Clinical relevance of low serum vitamin B12 concentrations in older people: the Banbury B12 study.
BACKGROUND
low vitamin B12 concentrations are common in older people, but the clinical relevance of biochemical evidence of vitamin B12 deficiency in the absence of anaemia is uncertain.


OBJECTIVE
to examine associations of cognitive impairment, depression and neuropathy with blood measurements of vitamin B12 and folate status in older people.


METHODS
cross-sectional study in general practice in Banbury, England.


METHODS
a total of 1,000 individuals aged 75 years or older living in the community.


RESULTS
low vitamin B12 concentrations were identified in 13% of older people and were associated with memory impairment and depression. After adjustment for age, sex and smoking, individuals with vitamin B12 or holotranscobalamin (holoTC) in the bottom compared with top quartiles had a 2-fold risk (OR = 2.17; 95% CI 1.11-4.27) and a 3-fold risk (OR = 3.02; 95% CI 1.31-6.98) of cognitive impairment, respectively. Low vitamin B12 status was also associated with missing ankle tendon jerks but not with depression. Treatment with vitamin B12 for 3 months corrected the biochemical abnormalities but had no effect on any of the clinical measurements.


CONCLUSIONS
low vitamin B12 concentrations are associated with cognitive impairment and missing ankle tendon jerks in older people in the absence of anaemia. Large-scale trials of vitamin B12 supplementation are required to assess the clinical significance of these associations.
Hin
Harold
H
Hightown Surgery, Hightown Gardens, Banbury, UK.
Clarke
Robert
R
Sherliker
Paul
P
Atoyebi
Wale
W
Emmens
Kathleen
K
Birks
Jacqueline
J
Schneede
Joern
J
Ueland
Per M
PM
Nexo
Ebba
E
Scott
John
J
Molloy
Anne
A
Donaghy
Michael
M
Frost
Chris
C
Evans
John Grimley
JG
D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000209:etiology; D003863:Depression / Q000209:etiology; D004739:England / Q000453:epidemiology; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D010523:Peripheral Nervous System Diseases / Q000209:etiology; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000150:complications* / Q000188:drug therapy
D014805:Vitamin B 12