title: Vitamin D deficiency intensifies deterioration of risk factors, such as male sex and absence of vision, leading to increased postural body sway.
abstract: BACKGROUND
  Due to inconsistent findings, the influence of vitamin D on postural body sway (PBS) is currently under debate. This study evaluated the impact of vitamin D on PBS with regards to different foot positions and eye opening states in community-dwelling older individuals.
  
  
  METHODS
  In a cross-sectional study, we assessed PBS in 342 older individuals (264 females [average age (± SD): 68.3 ± 9.0 years], 78 males [65.7 ± 9.6 years]). A detailed medical history and vitamin D level were obtained for each individual. Fall risk was evaluated using the New York-Presbyterian Fall Risk Assessment Tool (NY PFRA). PBS parameters (area, distance, velocity, frequency) were evaluated on a pressure plate with feet in closed stance (CS) or hip-width stance (HWS), open eyes and closed eyes. Statistical analysis included logarithmic mixed models for repeated measures with the MIXED model procedure to test the influence of vitamin D (categorized in <10 μg/l, 10-20 μg/l, 21-30 μg/l, >30 μg/l), foot position, eye opening state, age, sex and frequency of physical activity on PBS.
  
  
  RESULTS
  Vitamin D was not an independent risk factor for falls experienced in the last 12 months. Nonetheless, PBS was higher in patients with vitamin D deficiency (<10 μg/l) in HWS (A/P p=0.028 and area p=0.037). Additionally, vitamin D deficiency intensified the deleterious effects of male sex (distance p=0.002) and absence of vision (area p<0.001) on PBS.
  
  
  CONCLUSIONS
  Independent risk factors for increased PBS like male sex and absence of vision are additionally compromised by vitamin D deficiency.
authors.affiliation: Department of Osteology and Biomechanics; University Medical Center Hamburg-Eppendorf, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Krause
authors.forename: Wilma
authors.initials: W
authors.lastname: Anschütz
authors.forename: Eik
authors.initials: E
authors.lastname: Vettorazzi
authors.forename: Stefan
authors.initials: S
authors.lastname: Breer
authors.forename: Michael
authors.initials: M
authors.lastname: Amling
authors.forename: Florian
authors.initials: F
authors.lastname: Barvencik
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005528:Foot / Q000503:physiopathology*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014786:Vision Disorders; D014808:Vitamin D Deficiency / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology
keywords: Fall risk; Postural balance; Sex; Visual impairment; Vitamin D