title: Suicidal patients are deficient in vitamin D, associated with a pro-inflammatory status in the blood.
abstract: BACKGROUND
  Low levels of vitamin D may play a role in psychiatric disorders, as cross-sectional studies show an association between vitamin D deficiency and depression, schizophrenia and psychotic symptoms. The underlying mechanisms are not well understood, although vitamin D is known to influence the immune system to promote a T helper (Th)-2 phenotype. At the same time, increased inflammation might be of importance in the pathophysiology of depression and suicide. We therefore hypothesized that suicidal patients would be deficient in vitamin D, which could be responsible for the inflammatory changes observed in these patients.
  
  
  METHODS
  We compared vitamin D levels in suicide attempters (n=59), non-suicidal depressed patients (n=17) and healthy controls (n=14). Subjects were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and went through a structured interview by a specialist in psychiatry. 25(OH)D2 and 25(OH)D3 were measured in plasma using liquid-chromatography-mass-spectrometry (LC-MS). We further explored vitamin D's association with plasma IL-1β, IL-6 and TNF-α.
  
  
  RESULTS
  Suicide attempters had significantly lower mean levels of vitamin D than depressed non-suicidal patients and healthy controls. 58 percent of the suicide attempters were vitamin D deficient according to clinical standard. Moreover, there was a significant negative association between vitamin D and pro-inflammatory cytokines in the psychiatric patients. Low vitamin D levels were associated with higher levels of the inflammatory cytokines IL-6 and IL-1β in the blood.
  
  
  CONCLUSIONS
  The suicide attempters in our study were deficient in vitamin D. Our data also suggest that vitamin D deficiency could be a contributing factor to the elevated pro-inflammatory cytokines previously reported in suicidal patients. We propose that routine clinical testing of vitamin D levels could be beneficial in patients with suicidal symptoms, with subsequent supplementation in patients found to be deficient.
authors.affiliation: Department of Clinical Sciences, Lund, Psychiatry, Lund University, 221 85 Lund, Sweden. Electronic address: cecile.grudet@med.lu.se.
authors.forename: Cécile
authors.initials: C
authors.lastname: Grudet
authors.affiliation: Department of Laboratory Medicine, Section for Clinical Chemistry, Malmö, Lund University, 205 02 Malmö, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Malm
authors.affiliation: Department of Clinical Sciences, Lund, Psychiatry, Lund University, 221 85 Lund, Sweden; Psychiatric Clinic, Lund, Region Skåne, Sweden.
authors.forename: Asa
authors.initials: A
authors.lastname: Westrin
authors.affiliation: Department of Psychiatry and Behavioral Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA; Laboratory for Behavioral Medicine, Van Andel Research Institute, Grand Rapids, MI, USA.
authors.forename: Lena
authors.initials: L
authors.lastname: Brundin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood*; D003865:Major Depressive Disorder / Q000097:blood / Q000523:psychology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000523:psychology*; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D059020:Suicidal Ideation; D013406:Suicide, Attempted / Q000523:psychology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000523:psychology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D014807:Vitamin D
keywords: Cytokines; Depression; IL-1β; IL-6; Inflammation; Suicidality; TNF-α; Th-1; Th-2