Vitamin D status and measures of cognitive function in healthy older European adults.
OBJECTIVE
Data from human studies that have investigated the association between vitamin D status and cognitive function in elderly adults are conflicting. The objective of this study was to assess vitamin D status (reflected by serum 25-hydroxyvitamin D (25(OH)D)) in older European subjects (n=387; aged 55-87 years) and examine its association with measures of cognitive function.


METHODS
Serum 25(OH)D was assessed using enzyme-linked immunosorbent assay, whereas measures of cognitive function were assessed using a comprehensive Cambridge Neuropsychological Testing Automated Battery (CANTAB).


RESULTS
In all, 12, 36 and 64% of subjects had serum 25(OH)D concentrations <30, <50 and <80 nmol/l, respectively, throughout the year. Serum 25(OH)D was significantly and inversely correlated with four assessments within the spatial working memory (SWM) test parameter (SWM between errors (r=-0.166; P=0.003); SWM between errors 8 boxes (r=-0.134; P=0.038); SWM strategy (r=-0.246; P<0.0001); and SWM total errors (r=-0.174; P<0.003)). When subjects were stratified on the basis of tertiles (T) of serum 25(OH)D (<47.6 (T(1)); 47.6-85.8 (T(2)); and >85.8 (T(3)) nmol/l), fewer errors in SWM test scores occurred in subjects in the third T when compared with the first T (P<0.05-0.084). Stratification by sex showed that these differences between tertiles strengthened (P<0.001-0.043) in the females, but the differences were not significant (P>0.6) in males.


CONCLUSIONS
Vitamin D insufficiency, but not deficiency, is widespread in the older population of several European countries. Low vitamin D status was associated with a reduced capacity for SWM, particularly in women.
Seamans
K M
KM
School of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
Hill
T R
TR
Scully
L
L
Meunier
N
N
Andrillo-Sanchez
M
M
Polito
A
A
Hininger-Favier
I
I
Ciarapica
D
D
Simpson
E E A
EE
Stewart-Knox
B J
BJ
O'Connor
J M
JM
Coudray
C
C
Cashman
K D
KD
D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002112:Calcifediol / Q000097:blood*; D003071:Cognition; D003072:Cognition Disorders / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000097:blood / Q000150:complications / Q000453:epidemiology; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests; D009752:Nutritional Status; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000453:epidemiology
D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol