title: High prevalence of vitamin D deficiency in women with breast cancer: The first Chilean study.
abstract: BACKGROUND
  Breast cancer (BC) is the leading cause of female death from malignancy worldwide. One factor that has been associated to a higher incidence and poor prognosis is a Vitamin D deficiency (measured as 25-Hydroxi-Vitamin D (25OHD)). Our aim was to determine 25OHD levels in serum samples of Chilean BC patients before endocrine therapy and its association to clinical parameters at the time of diagnosis.
  
  
  METHODS
  We analyzed clinical records of 105 women, evaluated at the Cancer Center of the Pontificia Universidad Católica de Chile. Serum levels of 25OHD were determined using a chemiluminescent microparticle immunoassay.
  
  
  RESULTS
  The prevalence of vitamin D deficiency before endocrine therapy was of 70.5%. Only 7% of our patients showed sufficient vitamin D levels at the beginning of the endocrine treatment. There was a significant correlation found between age and 25OHD levels, and also between body fat percentage and 25OHD levels (r(2) = 0.04; p = 0.021; r(2) = 0.028; p = 0.0432, respectively). Summer 25OHD levels were significantly higher than winter levels (p = 0.0322).
  
  
  CONCLUSIONS
  Vitamin D deficiency is highly prevalent in Chilean BC women before endocrine therapy and 25OHD levels are inversely correlated to the age and body fat percentage of patients. Further studies are needed to determine causal relationship between vitamin D levels and BC development and outcome.
authors.affiliation: Hematology-Oncology Department, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avda. Diagonal Paraguay 319, Santiago, Chile.
authors.forename: Francisco
authors.initials: F
authors.lastname: Acevedo
authors.affiliation: Obstetrics and Gynecology Department, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O'Higgins 340, Santiago, Chile.
authors.forename: Victoria
authors.initials: V
authors.lastname: Pérez
authors.affiliation: Hematology-Oncology Department, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avda. Diagonal Paraguay 319, Santiago, Chile.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Pérez-Sepúlveda
authors.affiliation: Endocrinology Department, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O'Higgins 340, Santiago, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Florenzano
authors.affiliation: Center of Investigative and Translational Oncology, Pontificia Universidad Católica de Chile, Avda. Libertador Bernardo O'Higgins 340, Santiago, Chile.
authors.forename: Rocío
authors.initials: R
authors.lastname: Artigas
authors.affiliation: Hematology-Oncology Department, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avda. Diagonal Paraguay 319, Santiago, Chile.
authors.forename: Lidia
authors.initials: L
authors.lastname: Medina
authors.affiliation: Hematology-Oncology Department, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avda. Diagonal Paraguay 319, Santiago, Chile. Electronic address: csanchez@med.puc.cl.
authors.forename: César
authors.initials: C
authors.lastname: Sánchez
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D000367:Age Factors; D001943:Breast Neoplasms / Q000097:blood / Q000150:complications*; D002677:Chile / Q000453:epidemiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000209:etiology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25OHD deficiency; Breast cancer; Vitamin D deficiency