Mathematical analysis of Córdoba calcifediol trial suggests strong role for Vitamin D in reducing ICU admissions of hospitalized COVID-19 patients
Irwin Jungreis, Manolis Kellis
doi:10.1101/2020.11.08.20222638
A randomized controlled trial of calcifediol (25-hydroxyvitamin D 3 ) as a treatment for hospitalized COVID-19 patients in Córdoba, Spain, found that the treatment was associated with reduced ICU admissions with very large effect size and high statistical significance, but the study has had limited impact because it had only 76 patients and imperfect blinding, and did not measure vitamin D levels pre-and post-treatment or adjust for several comorbidities. Here we reanalyze the reported results of the study using rigorous and well established statistical techniques, and find that the randomization, large effect size, and high statistical significance address many of these concerns. We show that random assignment of patients to treatment and control groups is highly unlikely to distribute comorbidities or other prognostic indicators sufficiently unevenly to account for the large effect size. We also show that imperfect blinding would need to have had an implausibly large effect to account for the reported results. Finally, comparison with two additional randomized clinical trials of vitamin D supplementation for COVID-19 in India and Brazil indicates that early intervention and rapid absorption may be crucial for the observed benefits of vitamin D. We conclude that the Córdoba study provides sufficient evidence to warrant immediate, well-designed pivotal clinical trials of early calcifediol administration in a broader cohort of inpatients and outpatients with COVID-19.
References
Aatsinki, Elkhwanky, Kummu, Karpale, Buler et al., Fasting-Induced Transcription Factors Repress Vitamin D Bioactivation, a Mechanism for Vitamin D Deficiency in Diabetes, Diabetes
Amrein, Sourij, Wagner, Holl, Pieber et al., Short-term effects of high-dose oral vitamin D3 in critically ill vitamin D deficient patients: a randomized, double-blind, placebo-controlled pilot study, Critical Care,
doi:10.1186/cc10120.
Baqui, Bica, Marra, Ercole, Van Der Schaar, Ethnic and regional variations in hospital mortality from COVID-19 in Brazil: a cross-sectional observational study, The Lancet Global Health,
doi:10.1016/s2214-109x(20)30285-0.
Basu, Vitamin D supplement calcifediol could reduce death risk in Covid patients, Spanish study says, Theprint
Benskin, A Basic Review of the Preliminary Evidence That COVID-19 Risk and Severity Is Increased in Vitamin D Deficiency, Frontiers in Public Health
Bishop, Rein in the four horsemen of irreproducibility, Nature
Castillo, Costa, Vaquero Barrios, Alcalá Díaz, Miranda et al., Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study, J. Steroid Biochem. Mol. Biol
Chen, Sun, Vitamin D deficiency and essential hypertension, J. Am. Soc. Hypertens
Chen, Zhou, Dong, Qu, Gong et al., Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study, Lancet
Cornfield, Haenszel, Hammond, Lilienfeld, Shimkin et al., Smoking and lung cancer: recent evidence and a discussion of some questions, J. Natl. Cancer Inst
Evans, Lippman, Shining Light on the COVID-19 Pandemic: A Vitamin D Receptor Checkpoint in Defense of Unregulated Wound Healing, Cell Metab,
doi:10.1016/j.cmet.2020.09.007.
Garvin, Alvarez, Miller, Prates, Walker et al., A mechanistic model and therapeutic interventions for COVID-19 involving a RAS-mediated bradykinin storm, Elife,
doi:10.7554/eLife.59177.
Greenhouse, Commentary: Cornfield, epidemiology and causality, Int. J. Epidemiol
Ilie, Stefanescu, Smith, The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality, Aging Clin. Exp. Res
Jetter, Egli, Dawson-Hughes, Staehelin, Stoecklin et al., Pharmacokinetics of oral vitamin D(3) and calcifediol, Bone
Jungreis, Kellis Mathematical analysis of calcifediol for COVID-19 11
Karahan, Katkat, Impact of Serum 25 (OH) Vitamin D Level on Mortality in Patients with COVID-19 in Turkey, J. Nutr. Health Aging
Laird, Rhodes, Kenny, Vitamin D and Inflammation: Potential Implications for Severity of Covid-19, Ir. Med. J
Macaya, Paeres, Valls, Fernández-Ortiz, Del Castillo et al., Interaction between age and vitamin D deficiency in severe COVID-19 infection, Nutr. Hosp,
doi:10.20960/nh.03193.
Murai, Fernandes, Sales, Pinto, Goessler et al., Effect of Vitamin D3 Supplementation vs Placebo on Hospital Length of Stay in Patients with Severe COVID-19: A Multicenter, Double-blind, Randomized Controlled Trial,
doi:10.1101/2020.11.16.20232397v1.full-text
Negre, Azpitarte, Del Arenal Barrios, Herrero, None, Calcifediol soft capsules
Pearce, Cheetham, Diagnosis and management of vitamin D deficiency, BMJ
Putzu, Belletti, Cassina, Clivio, Monti et al., Vitamin D and outcomes in adult critically ill patients. A systematic review and meta-analysis of randomized trials, J. Crit. Care
Pérez, Puente Nieto, Martínez-Cuazitl, Montelongo Mercado, Tort, Deficiency of vitamin D is a risk factor of mortality in patients with COVID-19, Rev. Sanid. Milit
Quesada-Gomez, Entrenas-Castillo, Bouillon, Vitamin D receptor stimulation to reduce acute respiratory distress syndrome (ARDS) in patients with coronavirus SARS-CoV-2 infections: Revised Ms SBMB 2020_166, J. Steroid Biochem. Mol. Biol
Radujkovic, Hippchen, Tiwari-Heckler, Dreher, Boxberger et al., Vitamin D Deficiency and Outcome of COVID-19 Patients, Nutrients,
doi:10.3390/nu12092757.
Rastogi, Bhansali, Khare, Suri, Yaddanapudi et al., Short term, high-dose vitamin D supplementation for COVID-19 disease: a randomised, placebo-controlled, study (SHADE study), Postgraduate Medical Journal,
doi:10.1136/postgradmedj-2020-139065.
Rhodes, Dunstan, Laird, Subramanian, Kenny, COVID-19 mortality increases with northerly latitude after adjustment for age suggesting a link with ultraviolet and vitamin D
Singer, Blaser, Berger, Alhazzani, Calder et al., ESPEN guideline on clinical nutrition in the intensive care unit, Clin. Nutr
Skversky, Kumar, Abramowitz, Kaskel, Melamed, Association of Glucocorticoid Use and Low 25-Hydroxyvitamin D Levels: Results from the National Health and Nutrition Examination Survey (NHANES): 2001-2006, J. Clin. Endocrinol. Metab
Tan, Ho, Kalimuddin, Cherng, Teh et al., Cohort study to evaluate effect of vitamin D, magnesium, and vitamin B12 in combination on severe outcome progression in older patients with coronavirus (COVID-19), Nutrition
Wilf, Vitamin D Can Likely End the COVID-19 Pandemic: A Probabilistic Analysis of Recent Findings
Wu, Chen, Cai, Xia, Zhou et al., Risk Factors Associated With Acute Respiratory Distress Syndrome and Death in Patients With Coronavirus Disease 2019 Pneumonia in Wuhan, China, JAMA Intern. Med
Yang, Yu, Xu, Shu, Xia et al., Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-centered, retrospective, observational study, Lancet Respir Med
Zhou, Yang, Chi, Dong, Lv et al., Comorbidities and the risk of severe or fatal outcomes associated with coronavirus disease 2019: A systematic review and meta-analysis, Int. J. Infect. Dis
Zhou, Yu, Du, Fan, Liu et al., Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study, Lancet
Zhu, Ochalek, Kaufmann, Jones, Deluca, CYP2R1 is a major, but not exclusive, contributor to 25-hydroxyvitamin D production in vivo, Proceedings of the National Academy of Sciences,
doi:10.1073/pnas.1315006110.
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'Prevention & Health. (2020) bmjnph–2020–000110.',
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'Herrera , Interaction between age and vitamin D deficiency in severe '
'COVID-19 infection, Nutr. Hosp. (2020). '
'https://doi.org/10.20960/nh.03193.',
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'Patients, Nutrients. 12 (2020). https://doi.org/10.3390/nu12092757.',
'DOI': '10.3390/nu12092757'},
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'doi-asserted-by': 'crossref',
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'Mercado , A.R. Tort , Deficiency of vitamin D is a risk factor of '
'mortality in patients with COVID-19, Rev. Sanid. Milit. 74 (2020). '
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'B.K. Amos , A.E. Mast , A. Justice , B. Aronow , D. Jacobson , A '
'mechanistic model and therapeutic interventions for COVID-19 involving a '
'RAS-mediated bradykinin storm, Elife. 9 (2020). '
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'DOI': '10.7554/eLife.59177'},
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'(accessed 13 September, 2020).'},
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'Probabilistic Analysis of Recent Findings, Rootclaim. (2020). '
'https://blog.rootclaim.com/vitamin-d-can-likely-end-the-covid-19-pandemic/ '
'(accessed September 24, 2020).'},
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'Sachdeva , G.D. Puri , P. Malhotra , Short term, high-dose vitamin D '
'supplementation for COVID-19 disease: a randomised, placebo-controlled, '
'study (SHADE study), Postgraduate Medical Journal. (2020) '
'ostgradmedj–2020. https://doi.org/10.1136/postgradmedj-2020-139065.',
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'C.S.C. Duran , C.B.R. Silva , A.S. Franco , M.B. Macedo , H.H.H. '
'Dalmolin , Others, Effect of Vitamin D3 Supplementation vs Placebo on '
'Hospital Length of Stay in Patients with Severe COVID-19: A Multicenter, '
'Double-blind, Randomized Controlled Trial, medRxiv. (2020). '
'https://www.medrxiv.org/content/10.1101/2020.11.16.20232397v1.full-text.',
'DOI': '10.1101/2020.11.16.20232397'},
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'first-page': '435',
'DOI': '10.1038/d41586-019-01307-2',
'article-title': 'Rein in the four horsemen of irreproducibility',
'volume': '568',
'year': '2019',
'journal-title': 'Nature'},
{ 'key': '2020122406550514000_2020.11.08.20222638v2.27',
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'article-title': 'Smoking and lung cancer: recent evidence and a discussion of some '
'questions',
'volume': '22',
'year': '1959',
'journal-title': 'J. Natl. Cancer Inst'},
{ 'key': '2020122406550514000_2020.11.08.20222638v2.29',
'unstructured': 'J.M.S. Negre , I.O. Azpitarte , P. Del Arenal Barrios , G.H. Herrero , '
'Calcifediol soft capsules, 10525018, 2020. '
'https://patentimages.storage.googleapis.com/9a/b3/95/c4d287dbc6caa4/US10525018.pdf '
'(accessed December 3, 2020).'},
{ 'key': '2020122406550514000_2020.11.08.20222638v2.30',
'first-page': 'R104',
'article-title': 'Short-term effects of high-dose oral vitamin D3 in critically ill '
'vitamin D deficient patients',
'volume': '15',
'year': '2011',
'journal-title': 'a randomized, double-blind, placebo-controlled pilot study, Critical '
'Care'},
{ 'key': '2020122406550514000_2020.11.08.20222638v2.31',
'doi-asserted-by': 'publisher',
'DOI': '10.1016/j.bone.2013.10.014'},
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'DOI': '10.1016/S0140-6736(20)30566-3'},
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'DOI': '10.1210/jc.2011-1600'},
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'unstructured': 'NIH COVID-19 Treatment Guidelines, (2020). '
'https://www.covid19treatmentguidelines.nih.gov/immune-based-therapy/immunomodulators/corticosteroids/ '
'(accessed December 4, 2020).'},
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'DOI': '10.1073/pnas.1315006110'},
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'Garcia , M.P. Kieny , R. Malekzadeh , S. Murthy , M.-P. Preziosi , '
'Others, Repurposed antiviral drugs for COVID-19; interim WHO SOLIDARITY '
'trial results, medRxiv. (2020). '
'https://www.medrxiv.org/content/10.1101/2020.10.15.20209817v1.abstract.'},
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'first-page': '109',
'article-title': 'Vitamin D and outcomes in adult critically ill patients',
'volume': '38',
'year': '2017',
'journal-title': 'A systematic review and meta-analysis of randomized trials, J. Crit. '
'Care'}],
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