title: Co-Administration of Soy Isoflavones and Vitamin D in Management of Irritable Bowel Disease.
abstract: OBJECTIVE
  The substantial characteristics of Irritable Bowel Syndrome (IBS) are associated with estrogens in women. Both soy isoflavones and vitamin D can modulate estrogen receptors in the colonic smooth muscles. The aim of this study was to investigate the effects of soy isoflavones, vitamin D and their probable interactions in women with IBS.
  
  
  METHODS
  In a factorial blinded randomized clinical trial, 100 women with IBS (age:18-75yr, were randomly assigned in 4 arms to receive either placebo of vitamin D and placebo of soy isoflavones (P+P), or placebo of vitamin D and soy isoflavones (P+S), or vitamin D and placebo of soy isoflavones (D+P), or vitamin D and soy isoflavones (D+S) for 6 weeks. Dosage of soy isoflavone was 2 capsules of 20 mg soy isoflavones per day, and dosage of vitamin D was one pearl of 50'000 IU biweekly. The clinical outcomes were IBS symptoms severity scores (IBS-SSS), disease- specific quality of life (IBS-QOL) and total score (IBS-TS) that evaluated at weeks 0, 6, and 10, and compared to each other.
  
  
  RESULTS
  IBS-TS improved significantly in both S+P and D+P groups (p- value = 0.004, 0.015). The interaction effect of soy isoflavones and vitamin D on IBS-TS was significant (p<0.05). The interaction effect of soy isoflavones with vitamin D and the main effect of vitamin D on IBS-SSS were not statistically significant, whereas IBS-SSS decreased significantly in S+P and D+P groups (p-value = 0.001, 0.047 respectively).
  
  
  CONCLUSIONS
  Our results indicate that co-administration of soy isoflavones with vitamin D did not improve the IBS- SSS and IBS- QOL; however, it improved the IBS-TS.
  
  
  BACKGROUND
  Clinical Trials.gov NCT02026518.
authors.affiliation: Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Mahsa
authors.identifier: http://orcid.org/0000-0001-7825-9483
authors.initials: M
authors.lastname: Jalili
authors.affiliation: National Nutrition and Food Technology Research Institute, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Azita
authors.initials: A
authors.lastname: Hekmatdoost
authors.affiliation: Digestive disease research center (DDRC), Digestive Disease Research Institute, Tehran, Iran.
authors.forename: Homayoon
authors.initials: H
authors.lastname: Vahedi
authors.affiliation: Liver and pancreatic biliary research group, Digestive Disease Research Institute, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Poustchi
authors.affiliation: Students' Research Committee, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Behnam
authors.initials: B
authors.lastname: Khademi
authors.affiliation: Students' Research Committee, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Saadi
authors.affiliation: Students' Research Committee, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Zemestani
authors.affiliation: Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Janani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy* / Q000473:pathology; D007529:Isoflavones / Q000008:administration & dosage*; D008875:Middle Aged; D015990:Placebo Effect; D011788:Quality of Life; D012720:Severity of Illness Index; D013025:Glycine max / Q000737:chemistry* / Q000378:metabolism; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014807:Vitamin D / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D007529:Isoflavones; D014807:Vitamin D