title: Vitamin D is not associated with incident dementia or cognitive impairment: an 18-y follow-up study in community-living old men.
abstract: Background:Vitamin D has been implicated as being important for maintaining cognitive function in old age. Results from longitudinal studies examining the association of vitamin D with incident dementia and cognitive impairment have been inconsistent.Objective:We investigated the relation between vitamin D, assessed in 3 different ways, and the risk of dementia.Design:We measured plasma 25-hydroxyvitamin D [25(OH)D] with the use of high-performance liquid chromatography-mass spectrometry, assessed dietary vitamin D intake with the use of 7-d dietary records, and created a vitamin D-synthesis genetic risk score (GRS) at baseline (1991-1995) in a cohort of 1182 Swedish men (mean age: 71 y). In a maximum of 18 y (median: 12 y) of follow-up, 116 men developed Alzheimer disease, 64 men developed vascular dementia, and 250 men developed all-cause dementia. An additional 80 men declined in cognitive function as assessed with the use of the Mini-Mental State Examination. Adjusted HRs and ORs were calculated with the use of Cox and logistic regressions.Results:The mean ± SD plasma 25(OH)D concentration was 68.7 ± 19.1 nmol/L. Plasma 25(OH)D, dietary vitamin D intake, and vitamin D-synthesis GRS were not associated with any cognitive outcomes (crude and adjusted HRs and ORs were ∼1.0 for all continuous exposures). The adjusted HR for all-cause dementia was 0.88 (95% CI: 0.59, 1.31) in men with plasma 25(OH)D concentrations ≤50 compared with >75 nmol/L. The adjusted HR for all-cause dementia was 0.92 (95% CI: 0.63, 1.32) for the lowest compared with highest tertiles of vitamin D intake. The adjusted HR for the continuous GRS for all-cause dementia was 1.04 (95% CI: 0.91, 1.19).Conclusion:In this cohort study, we show that there is no association between baseline vitamin D status and long-term risk of dementia or cognitive impairment over an 18-y period of time.
authors.affiliation: Departments of Public Health and Caring Sciences/Clinical Nutrition and Metabolism, erika.olsson@pubcare.uu.se liisa.byberg@surgsci.uu.se.
authors.forename: Erika
authors.initials: E
authors.lastname: Olsson
authors.affiliation: Surgical Sciences, Orthopedics, erika.olsson@pubcare.uu.se liisa.byberg@surgsci.uu.se.
authors.forename: Liisa
authors.initials: L
authors.lastname: Byberg
authors.affiliation: Departments of Public Health and Caring Sciences/Clinical Nutrition and Metabolism.
authors.forename: Brita
authors.initials: B
authors.lastname: Karlström
authors.affiliation: Departments of Public Health and Caring Sciences/Clinical Nutrition and Metabolism.
authors.forename: Tommy
authors.initials: T
authors.lastname: Cederholm
authors.affiliation: Medical Sciences, Clinical Pharmacogenomics and Osteoporosis, and.
authors.forename: Håkan
authors.initials: H
authors.lastname: Melhus
authors.affiliation: Departments of Public Health and Caring Sciences/Clinical Nutrition and Metabolism.
authors.forename: Per
authors.initials: P
authors.lastname: Sjögren
authors.affiliation: Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Kilander
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D003071:Cognition; D060825:Cognitive Dysfunction / Q000097:blood* / Q000209:etiology; D015331:Cohort Studies; D003704:Dementia / Q000097:blood* / Q000453:epidemiology / Q000209:etiology / Q000235:genetics; D015930:Diet Records; D005500:Follow-Up Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D016016:Proportional Hazards Models; D013548:Sweden / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000150:complications
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-hydroxyvitamin D; Alzheimer disease; Mendelian randomization; cognitive impairment; cohort; dementia; vascular dementia; vitamin D