The proposed pilot study uses a prospective, longitudinal, randomized design with repeated measures to address vitamin D sufficiency in Active Duty (AD), retiree, beneficiary, and Department of Army civilian populations. It is important and necessary to conduct this study with adult humans, military personnel in particular, to determine acceptability and feasibility of this phototherapy kiosk as an addition to existing Warfighter resources to promote health and resilience. Anticipating 20% attrition, approximately 120 volunteers will be recruited from Madigan Army Medical Center and Joint Base Lewis-McChord (JBLM), a large joint base in the Pacific Northwest, where over 25,000 Soldiers and Airmen train every day and regional beneficiaries number \~98,000. Recruiting efforts will attempt to capture a representative sample of the population including genders, diverse ethnicities, and a range of age (18-70 years) and body mass index, who have no contraindication for Ultraviolet (UV) B exposure or oral vitamin D supplementation. Using a computer-generated block design, volunteers will be randomized to one of two treatment groups; 1) oral vitamin D supplementation, or 2) standing phototherapy kiosk (SPK) with UVB exposure, for a 10 week period.
Group 1- Supplement: A Madigan Army Medical Center (MAMC) Research Pharmacist will dispense a 10-week supply of the vitamin D3 600 International Units (IU) oral supplement to subjects assigned to this group one time. The Project Coordinator will work with the pharmacist to coordinate pick-up of supplement bottles for subjects or optimal in-person dispensing times.
Group 2 - SPK: The Project Coordinator will oversee the phototherapy treatment. Spectrum isolation modules in the kiosk will deliver the UVB dose under supervised conditions over a 2-5 minute interval based on the Fitzpatrick skin type category with the subject wearing minimal or no clothing, preferably no more than a bathing suit and protective eye-wear. The experience in the SPK is designed to be comfortable.
We will enroll all eligible adult volunteers regardless of their baseline 25(OH)D level; it is important to show there is no potential for harm from phototherapy, even if the baseline 25(OH)D level is above 30 ng/mL. We also must learn the trajectory of vitamin D absorption and availability over a 3-4 month period in order to make evidence-based therapeutic recommendations. It is not possible to blind the subjects or research team to the group assignment. Serum levels of 25(OH)D, calcium, and parathyroid hormone will be drawn at baseline (T0), and immediately following the intervention at 10 weeks (T6); at 14 weeks (T8), 25(OH) D will be drawn to document sustainment of treatment effect. A survey will be completed at T1 to capture relevant demographic, medical history, sun exposure, travel, daily activities, and dietary data. Active duty participants will also report the number of days on profile for the previous three months, at T1 and T6. A survey regarding Device Usability will be administered upon kiosk protocol completion. We will analyze data using repeated measures analysis of variance adjusting for significant covariates such as 25(OH)D level at baseline. Logistic regression analyses will be used to predict outcomes and explain the interrelationships among variables, i.e. age, gender, body fat, BMI, ethnicity, and sun exposure relationship to 25(OH)D serum levels.
Outcomes:
1. Serum 25(OH)D level. This primary outcome will be crucial to establishing whether the device, a standing phototherapy kiosk (SPK), is equivalent to oral vitamin D3 supplementation which is currently the standard of care prescribed by licensed providers to address vitamin D insufficiency/deficiency. We will establish a baseline 25(OH)D level for both study arms.
2. Change in serum 25(OH)D at 10 weeks to reflect adequacy of SPK and supplement treatment.
3. Change in serum 25(OH)D at 14 weeks will evaluate sustainment of the post-SPK treatment level.
4. Device acceptability by Device Usability Scale. To properly evaluate the outcome of acceptability of this demonstration project involving two arms, one an SPK and the other an oral vitamin D supplement, the research team will administer the Device Usability Scale upon study completion at 14 weeks.
5. Device feasibility will be assessed by meticulously tracking of the number of potential participants screened, the number of enrolled subjects, and attrition from each arm. Reasons for attrition will be documented following a discussion with the subject, if possible.
