Using a low-dose ultraviolet-B lighting solution during working hours: An explorative investigation towards the effectivity in maintaining healthy vitamin D levels

PLOS ONE RESEARCH ARTICLE Using a low-dose ultraviolet-B lighting solution during working hours: An explorative investigation towards the effectivity in maintaining healthy vitamin D levels Laura M. Huiberts ID1, Karin C. H. J. Smolders1, Bianca M. I. van der Zande2, Rémy C. Broersma2, Yvonne A. W. de Kort ID1* a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands, 2 Signify Research, Eindhoven, the Netherlands * Abstract OPEN ACCESS Citation: Huiberts LM, Smolders KCHJ, van der Zande BMI, Broersma RC, de Kort YAW (2023) Using a low-dose ultraviolet-B lighting solution during working hours: An explorative investigation towards the effectivity in maintaining healthy vitamin D levels. PLoS ONE 18(3): e0283176. https://doi.org/10.1371/journal.pone.0283176 Editor: Walid Kamal Abdelbasset, Prince Sattam Bin Abdulaziz University, College of Applied Medical Sciences, SAUDI ARABIA Received: December 9, 2021 Accepted: July 23, 2022 Published: March 31, 2023 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0283176 Copyright: © 2023 Huiberts et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Data cannot be shared publicly because of the informed consent Objective This study examined whether daily safe, low-dose ultraviolet-B (UVB) exposure using a home-based lighting solution could maintain healthy serum 25(OH)D during winter. Methods Twenty-eight (12 male, 16 female) daytime (~9:00 to 17:00) indoor workers (mean age = 42.46; SD = 14.23) participated in this study and were allocated to one of the two study conditions. During an 8-week period, fourteen participants received extra UVB exposure (max 0.3 standard erythema dose (SED) daily), while fourteen participants in the control group did not receive extra UVB exposure. Daily questionnaires were used to measure UVB exposure time, exposed body surface area (BSA), and time spent outside in daylight. Serum 25(OH) D, vitamin D related food intake, and secondary parameters (i.e., subjective fatigue, sleep timing and quality) were investigated at baseline, Week 4, and Week 8. Results Serum 25(OH)D significantly declined over the 8-week study period in both groups. The combination of using a low-dose UVB exposure, a small BSA, and a lower-than-expected amount of exposure hours likely resulted in an insufficient UVB dose to significantly improve serum 25(OH)D. Changes in serum 25(OH)D over time did not significantly correlate with changes in secondary parameters of sleep and fatigue. Conclusion The received low-dose UVB exposure in this study did not significantly change serum 25 (OH)D during the winter period. Future research could explore whether a longer lasting exposure period and/or using different exposure positions of the device (maximizing exposed skin surface) yields more promising results for improving serum 25(OH)D. PLOS ONE | https://doi.org/10.1371/journal.pone.0283176 March 31, 2023 1 / 18 PLOS ONE form stating that data will be only available to others in an encrypted and password protected institutional online data repository. Data are available upon request via the OSF project page through which requests can be sent to the authors (https://osf.io/qnk26/) or via the institutional Ethics Committee (contact via ). Funding: This research was funded by Signify, Eindhoven, the Netherlands. Funders had a role in the study design, data collection (only light measurements), and preparation of the manuscript. Funders had no role in data collection from participants, data analysis, and decision to publish. Competing interests: The authors have declared that no competing interests exist. Effectivity of using a low-dose UVB lighting solution to maintain healthy vitamin D levels Trial registration Trial registration: https://www.isrctn.com/ISRCTN47902923. 1. Introduction Vitamin D insufficiency (< 30 ng/ml; <75 nmol/L) affects more than 70% of the general population worldwide [1] and has been associated with health consequences such as osteoporosis, cancer, and autoimmune disorders in the long term [2,3], and increased susceptibility to viral and bacterial infections in the short term [4]. The main route of vitamin D synthesis is via ultraviolet-B (UVB) exposure. However, due to indoor lifestyles (~70–90% of our time [5–7]) and most of the sunlight’s UVB radiation being absorbed by the ozone layer at higher latitudes [8], many people miss out on the benefits of UVB exposure, even in summer season [9]. Moreover, food sources alone do not contain adequate vitamin D concentrations to ensure sufficient (> 75 nmol/L) serum vitamin D (25(OH)D) levels [10,11]. Recent studies also revealed a potentially important role of daily vitamin D synthesis in facilitating mental wellbeing and sleep [12], due to its role in serotonin and melatonin regulation [13,14]. Given the high prevalence of vitamin D insufficiency, increasing Vitamin D status in the general population is expected to positively influence feelings of wellbeing and sleep quality [12]. Therefore, ensuring sufficient vitamin D levels may not only decrease health care costs but also economic costs by increasing productivity at work and preventing sick leave [15]. Daily supplementation with vitamin D can be a good solution to reach sufficient serum 25 (OH)D. However, adherence to a vitamin D supplementation scheme is very important to sustain sufficient levels, which may not be easy for everyone. Moreover, vitamin D synthesis via UVB exposure is expected to be more efficient in raising serum 25(OH)D compared to supplement intake [16,17]. Last, UVB exposure also exclusively leads to the synthesis of different vitamin D metabolites in the skin which all have unique contributions to health and wellbeing, such as anti-inflammatory effects [18]. Because of the above-mentioned benefits, receiving low-dose artificial UVB exposure in winter seems an unobtrusive solution to improve serum 25(OH)D. Previous controlled and uncontrolled studies using UV light sources to improve serum 25(OH)D revealed that exposure to relatively low doses of UVB may be adequate for maintaining healthy 25(OH)D levels throughout winter [17,19–25]. For example, a previous dose-response study showed that a cumulative standard erythema dose (SED) of 8 delivered over a 16-week period already proved to be sufficient to sustain summer 25(OH)D levels in winter compared to receiving no extra UVB ex (...truncated)