title: Vitamin D status and physical function in older Finnish people: A one-year follow-up study.
abstract: OBJECTIVE
  The aim was to describe vitamin D status and its association with changes in PF during 12 months in Finnish community-dwelling elderly (≥65 years).
  
  
  RESULTS
  Baseline serum 25-hydroxyvitamin D (25OHD) concentration was measured by enzymeimmunoassay, and participants (n=518) were divided according to 25OHD to three groups (I <50 nmol/l, II 50-74.9 nmol/l, and III ≥75 nmol/l). PF (maximal isometric extension strength of right and left knee, and time in five-repetition sit-to-stand test (5STS) and 10-m walking test) was measured at baseline and after 12 months. 25OHD deficiency (<50 nmol/l) was found in 20.5% of the participants. During a 12-month follow-up, differences in changes in knee extensor strength of right (p=0.044) and left (p=0.010) lower extremity and in 10-m walking test (p=.040) between the groups were significant. According to further pairwise comparisons these differences were between groups I and III (right knee, p=0.036; left knee, p=0.009; 10-m walk, p=0.044), with the exception of left knee extensor strength in which there were also significant difference between groups I and II (p=0.039). All significant differences in changes were in favour of group II or III. Significant differences in changes in knee extensor strengths maintained after adjustments for group (intervention/control), parathyroid hormone, and baseline level of knee extensor strength.
  
  
  CONCLUSIONS
  Prospective analyses showed low 25OHD concentrations (<50 nmol/l) to be associated with deterioration in PF during 12 months compared with high 25OHD concentrations (≥75 nmol/l).
authors: Institute of Clinical Medicine, Family Medicine, University of Turku, Turku, Finland; Härkätie Health Centre, Lieto, Finland; Primary Health Care Unit, Hospital District of Southwest Finland and Satakunta, Turku and Pori, Finland. Electronic address: majosa@utu.fi.
authors: Marika
authors: M
authors: Salminen
authors: Calcium Research Unit, Department of Food and Environmental Sciences, University of Helsinki, Finland.
authors: Pilvi
authors: P
authors: Saaristo
authors: Pori City Hospital, Pori, Finland.
authors: Maritta
authors: M
authors: Salonoja
authors: Institute of Clinical Medicine, Family Medicine, University of Turku, Turku, Finland; Primary Health Care Unit, Hospital District of Southwest Finland and Satakunta, Turku and Pori, Finland.
authors: Sari
authors: S
authors: Vaapio
authors: Institute of Clinical Medicine, Biostatistics, University of Turku, Turku, Finland.
authors: Tero
authors: T
authors: Vahlberg
authors: Calcium Research Unit, Department of Food and Environmental Sciences, University of Helsinki, Finland.
authors: Christel
authors: C
authors: Lamberg-Allardt
authors: Satakunta Central Hospital, Pori, Finland.
authors: Pertti
authors: P
authors: Aarnio
authors: Institute of Clinical Medicine, Family Medicine, University of Turku, Turku, Finland; Faculty of Pharmacy, Division of Social Pharmacy, University of Helsinki, Helsinki, Finland.
authors: Sirkka-Liisa
authors: SL
authors: Kivelä
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D011446:Prospective Studies; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014815:Vitamins / Q000097:blood*; D016138:Walking
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Aged; Elderly; Muscle strength; Physical function; Vitamin D