title: Vitamin D deficiency is associated with inflammation in older Irish adults.
abstract: BACKGROUND
  Inadequate vitamin D status is common within elderly populations and may be implicated in the etiology of autoimmune disease and inflammation. Few studies have investigated the relationship between vitamin D status and age-related immune dysfunction in humans.
  
  
  OBJECTIVE
  The aim of this study was to investigate the association between vitamin D status and immune markers of inflammation in a large sample of older adults.
  
  
  METHODS
  An observational investigation of 957 Irish adults (>60 years of age) recruited in Northern Ireland (55°N latitude) as part of the Trinity Ulster Department of Agriculture aging cohort study.
  
  
  METHODS
  We measured serum 25-hydroxyvitamin D (25(OH)D) by liquid chromatography tandem mass spectrometry and serum cytokines IL-6, TNF-α, IL-10, and C-reactive protein (CRP) by ELISA.
  
  
  RESULTS
  Concentrations of IL-6, CRP, and the ratios of IL-6 to IL-10 and CRP to IL-10 were significantly higher in individuals with deficient (<25 nmol/L) serum 25(OH)D compared with those with sufficient (>75 nmol/L) status after adjustment for age, sex, and body mass index (P < .05). Vitamin D status was a significant predictor of the IL-6 to IL-10 cytokine ratio, and those participants defined as deficient were significantly more likely to have an IL-6 to IL-10 ratio >2:1 compared with those defined as sufficient.
  
  
  CONCLUSIONS
  This study demonstrated significant associations between low vitamin D status and markers of inflammation (including the ratio of IL-6 to IL-10) within elderly adults. These findings suggest that an adequate vitamin D status may be required for optimal immune function, particularly within the older adult population.
authors.affiliation: Institute of Molecular Medicine (E.L., A.M.M.), School of Medicine, Trinity College, Dublin, Ireland; Northern Ireland Centre for Food and Health (H.M., M.W., L.H., E.M., J.M.W.W., E.C., J.J.S.), University of Ulster, Coleraine, Londonderry BT52 1SA, Northern Ireland; Department of Clinical Biochemistry (M.H.), St James's Hospital, Dublin, Ireland; and The Mercers Institute for Research on Ageing (M.C.C., C.C.), St James's Hospital, Dublin, Ireland.
authors.forename: E
authors.initials: E
authors.lastname: Laird
authors.forename: H
authors.initials: H
authors.lastname: McNulty
authors.forename: M
authors.initials: M
authors.lastname: Ward
authors.forename: L
authors.initials: L
authors.lastname: Hoey
authors.forename: E
authors.initials: E
authors.lastname: McSorley
authors.forename: J M W
authors.initials: JM
authors.lastname: Wallace
authors.forename: E
authors.initials: E
authors.lastname: Carson
authors.forename: A M
authors.initials: AM
authors.lastname: Molloy
authors.forename: M
authors.initials: M
authors.lastname: Healy
authors.forename: M C
authors.initials: MC
authors.lastname: Casey
authors.forename: C
authors.initials: C
authors.lastname: Cunningham
authors.forename: J J
authors.initials: JJ
authors.lastname: Strain
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009660:Northern Ireland; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*
chemical_list: D015415:Biomarkers; D016207:Cytokines; D014807:Vitamin D; C104450:25-hydroxyvitamin D