Research2022-05-13T08:57:39-05:00

Review the Research

Get summaries of key research on vitamin D and COVID-19

Study Summaries

Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19 pandemic: A systematic review

Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19

Association of vitamin D deficiency with COVID-19 infection severity: Systematic review and meta-analysis

Association of vitamin D deficiency with COVID-19 infection severity: Systematic review and meta-analysis Take Home Message In this meta-analysis it is suggested that Vitamin D deficiency

Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis

Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis Take Home Message This meta-analysis suggested that there is a

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis. Take Home Message Vitamin D deficiency and obesity increases risk

Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis

Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis Take Home Message Vitamin D supplementation might be associated with improved clinical outcomes

Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies

Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies Take Home Message Vitamin D deficiency and

Vitamin D supplementation and COVID-19 treatment: A systematic review and meta-analysis.

Vitamin D supplementation and COVID-19 treatment: A systematic review and meta-analysis. Take Home Message This systematic review and meta-analysis of 5 studies found no significant difference

Short term, high-dose vitamin D supplementation for COVID-19 disease: a randomised, placebo-controlled, study (SHADE study).

In this 40 person randomized, placebo-controlled  study in India a greater proportion of vitamin D-deficient individuals with mildly symptomatic COVID-19 infections tested COVID-19 negative...

Vitamin D insufficiency in COVID-19 and influenza A, and critical illness survivors: a cross-sectional study

Take Home Message Vitamin D deficiency/insufficiency was present in majority of hospitalized patients with COVID-19 or influenza A and correlated with severity and persisted in critical

Impact of daily high dose oral vitamin D therapy on the inflammatory markers in patients with COVID 19 disease

Impact of daily high dose oral vitamin D therapy on the inflammatory markers in patients with COVID 19 disease. Take Home Message In a prospective open-label

Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach

Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach Take Home Message In this ecological study analyzing the

Detectable respiratory SARS-CoV-2 RNA is associated with low vitamin D levels and high social deprivation

Detectable respiratory SARS-CoV-2 RNA is associated with low vitamin D levels and high social deprivation Take Home Message In this group of 104 patients hospitalized in

Assessment of the Association of Vitamin D Level With SARS-CoV-2 Seropositivity Among Working-Age Adults

Assessment of the Association of Vitamin D Level With SARS-CoV-2 Seropositivity Among Working-Age Adults Take Home Message In this cohort study of 18,148 individuals whose vitamin

Association of vitamin D deficiency with COVID-19 infection severity: Systematic review and meta-analysis

Association of vitamin D deficiency with COVID-19 infection severity: Systematic review and meta-analysis Take Home Message In this meta-analysis it is suggested that Vitamin D deficiency

Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis

Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis Take Home Message This meta-analysis suggested that there is a

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis. Take Home Message Vitamin D deficiency and obesity increases risk

Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis

Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis Take Home Message Vitamin D supplementation might be associated with improved clinical outcomes

Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19 pandemic: A systematic review

Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19

Impact of daily high dose oral vitamin D therapy on the inflammatory markers in patients with COVID 19 disease

Impact of daily high dose oral vitamin D therapy on the inflammatory markers in patients with COVID 19 disease. Take Home Message In a prospective open-label

Vitamin D supplementation and COVID-19 treatment: A systematic review and meta-analysis.

Vitamin D supplementation and COVID-19 treatment: A systematic review and meta-analysis. Take Home Message This systematic review and meta-analysis of 5 studies found no significant difference

Vitamin D supplementation and outcomes in coronavirus disease 2019 (COVID-19) patients from the outbreak area of Lombardy, Italy

This study did not find a benefit associated with vitamin D supplementation in COVID-19 patients but did identify that vitamin D deficiency may be a risk factor for higher in-patient mortality.

Habitual use of vitamin D supplements and risk of coronavirus disease 2019 (COVID-19) infection: a prospective study in UK Biobank

In this prospective study, the self-reported use of vitamin D supplements was associated with a lower risk of COVID-19 infection, independent of lifestyle, socio-economic status, prevalent chronic diseases and circulating...

Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach

Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach Take Home Message In this ecological study analyzing the

Detectable respiratory SARS-CoV-2 RNA is associated with low vitamin D levels and high social deprivation

Detectable respiratory SARS-CoV-2 RNA is associated with low vitamin D levels and high social deprivation Take Home Message In this group of 104 patients hospitalized in

Assessment of the Association of Vitamin D Level With SARS-CoV-2 Seropositivity Among Working-Age Adults

Assessment of the Association of Vitamin D Level With SARS-CoV-2 Seropositivity Among Working-Age Adults Take Home Message In this cohort study of 18,148 individuals whose vitamin

Lack of association of baseline 25-hydroxyvitamin D levels with disease severity and mortality in Indian patients hospitalized for COVID-19

Lack of association of baseline 25-hydroxyvitamin D levels with disease severity and mortality in Indian patients hospitalized for COVID-19 Take Home Message In this cross-sectional, observational

Serum Calcium and Vitamin D levels: Correlation with severity of COVID-19 in hospitalized patients in Royal Hospital, Oman

Serum Calcium and Vitamin D levels: Correlation with severity of COVID-19 in hospitalized patients in Royal Hospital, Oman Take Home Message In this group of 445

Serum Levels of Vitamin C and Vitamin D in a Cohort of Critically Ill COVID-19 Patients of a North American Community Hospital Intensive Care Unit in May 2020: A Pilot Study.

Results of this pilot study support the need for further research to determine if vitamin C and vitamin D status should be assessed upon admission for COVID-19...

COVID-19 mortality increases with northerly latitude after adjustment for age suggesting a link with ultraviolet and vitamin D.

This study investigated the relationships between latitude, age of population, population density and pollution with COVID-19 mortality. The proportion of older people...

Prevalence of obesity and hypovitaminosis D in elderly with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

In elderly patients in Brazil testing positive for COVID-19 admitted to an ICU there was a high prevalence of obesity and low vitamin D levels. Whether or not the obesity and...

Vitamin D Supplementation Associated to Better Survival in Hospitalized Frail Elderly COVID-19 Patients: The GERIA-COVID Quasi-Experimental Study.

Large oral doses of vitamin D taken in the year prior to COVID-19 diagnosis were associated with less severe disease and better survival in frail elderly patients in France...

Mortality in an Italian nursing home during COVID-19 pandemic: correlation with gender, age, ADL, vitamin D supplementation, and limitations of the diagnostic tests

This observational study identified an inverse relationship between vitamin D treatment and COVID-19 related mortality: those receiving vitamin D supplementation...

The association between vitamin D levels and the clinical severity and inflammation markers in pediatric COVID-19 patients: single-center experience from a pandemic hospital

The association between vitamin D levels and the clinical severity and inflammation markers in pediatric COVID-19 patients: single-center experience from a pandemic hospital. Take Home Message

Ongoing Studies

Explore current trials being conducted around the world focused on vitamin D and COVID-19.

Title Status Conditions Interventions Location
Vitamin D Supplementation in Pregnant Women at Risk and COVID-19 Not yet recruiting • Pregnancy Complications
• Covid19		 • Vitamin D supplementation in pregnant women • Maria Jose Aguilar Cordero, Granada, Spain
Clinical Outcomes of High Dose Vitamin D Versus Standard Dose in COVID-19 Egyptian Patients Recruiting • Covid19
• Corona Virus Infection
• Cytokine Storm
• Vitamin D Deficiency		 • Teachers Hospital, Cairo, Egypt
Effect of Vitamin D on Hospitalized Adults With COVID-19 Infection Recruiting • Covid19 • Cholecalciferol
• Placebo		 • CHU Liège, Liège, Belgium
Baseline Vitamin D Deficiency and COVID-19 Disease Severity Recruiting • Vitamin D Deficiency
• Covid19		 • Vitamin D • Parkview Medical Center, Pueblo, Colorado, United States
Efficacy of Vitamin D Treatment in Mortality Reduction Due to COVID-19. Recruiting • SAR
• SARS Pneumonia		 • Vitamin D
• PLACEBO		 • Joaquín Durán Cantolla, Vitoria-Gasteiz, Alava, Spain
Vitamin D3 Supplementation to Prevent Respiratory Tract Infections Recruiting • Respiratory Tract Infections
• Covid19
• Flu Like Illness		 • Vitamin D supplementation • Cooper University Hospital, Camden, New Jersey, United States
Trial of Vitamin D to Reduce Risk and Severity of COVID-19 and Other Acute Respiratory Infections Active, not recruiting • Covid19
• Acute Respiratory Tract Infection		 • Vitamin D • Queen Mary University of London, London, County (optional), United Kingdom
Effect of Vitamin D on Morbidity and Mortality of the COVID-19 Recruiting • COVID-19 • Cholecalciferol • Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
Vitamin D and COVID-19 Trial Recruiting • COVID-19 • vitamin D
• Placebo		 • Brigham and Women’s Hospital, Boston, Massachusetts, United States
High Dose Vitamin-D Substitution in Patients With COVID-19: a Randomized Controlled, Multi Center Study Recruiting • Covid19
• Vitamin D Deficiency
• Corona Virus Infection
• ARDS
• Coronavirus
• SARS-CoV Infection		 • Single high dose vitamin D
• Placebo
• Treatment as usual vitamin D		 • Cantonal Hospital Aarau, Aarau, AG, Switzerland
• Cantonal Hospital Baselland Liestal, Liestal, BL, Switzerland
• Cantonal Hospital St. Gallen, Saint Gallen, SG, Switzerland
Vitamin D Status and Immune-inflammatory Status in Different UK Populations With COVID-19 Infection Not yet recruiting • Covid19 • no intervention • GSTT NHS Trust, London, United Kingdom
Efficacy of Vitamin D Treatment in Pediatric Patients Hospitalized by COVID-19 Recruiting • Covid19
• Vitamin D
• Children, Only		 • Cholecalciferol • Hospital Centro Medico Nacional Siglo XXI, Mexico City, Distrito Federal, Mexico
Tele-health Enabled Clinical Trial for COVID-19 Not yet recruiting • SARS-CoV Infection • Vitamin D3 or Placebo
• Doctella telehealth monitoring		 • Northwestern University, Chicago, Illinois, United States
N-terminal Pro B-type Natriuretic Peptide and Vitamin D Levels as Prognostic Markers in COVID-19 Pneumonia Recruiting • COVID19 Pneumonia • Pro BNP , Vitamin D • Kasr Alainy Cairo University, Cairo, Giza, Egypt
Prevention of COVID-19 With Oral Vitamin D Supplemental Therapy in Essential Healthcare Teams Recruiting • COVID-19 • Placebo
• Vitamin D		 • CHUM, Montreal, Quebec, Canada
• CHU Sainte-Justine (CHUSJ), Montreal, Quebec, Canada
Vitamin D Supplementation in the Prevention and Mitigation of COVID-19 Infection Recruiting • COVID-19
• Vitamin D Deficiency
• Respiratory Viral Infection		 • Daily Vitamin D3
• Daily placebo
• Bolus vitamin D3
• Bolus placebo		 • Medical University of South Carolina, Charleston, South Carolina, United States
The Effect of D3 on Selected Cytokines Involved in Cytokine Storm in the Covid-19 Uninfected Jordanian People Enrolling by invitation • Cytokine Storm • Vitamin D3 • Mahmoud S Abu-Samak, Amman, Jordan
Influence of Military Preventive Policy for reCruit Training on COVID-19 Seroconversion Recruiting • SARS-CoV Infection
• Vitamin D Deficiency
• Covid19
• Acute Respiratory Tract Infection		 • Vitamin D • Headingley and City campuses, Leeds Beckett University, Leeds, Yorkshire, United Kingdom
• Infantry Training Centre Catterick, Catterick Garrison, United Kingdom
Short Term, High Dose Vitamin D Supplementation for COVID-19 Active, not recruiting • COVID • Vit D • Deptt of Endocrinology, Chandigarh, India
Cholecalciferol to Improve the Outcomes of COVID-19 Patients Recruiting • COVID • Vitamin D
• Placebo		 • Hospital de Alta Complejidad en Red El Cruce, Florencio Varela, Buenos Aires, Argentina
Do Vitamin D Levels Really Correlated With Disease Severity in COVID-19 Patients? Enrolling by invitation • COVID • vitamin d • Bursa City Hospital, Bursa, Dogankoy, Turkey
Oral 25-hydroxyvitamin D3 and COVID-19 Recruiting • COVID 19 • Oral 25-Hydroxyvitamin D3 • Tehran University of Medical Sciences, Tehran, Iran, Islamic Republic of
Investigating the Role of Vitamin D in the Morbidity of COVID-19 Patients Not yet recruiting • COVID-19
• Vitamin D Deficiency		 • Tameside Hospital NHS Foundation Trust, Ashton-under-Lyne, Greater Manchester, United Kingdom
Vitamin D and COVID-19 Management Not yet recruiting • COVID-19 • Ddrops® products, 50,000 IU, Oral
• Vitamin D3
VITACOV: Vitamin D Polymorphisms and Severity of COVID-19 Infection Not yet recruiting • COVID-19 • Exposure • Cardiovascular Center at Universidade de Lisboa, Lisbon, Lisboa, Portugal
• Centro Hospitalar Universitário Lisboa Norte, Lisbon, Lisboa, Portugal
• Centro Hospitalar de São João, Oporto, Portugal
C0vid-19 and Vitamin D Supplementation: a Multicenter Randomized Controlled Trial of High Dose Versus Standard Dose Vitamin D3 in High-risk COVID-19 Patients (CoVitTrial) Recruiting • Coronavirus • cholecalciferol 200,000 IU
• cholecalciferol 50,000 IU		 • CHU Angers, Angers, France
• CHU Bordeaux, Bordeaux, France
• CH Le Mans, Le Mans, France
• CHU Lille, Lille, France
• CHU Limoges, Limoges, France
• CHU Nantes, Nantes, France
• CHU Nice, Nice, France
• CHU Saint Etienne, Saint Etienne, France
• CH Saumur, Saumur, France
• CHU Tours, Tours, France
Vitamin D on Prevention and Treatment of COVID-19 Not yet recruiting • Patients Infected With COVID-19 • Vitamin D • Universidad de Granada, Granada, Andalucia, Spain
• Medicine Faculty, Granada, Spain

The Importance of Vitamin D

What percentage of Americans are vitamin D deficient or insufficient?

The prevalence of vitamin D deficiency was found to be 28.9% and vitamin D insufficiency 41% in a subset of 26,010 US adults surveyed as part of the ongoing National Health and Nutrition Examination Survey (NHANES) 2001-2010.1 Vitamin D deficiency is a major health concern because it has been linked to depression, fatigue, muscle aches, increased risk of respiratory infections, autoimmune disorders, osteoporosis, osteomalacia, osteoarthritis, increased risk of infection and some cancers. Vitamin D insufficiency has been associated with reduced calcium absorption, decreased bone density, potential mild decrease of the blood calcium level, accelerated bone resorption, an increased risk of falls, and potentially fractures. Vitamin D deficiency and insufficiency can seriously affect a person’s quality of life.2,3,4

How is vitamin D different than other vitamins?

Unlike other vitamins, vitamin D is a prohormone. Dietary vitamin D first goes to the liver then the kidney converts it to its active form and distributes the active form throughout the body, which by definition makes vitamin D a “hormone-like” vitamin. Meaning it is synthesized and released from an endocrine organ, the kidneys. Vitamin D receptors are located throughout the body and explain why vitamin D is important for so many aspects of health.8

Who is more at risk of vitamin D deficiency or insufficiency?

In the U.S. seniors, South Asians, Hispanics and non-Hispanic Blacks are groups that have a higher prevalence of low vitamin D levels. Other situations that may lead to vitamin D deficiency or insufficiency include limited sun exposure, fat malabsorption conditions (such as celiac disease), and obesity. 5,6,7

What is the importance of vitamin D in the body?

Vitamin D was first known for its role in bone health and plays a key role in the metabolism, or cellular processes, of calcium and phosphorus, which are needed for bone integrity. Vitamin D has many other important functions too. It plays a key role in the immune system, oral health, muscle health and strength. It plays an important role in regulating gene transcription and promoting protein synthesis. All of these critical roles make vitamin D important for multiple aspects of human health. 9
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  1. Liu X, Baylin A, Levy PD. Vitamin D deficiency and insufficiency among US adults: prevalence, predictors and clinical implications. British Journal of Nutrition. 2018;119(8):928-936.
  2. Holick MF. The vitamin D deficiency pandemic: a forgotten hormone important for health. Public health reviews. 2010;32(1):267-283.
  3. Amrein K, Scherkl M, Hoffmann M, et al. Vitamin D deficiency 2.0: an update on the current status worldwide. European journal of clinical nutrition. 2020;74(11):1498-1513.
  4. MacLaughlin J, Holick MF. Aging decreases the capacity of human skin to produce vitamin D3. J Clin Invest. 1985;76(4):1536-1538.)
  5. Kweder H, Eidi H. Vitamin D deficiency in elderly: Risk factors and drugs impact on vitamin D status. Avicenna J Med. 2018;8(4):139-146. doi:10.4103/ajm.AJM_20_18). 3. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/#h5
  6. Emmanuel M. K. Awumey, Devashis A. Mitra, Bruce W. Hollis, Rajiv Kumar, Norman H. Bell, Vitamin D Metabolism Is Altered in Asian Indians in the Southern United States: A Clinical Research Center Study, The Journal of Clinical Endocrinology & Metabolism. 1998; 83(1): 169–173, https://doi.org/10.1210/jcem.83.1.4514
  7. Castro JP, Penckofer S. The role of vitamin D in the health of Hispanic adults with diabetes. Hisp Health Care Int. 2014;12(2):90-8. doi: 10.1891/1540-4153.12.2.90. PMID: 24871915.
  8. Sassi F, Tamone C, D’Amelio P. Vitamin D: nutrient, hormone, and immunomodulator. Nutrients. 2018;10(11):1656.
  9. Hewlings SJ, Medeiros DM. Nutrition: Real People, Real Choices. Pearson Prentice Hall; 2009.
  10. Elliott ME, Binkley NC, Carnes M, Zimmerman DR, Petersen K, Knapp K, Behlke JM, Ahmann N, Kieser MA. Fracture risks for women in long-term care: high prevalence of calcaneal osteoporosis and hypovitaminosis D. Pharmacotherapy. 2003; Jun;23(6):702-10.
  11. Nair R, Maseeh A. Vitamin D: The “sunshine” vitamin. J Pharmacol Pharmacother. 2012; Apr;3(2):118-26.
  12. Bilezikian JP, Bikle D, Hewison M, et al.Mechanisms in Endocrinology: Vitamin D and COVID-19. European Journal of Endocrinology. 2020;183(5):R133-r147.
  13. van Etten E, Mathieu C. Immunoregulation by 1,25-dihydroxyvitamin D3: basic concepts. The Journal of steroid biochemistry and molecular biology. 2005;97(1-2):93-101.
  14. Ginde AA, Mansbach JM, Camargo CA, Jr. Association between serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Archives of internal medicine. 2009;169(4):384-390.
  15. A Kempker, J., & S Martin, G. Vitamin D and sepsis: from associations to causal connections. Inflammation & Allergy-Drug Targets (Formerly Current Drug Targets-Inflammation & Allergy) (Discontinued). 2013; 12(4): 246-252.
  16. Zdrenghea, M. T., Makrinioti, H., Bagacean, C., Bush, A., Johnston, S. L., and Stanciu, L. A. Vitamin D modulation of innate immune responses to respiratory viral infections, Rev Med Virol. 2017; 27:e1909. doi: 10.1002/rmv.1909.
  17. Vetter V, Denizer G, Friedland LR, Krishnan J, Shapiro M. Understanding modern-day vaccines: what you need to know. Annals of medicine. 2018;50(2):110-120.
  18. Cannell JJ, Vieth R, Umhau JC, et al. Epidemic influenza and vitamin D. Epidemiology and infection. 2006;134(6):1129-1140.
  19. Martineau A R, Jolliffe D A, Hooper R L, Greenberg L, Aloia J F, Bergman P et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data BMJ. 2017; (356):i6583 doi:10.1136/bmj.i6583.
  20. Zabetakis I, Lordan R, Norton C, Tsoupras A. COVID-19: The Inflammation Link and the Role of Nutrition in Potential Mitigation. Nutrients. 2020 May 19;12(5):1466. doi: 10.3390/nu12051466. PMID: 32438620; PMCID: PMC7284818.
  21. Ross AC, Manson JE, Abrams SA, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. The Journal of clinical endocrinology and metabolism. 2011;96(1):53-58.
  22. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. Am J Clin Nutr. 2003;77(1):204-210.
  23. Rosen CJ, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu RA, et al. IOM committee members respond to Endocrine Society vitamin D guidelines. J Clin Endocrinol Metab. 2012;97:1146-52.
  24. MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2011;96:1911-30.
  25. Amrein K, Scherkl M, Hoffmann M, et al. Vitamin D deficiency 2.0: an update on the current status worldwide. European journal of clinical nutrition. 2020;74(11):1498-1513.

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