title: Vitamin D levels appear to be normal in Danish patients attending secondary care for low back pain and a weak positive correlation between serum level Vitamin D and Modic changes was demonstrated: a cross-sectional cohort study of consecutive patients with non-specific low back pain.
abstract: BACKGROUND
  Hypovitaminosis D has previously been reported in both the general population, in people with chronic musculoskeletal pain, and in people with low back pain (LBP). Myopathy-related symptoms such as diffuse bone and muscle pain, weakness and paresthesia in the legs, have also been observed in people with non-specific LBP and associations with low levels of Vitamin D have been suggested. The objectives of this study were to investigate (1) Vitamin D levels in patients seeking care for LBP in a Danish out-patient secondary care setting, and (2) their possible relationship with myopathy-related symptoms, Body Mass Index (BMI), and Modic changes.
  
  
  METHODS
  A total of 152 consecutive patients with non-specific LBP participated in a cross-sectional study. Participants were recruited at The Spine Centre of Southern Denmark during springtime 2011. Individual serum levels of 25-Hydroxyvitamin-D were determined using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Information about symptoms, height, and weight were collected from electronic questionnaires completed by the participants. All patients had an MRI from which Modic changes were identified. Correlations between Vitamin D level and pain, paresthesia, weakness in the legs, BMI or Modic changes were described using correlation coefficients and odds ratios obtained from logistic regression.
  
  
  RESULTS
  Two-thirds of the included patients with LBP had normal Vitamin D levels of >50 nmol/L. No correlations were seen between Vitamin D deficiency and gender, age, back pain intensity, leg pain intensity, and duration of pain. Statistically significant, but low, correlation coefficients were found between Vitamin D levels and BMI as well as Modic changes. Low Vitamin D levels and Modic changes were statistically significantly associated with an odds ratio of 0.30 (95% CI 0.12; 0.75) while weakness, paresthesia and widespread pain were not.
  
  
  CONCLUSIONS
  In patients seeking care for low back pain in a Danish outpatient clinic, Vitamin D deficiency was not common. Whether patients who are overweight or who have Modic changes might represent subgroups of people for whom their LBP may be associated with Vitamin D levels, needs further investigation.
authors.affiliation: Research Unit, Spine Centre of Southern Denmark, Part of Clinical Locomotion Network, Hospital Lillebaelt, Institute of Regional Health Services, University of Southern Denmark, Oestre Hougvej 55, Middelfart, DK-5500, Denmark. jannick.vaaben.johansen@rsyd.dk
authors.forename: Jannick Vaaben
authors.initials: JV
authors.lastname: Johansen
authors.forename: Claus
authors.initials: C
authors.lastname: Manniche
authors.forename: Per
authors.initials: P
authors.lastname: Kjaer
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002853:Chromatography, Liquid; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D017116:Low Back Pain / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000453:epidemiology; D016017:Odds Ratio; D010147:Pain Measurement; D010292:Paresthesia / Q000453:epidemiology; D012307:Risk Factors; D063127:Secondary Health Care; D011795:Surveys and Questionnaires; D053719:Tandem Mass Spectrometry; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D