Effect of a test-and-treat approach to vitamin D supplementation on risk of all cause acute respiratory tract infection and covid-19: phase 3 randomised controlled trial (CORONAVIT).

Objective: To determine the effect of population level implementation of a test-and-treat approach to correction of suboptimal vitamin D status (25-hydroxyvitamin D (25(OH)D) <75 nmol/L) on risk of all cause acute respiratory tract infection and covid 19.
Design: Phase 3 open label randomised controlled trial.
Setting: United Kingdom.
Participants: 6200 people aged ≥16 years who were not taking vitamin D supplements at baseline.
Interventions: Offer of a postal finger prick test of blood 25(OH)D concentration with provision of a six month supply of lower dose vitamin D (800 IU/day, n=1550) or higher dose vitamin D (3200 IU/day, n=1550) to those with blood 25(OH)D concentration <75 nmol/L, compared with no offer of testing or supplementation (n=3100). Follow-up was for six months.
Main Outcome Measures: The primary outcome was the proportion of participants with at least one swab test or doctor confirmed acute respiratory tract infection of any cause. A secondary outcome was the proportion of participants with swab test confirmed covid-19. Logistic regression was used to calculate odds ratios and associated 95% confidence intervals. The primary analysis was conducted by intention to treat.
Results: Of 3100 participants offered a vitamin D test, 2958 (95.4%) accepted and 2674 (86.3%) had 25(OH)D concentrations <75 nmol/L and received vitamin D supplements (n=1328 lower dose, n=1346 higher dose). Compared with 136/2949 (4.6%) participants in the no offer group, at least one acute respiratory tract infection of any cause occurred in 87/1515 (5.7%) in the lower dose group (odds ratio 1.26, 95% confidence interval 0.96 to 1.66) and 76/1515 (5.0%) in the higher dose group (1.09, 0.82 to 1.46). Compared with 78/2949 (2.6%) participants in the no offer group, 55/1515 (3.6%) developed covid-19 in the lower dose group (1.39, 0.98 to 1.97) and 45/1515 (3.0%) in the higher dose group (1.13, 0.78 to 1.63).
Conclusions: Among people aged 16 years and older with a high baseline prevalence of suboptimal vitamin D status, implementation of a population level test-and-treat approach to vitamin D supplementation was not associated with a reduction in risk of all cause acute respiratory tract infection or covid-19.
Trial Registration: ClinicalTrials.gov NCT04579640.
Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: funding from Barts Charity, Pharma Nord, Fischer Family Foundation, DSM Nutritional Products, Exilarch’s Foundation, Karl R Pfleger Foundation, AIM Foundation, Synergy Biologics, Cytoplan, UK National Institute for Health and Care Research Clinical Research Network, the HDR UK BREATHE Hub, the UK Research and Innovation Industrial Strategy Challenge Fund, Thornton & Ross, Warburtons, Matthew Isaacs (a philanthropist without financial interests constituting a potential conflict), and Hyphens Pharma. JS receives payments from Reach for news stories written about recruitment to, and findings of, the COVIDENCE UK study. RAL is a member of the Welsh government COVID-19 Technical Advisory Group. AS and JN declare research infrastructure support to the University of Edinburgh from the Industrial Strategy Challenge Fund (ISCF) and Health Data Research United Kingdom (HDR UK). AS is a member of the Scottish government chief medical officer’s COVID-19 Advisory Group and its Standing Committee on Pandemics. He is also a member of the UK Government’s NERVTAG’s Risk Stratification Subgroup. ARM declares receiving funding in the past three years to support vitamin D research from several companies that manufacture or sell vitamin D supplements: Pharma Nord, DSM Nutritional Products, Thornton & Ross, and Hyphens Pharma. ARM also declares support for attending meetings from companies that manufacture or sell vitamin D supplements (Pharma Nord and Abiogen Pharma); receipt of a consultancy fee from DSM Nutritional Products; receipt of a speaker fee from the Linus Pauling Institute; participation on data and safety monitoring boards for the VITALITY trial (Vitamin D for Adolescents with HIV to reduce musculoskeletal morbidity and immunopathology, Pan African Clinical Trials Registry ref PACTR20200989766029) and the Trial of Vitamin D and Zinc Supplementation for Improving Treatment Outcomes Among COVID-19 Patients in India (ClinicalTrials.gov ref NCT04641195); unpaid work as a programme committee member for the Vitamin D Workshop; and receipt of vitamin D capsules for clinical trial use from Pharma Nord, Synergy Biologics, and Cytoplan.
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