vitamin B -12-deficient as measured by the broader definition of B-12 deficiency jserum B12 level < laboratory norm or laboratory norm < B-12 < 300 pg /mL and MMA or HC elevated by more than two standard deviations). Vita min B-12 level decreases as age increases. Of the nine general health outcomes measured by using the RAND 36-Item Health Survey, only bodily pain is associated with vitamin B-12 deficiency, and only then when B -12 deficiency is measured as serum B-12 level < laboratory norm, the strict definition of B-12 deficiency. Vitamin B-12-deficient subjects experience more bodily pain than those with normal vitamin B-12 levels . There is a significant difference between B-12 deficient subjects an d B-12 normal subjects on cognitive impairment, with B,, normal subjec ts indicating less cognitive impairment, only when B-12 deficiency is measured as B-12 level < laboratory norm, the strict definition of B-1 2 deficiency. The broader measurement of vitamin B-12 deficiency (i.e. , serum B-12 level < laboratory norm or laboratory norm < B-12 < 300 p g/mL and MMA or HC elevated by more than two standard deviations) is n ot a significant correlate of cognitive impairment and general health.