title: Improving Vitamin D Status and Related Health in Young Women: The Safe-D study - Part B.
abstract: BACKGROUND
  Vitamin D deficiency is highly prevalent and associated with increased risk of a number of chronic health conditions including cardiovascular disease, poor bone and muscle health, poor mental health, infection, and diabetes. Vitamin D deficiency affects millions of Australians, potentially causing considerable suffering, economic loss, and mortality.
  
  
  OBJECTIVE
  To measure the effectiveness of a (1) mobile-based app (behavioral) and (2) pharmacological intervention to increase circulating 25-hydroxyvitamin D (serum 25 OHD) levels and health outcomes over 4 months of intervention compared with usual care in a cohort of young women with suboptimal serum 25 OHD levels (25-75 nmol/L).
  
  
  METHODS
  Participants with 25 OHD levels 25 to 75 nmol/L are invited to participate in this study. Participants are randomized to one of three groups in 1:1:1 ratio: a mobile phone-based application, vitamin D supplementation (1000 IU/day), and a control group. Data collection points are at baseline, 4, and 12 months post baseline with the major endpoints being at 4 months. A wide-range of information is collected from participants throughout the course of this study. General health, behavioral and demographic information, medications, smoking, alcohol and other substance use, health risk factors, nutrition, eating patterns and disorders, and mental health data are sourced from self-administered, Web-based surveys. Clinical data include anthropometric measurements, a silicone skin cast of the hand, cutaneous melanin density, bone mineral density, and body composition scans obtained through site visits. Main analyses will be conducted in two ways on an intention-to-treat (ITT) basis using the last observation carried forward approach as an imputation for missing data, and on a per protocol basis to compare the intervention arms against the control group at 4 and 12 months.
  
  
  RESULTS
  Publication of trial results is anticipated in 2017.
  
  
  CONCLUSIONS
  The study will allow assessment of the effects of a mobile-based app behavioral intervention and vitamin D supplementation on vitamin D status and will evaluate the effects of improving vitamin D levels on several health outcomes.
authors.affiliation: Department of Medicine, Royal Melbourne Hospital, University of Melbourne, VIC, Australia.
authors.forename: Marjan
authors.identifier: http://orcid.org/0000-0002-3737-508X
authors.initials: M
authors.lastname: Tabesh
authors.forename: Suzanne Marie
authors.identifier: http://orcid.org/0000-0002-6869-311X
authors.initials: SM
authors.lastname: Garland
authors.forename: Alexandra
authors.identifier: http://orcid.org/0000-0003-1032-0457
authors.initials: A
authors.lastname: Gorelik
authors.forename: Alison
authors.initials: A
authors.lastname: Nankervis
authors.forename: Skye
authors.initials: S
authors.lastname: Maclean
authors.forename: Emma Teressa
authors.identifier: http://orcid.org/0000-0002-3046-7694
authors.initials: ET
authors.lastname: Callegari
authors.forename: Shanton
authors.identifier: http://orcid.org/0000-0002-2163-3910
authors.initials: S
authors.lastname: Chang
authors.forename: Kayla
authors.identifier: http://orcid.org/0000-0003-0816-8986
authors.initials: K
authors.lastname: Heffernan
authors.forename: John Dennis
authors.identifier: http://orcid.org/0000-0003-2431-7902
authors.initials: JD
authors.lastname: Wark
keywords: Safe-D study, behavioral intervention; app; eHealth; health outcomes; intervention; vitamin D; vitamin D supplementation; young women