title: Increased vitamin D-binding protein and decreased free 25(OH)D in obese women of reproductive age.
abstract: OBJECTIVE
  Obese subjects have lower circulating 25-hydroxyvitamin D (25(OH)D) than normal-weight subjects. Knowledge is scarce regarding differences in vitamin D-binding protein (DBP), free 25(OH)D, and intake of vitamin D between normal-weight and obese subjects. The purpose of this study was to examine intake and vitamin D status in obese compared with normal-weight women.
  
  
  METHODS
  Between September 2009 and October 2011, 43 obese and 43 normal-weight women, 22-45 years of age, mean BMI of 39.1 ± 4.6 and 21.6 ± 1.8 kg/m(2), respectively, were recruited in the western Sweden region (latitude 57°N). Blood samples, data regarding diet, and sun exposure were collected.
  
  
  RESULTS
  DBP concentrations were 320 ± 121 and 266 ± 104 μg/mL (P = 0.02) in obese and normal-weight women, respectively. Calculated free 25(OH)D was 13.3 ± 5.5 (obese) and 23.7 ± 10.7 (normal-weight) (P < 0.001). The obese women had a 20.1 nmol/L lower mean 25(HO)D concentration compared to normal-weight women (P < 0.001). 56 % of obese women and 12 % of normal-weight women had 25(OH)D concentrations ≤50 nmol/L. There was no statistically significant difference in total vitamin D intake between the groups. 39 % of the women had a total vitamin D intake <7.5 μg/day, the current national recommendation for vitamin D in Sweden.
  
  
  CONCLUSIONS
  Obese women had higher DBP concentrations compared with normal-weight women and lower free 25(OH)D. The obese women were more likely to have 25(OH)D concentrations that could be considered suboptimal. Vitamin D intake was generally low in normal-weight and obese women of childbearing age.
authors.affiliation: Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, P.O. Box 432, 405 30, Göteborg, Sweden, therese.karlsson@neuro.gu.se.
authors.forename: Therese
authors.initials: T
authors.lastname: Karlsson
authors.forename: Amra
authors.initials: A
authors.lastname: Osmancevic
authors.forename: Nina
authors.initials: N
authors.lastname: Jansson
authors.forename: Lena
authors.initials: L
authors.lastname: Hulthén
authors.forename: Agneta
authors.initials: A
authors.lastname: Holmäng
authors.forename: Ingrid
authors.initials: I
authors.lastname: Larsson
mesh_terms: D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D003430:Cross-Sectional Studies; D004032:Diet; D019587:Dietary Supplements; D002149:Energy Intake; D005260:Female; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000097:blood*; D013472:Sunlight; D011795:Surveys and Questionnaires; D013548:Sweden; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014809:Vitamin D-Binding Protein / Q000097:blood*; D055815:Young Adult
chemical_list: D014809:Vitamin D-Binding Protein; D014807:Vitamin D; C104450:25-hydroxyvitamin D