{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T02:37:35Z","timestamp":1784860655653,"version":"3.55.0"},"reference-count":40,"publisher":"BMJ","issue":"5","license":[{"start":{"date-parts":[[2023,5,25]],"date-time":"2023-05-25T00:00:00Z","timestamp":1684972800000},"content-version":"unspecified","delay-in-days":24,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","award":["447317"],"award-info":[{"award-number":["447317"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2023,4,26]]},"published-print":{"date-parts":[[2023,5]]},"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>In the COVID-19 pandemic, healthcare workers (HCWs) were at high risk of infection due to their exposure to COVID infections. HCWs were the backbone of our healthcare response to this pandemic; every HCW withdrawn or lost due to infection had a substantial impact on our capacity to deliver care. Primary prevention was a key approach to reduce infection. Vitamin D insufficiency is highly prevalent in Canadians and worldwide. Vitamin D supplementation has been shown to significantly decrease the risk of respiratory infections. Whether this risk reduction would apply to COVID-19 infections remained to be determined. This study aimed to determine the impact of high-dose vitamin D supplementation on incidence of laboratory-confirmed COVID-19 infection rate and severity in HCWs working in high COVID incidence areas.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and analysis<\/jats:title>\n                    <jats:p>\n                      PROTECT was a triple-blind, placebo-controlled, parallel-group multicentre trial of vitamin D supplementation in HCWs. Participants were randomly allocated in a 1:1 ratio in variable block size to intervention (one oral loading dose of 100\u2009000\u2009IU vitamin D\n                      <jats:sub>3<\/jats:sub>\n                      +10\u2009000\u2009IU weekly vitamin D\n                      <jats:sub>3<\/jats:sub>\n                      ) or control (identical placebo loading dose+weekly placebo). The primary outcome was the incidence of laboratory-confirmed COVID-19 infection, documented by RT-qPCR on salivary (or nasopharyngeal) specimens obtained for screening or diagnostic purposes, as well as self-obtained salivary specimens and COVID-19 seroconversion at endpoint. Secondary outcomes included disease severity; duration of COVID-19-related symptoms; COVID-19 seroconversion documented at endpoint; duration of work absenteeism; duration of unemployment support; and adverse health events. The trial was terminated prematurely, due to recruitment difficulty.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Ethics and dissemination<\/jats:title>\n                    <jats:p>This study involves human participants and was approved by the Research Ethics Board (REB) of the Centre hospitalier universitaire (CHU) Sainte-Justine serving as central committee for participating institutions (#MP-21-2021-3044). Participants provided written informed consent to participate in the study before taking part. Results are being disseminated to the medical community via national\/international conferences and publications in peer-reviewed journals.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"https:\/\/clinicaltrials.gov\/ct2\/show\/NCT04483635\">https:\/\/clinicaltrials.gov\/ct2\/show\/NCT04483635<\/jats:ext-link>\n                      .\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2022-064058","type":"journal-article","created":{"date-parts":[[2023,5,25]],"date-time":"2023-05-25T13:26:04Z","timestamp":1685021164000},"page":"e064058","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":6,"title":["Prevention of COVID-19 with oral vitamin D supplemental therapy in essential healthcare teams (PROTECT): protocol for a multicentre, triple-blind, randomised, placebo-controlled trial"],"prefix":"10.1136","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5096-0614","authenticated-orcid":false,"given":"Francine Monique","family":"Ducharme","sequence":"first","affiliation":[{"name":"Departments of Pediatrics and of Social and Preventive Medicine, Centre hospitalier universitaire (CHU) Sainte-Justine, University of Montreal, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C\u00e9cile","family":"Tremblay","sequence":"additional","affiliation":[{"name":"Microbiology and Infectious Disease, Centre Universitaire de sant\u00e9 de Montr\u00e9al (CHUM), University of Montreal, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shirin","family":"Golchi","sequence":"additional","affiliation":[{"name":"Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3962-2777","authenticated-orcid":false,"given":"Banafsheh","family":"Hosseini","sequence":"additional","affiliation":[{"name":"Clinical Research and Knowledge Transfer Unit on Childhood Asthma (CRUCA), Research Centre, CHU Sainte-Justine, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Longo","sequence":"additional","affiliation":[{"name":"Faculty of Pharmacy, University of Montreal, Montr\u00e9al, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John H","family":"White","sequence":"additional","affiliation":[{"name":"Physiology, McGill University, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Decio","family":"Coviello","sequence":"additional","affiliation":[{"name":"Applied Economics, HEC Montreal, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Quach","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Infectious Diseases & Immunology, CHU Sainte-Justine, University of Montreal, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Louis-Georges","family":"Ste-Marie","sequence":"additional","affiliation":[{"name":"Department of Medicine, Centre Universitaire de sant\u00e9 de Montr\u00e9al (CHUM), University of Montreal, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert W","family":"Platt","sequence":"additional","affiliation":[{"name":"Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Qu\u00e9bec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2023,5,25]]},"reference":[{"key":"2025121402404428000_13.5.e064058.1","doi-asserted-by":"crossref","first-page":"113","DOI":"10.46234\/ccdcw2020.032","article-title":"The Epidemiological characteristics of an outbreak of 2019 novel Coronavirus diseases (COVID-19) in China","volume":"2","year":"2020","journal-title":"China CDC Wkly"},{"key":"2025121402404428000_13.5.e064058.2","unstructured":"Gandy A . 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