Prevalence of vitamin d insufficiency in patients with Parkinson disease and Alzheimer disease.
BACKGROUND
A role for vitamin D deficiency in Parkinson disease (PD) has recently been proposed.


OBJECTIVE
To compare the prevalence of vitamin D deficiency in a research database cohort of patients with PD with the prevalence in age-matched healthy controls and patients with Alzheimer disease (AD).


METHODS
Survey study and blinded comparison of plasma 25-hydroxyvitamin D (25[OH]D) concentrations of stored samples in a clinical research database at Emory University School of Medicine.


METHODS
Referral center (PD and AD patients), primary care clinics, and community setting (controls).


METHODS
Participants were recruited into the study between May 1992 and March 2007. Every fifth consecutively enrolled PD patient was selected from the clinical research database. Unrelated AD (n = 97) and control (n = 99) participants were randomly selected from the database after matching for age, sex, race, APOE genotype, and geographic location.


METHODS
Prevalence of suboptimal vitamin D and mean 25(OH)D concentrations.


RESULTS
Significantly more patients with PD (55%) had insufficient vitamin D than did controls (36%) or patients with AD (41%; P = .02, chi(2)test). The mean (SD) 25(OH)D concentration in the PD cohort was significantly lower than in the AD and control cohorts (31.9 [13.6] ng/mL vs 34.8 [15.4] ng/mL and 37.0 [14.5] ng/mL, respectively; P = .03).


CONCLUSIONS
This report of 25(OH)D concentrations in a predominantly white PD cohort demonstrates a significantly higher prevalence of hypovitaminosis in PD vs both healthy controls and patients with AD. These data support a possible role of vitamin D insufficiency in PD. Further studies are needed to determine the factors contributing to these differences and elucidate the potential role of vitamin D in pathogenesis and clinical course of PD.
Department of Neurology, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, GA 30329, USA. mevatt@emory.edu
Marian L
ML
Evatt
Mahlon R
MR
Delong
Natasha
N
Khazai
Ami
A
Rosen
Shirley
S
Triche
Vin
V
Tangpricha
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000378:metabolism* / Q000503:physiopathology; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology* / Q000378:metabolism* / Q000503:physiopathology; D015995:Prevalence; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000208:ethnology; D044465:White People
D014807:Vitamin D; C104450:25-hydroxyvitamin D