Last Updated: August 16, 2022

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus. Since the virus was identified in 2019, it has spread and created a global pandemic. Vaccines are effective at reducing both the chance of contracting COVID-19 and the severity of the infection.

COVID-19 falls under theImmunity & Infectious Diseasecategory.

What is COVID-19?

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus. Since it was first described in December 2019, the disease has spread globally. The SARS-CoV-2 virus is primarily spread through respiratory droplets and aerosols, so risk is highest when people spend extended periods in close proximity with someone who is infected. There are many symptoms that COVID-19 and the flu have in common, but certain symptoms, such as a loss of smell or taste, can be a distinguishing factor.

What are the main signs and symptoms of COVID-19?

The symptoms of COVID-19 typically appear within 2–14 days of contracting the virus and can range from mild to severe. Symptoms include fever or chills, cough, shortness of breath, fatigue, muscle weakness, loss of smell or taste, headache, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea.[1]

How is COVID-19 diagnosed?

COVID-19 is diagnosed using a few different types of tests. Rapid tests look for viral particles and are available to the public, can be self-administered, and provide test results in less than an hour. Lab-based tests are more accurate, but results can take longer to come back. Serum tests can also be used to identify certain antibodies, which indicate if an individual has had a prior infection (or has been vaccinated). [2]

What are some of the main medical treatments for COVID-19?

Vaccines are effective for reducing the risk of contracting COVID-19, as well as the severity of illness should a vaccinated individual still contract the disease.[3]

Aside from supportive care (rest, hydration, over the counter medications), medical treatment isn’t necessarily recommended in people without risk factors for severe disease. In people who are at risk for severe disease, antiviral therapy (e.g., nirmatrelvir-ritonavir) is a first-line treatment.[4]

Have any supplements been studied for COVID-19?

Vitamin D has a wide range of effects on inflammation and the immune system. Although low serum vitamin D levels tend to be associated with increased risk of infection, severe illness, and death, studies that administer vitamin D to people prior to or after infection show mixed results.

Curcumin’s anti-inflammatory properties are well studied and could possibly reduce the severity of COVID-19.

How could diet affect COVID-19?

Diet-related health issues, like obesity, type 2 diabetes, and heart disease are major risk factors for severe disease and death in COVID-19.[5] As such, it’s important to have dietary habits that minimize the risk of these health conditions.

Like other respiratory infections, diet is also connected to the COVID-19 through immunity. Diets that are sufficient in energy, micronutrients, and macronutrients are important for maintaining a robust immune system, which will help reduce the risk and severity of COVID-19.[6] Flavonoids (plant compounds that can have antioxidant and immunomodulatory properties; found in especially high quantities in tea, chocolate, capers, and oregano)[7] may be a noteworthy phytonutrient for this purpose.[8]

Are there any other treatments for COVID-19?

The steps to mitigate the spread of COVID-19 are the same as other viral respiratory infections. This includes wearing masks to reduce the spread of respiratory droplets and aerosols while breathing, practicing social distancing when possible, and engaging in basic hygiene practices such as covering a cough and washing hands or using hand sanitizer.[9][10][11][12][13]

Although there isn’t much research on these practices for preventing the spread of COVID-19 specifically, these practices are effective for mitigating the spread of other respiratory viruses.

What causes COVID-19?

COVID-19 is caused by the SARS-CoV-2 virus. SARS-CoV-2 is primarily transmitted between people within 6 feet of each other through the air via respiratory droplets and aerosolized particles.[14] Severe disease or death is more common in people who are male, are of older age, have hypertension, diabetes, obesity, COPD, chronic liver or kidney diseases, cancer, or who are pregnant or have immunodeficiency or are taking immunosuppressive medications.[5]

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  1. ^CDCSymptoms of Coronavirus
  2. ^MedlinePlusCOVID-19 Testing
  3. ^CDCCOVID-19 Vaccines Work
  4. ^UpToDateCOVID-19: Outpatient evaluation and management of acute illness in adults
  5. ^Ya-Dong Gao, Mei Ding, Xiang Dong, Jin-Jin Zhang, Ahmet Kursat Azkur, Dilek Azkur, Hui Gan, Yuan-Li Sun, Wei Fu, Wei Li, Hui-Ling Liang, Yi-Yuan Cao, Qi Yan, Can Cao, Hong-Yu Gao, Marie-Charlotte Brüggen, Willem van de Veen, Milena Sokolowska, Mübeccel Akdis, Cezmi A AkdisRisk factors for severe and critically ill COVID-19 patients: A reviewAllergy.(2021 Feb)
  6. ^Michael GleesonImmunological aspects of sport nutritionImmunol Cell Biol.(2016 Feb)
  7. ^Alhamzah Hasan Waheed Janabi, Asghar Ali Kamboh, Muhammad Saeed, Lu Xiaoyu, Jannat BiBi, Fatima Majeed, Muhammad Naveed, Muhammad Jameel Mughal, Nazar Ali Korejo, Rubina Kamboh, Mahmoud Alagawany, Huixia LvFlavonoid-rich foods (FRF): A promising nutraceutical approach against lifespan-shortening diseasesIran J Basic Med Sci.(2020 Feb)
  8. ^Vaughan S Somerville, Andrea J Braakhuis, Will G HopkinsEffect of Flavonoids on Upper Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-AnalysisAdv Nutr.(2016 May 16)
  9. ^CDCYour Guide to Masks
  10. ^WHOCoronavirus disease (COVID-19): Masks
  11. ^Yanni Li, Mingming Liang, Liang Gao, Mubashir Ayaz Ahmed, John Patrick Uy, Ce Cheng, Qin Zhou, Chenyu SunFace masks to prevent transmission of COVID-19: A systematic review and meta-analysisAm J Infect Control.(2021 Jul)
  12. ^Jeremy Howard, Austin Huang, Zhiyuan Li, Zeynep Tufekci, Vladimir Zdimal, Helene-Mari van der Westhuizen, Arne von Delft, Amy Price, Lex Fridman, Lei-Han Tang, Viola Tang, Gregory L Watson, Christina E Bax, Reshama Shaikh, Frederik Questier, Danny Hernandez, Larry F Chu, Christina M Ramirez, Anne W RimoinAn evidence review of face masks against COVID-19Proc Natl Acad Sci U S A.(2021 Jan 26)
  13. ^Arjuna P De Silva, Madunil A Niriella, H Janaka de SilvaMasks in COVID-19: let's unmask the evidenceExpert Rev Respir Med.(2021 Mar)
  14. ^Eric A Meyerowitz, Aaron Richterman, Rajesh T Gandhi, Paul E SaxTransmission of SARS-CoV-2: A Review of Viral, Host, and Environmental FactorsAnn Intern Med.(2021 Jan)
  15. ^Juliana Arruda de Souza Monnerat, Pedro Ribeiro de Souza, Letícia Monteiro da Fonseca Cardoso, João Dario Mattos, Gabrielle de Souza Rocha, Renata Frauches MedeirosMicronutrients and bioactive compounds in the immunological pathways related to SARS-CoV-2 (adults and elderly)Eur J Nutr.(2021 Mar)
  16. ^Ana Heloneida de Araújo Morais, Jailane de Souza Aquino, Juliana Kelly da Silva-Maia, Sancha Helena de Lima Vale, Bruna Leal Lima Maciel, Thaís Sousa PassosNutritional status, diet and viral respiratory infections: perspectives for severe acute respiratory syndrome coronavirus 2Br J Nutr.(2021 Apr 28)
  17. ^Amin Gasmi, Torsak Tippairote, Pavan Kumar Mujawdiya, Massimiliano Peana, Alain Menzel, Maryam Dadar, Asma Gasmi Benahmed, Geir BjørklundMicronutrients as immunomodulatory tools for COVID-19 managementClin Immunol.(2020 Nov)
  18. ^Borchgrevink CP, Cha J, Kim SHand washing practices in a college town environmentJ Environ Health.(2013 Apr)
  19. ^Kampf G, Kramer AEpidemiologic background of hand hygiene and evaluation of the most important agents for scrubs and rubsClin Microbiol Rev.(2004 Oct)
  20. ^Arbogast JW, Moore-Schiltz L, Jarvis WR, Harpster-Hagen A, Hughes J, Parker AImpact of a Comprehensive Workplace Hand Hygiene Program on Employer Health Care Insurance Claims and Costs, Absenteeism, and Employee Perceptions and PracticesJ Occup Environ Med.(2016 Jun)
  21. ^Del Rio C, Malani PN2019 Novel Coronavirus-Important Information for CliniciansJAMA.(2020 Feb 5)
  22. ^Wong VW, Cowling BJ, Aiello AEHand hygiene and risk of influenza virus infections in the community: a systematic review and meta-analysisEpidemiol Infect.(2014 May)
  23. ^Teslya A, et alImpact of self-imposed prevention measures and short-term government intervention on mitigating and delaying a COVID-19 epidemicmedRxiv (PREPRINT).(2020-03-16)
  24. ^Merry AF, Miller TE, Findon G, Webster CS, Neff SPTouch contamination levels during anaesthetic procedures and their relationship to hand hygiene procedures: a clinical auditBr J Anaesth.(2001 Aug)
Examine Database References
  1. COVID-19 Severity - Shaun Sabico, Mushira A Enani, Eman Sheshah, Naji J Aljohani, Dara A Aldisi, Naif H Alotaibi, Naemah Alshingetti, Suliman Y Alomar, Abdullah M Alnaami, Osama E Amer, Syed D Hussain, Nasser M Al-DaghriEffects of a 2-Week 5000 IU versus 1000 IU Vitamin D3 Supplementation on Recovery of Symptoms in Patients with Mild to Moderate Covid-19: A Randomized Clinical TrialNutrients.(2021 Jun 24)
  2. COVID-19 Severity - Marta Entrenas Castillo, Luis Manuel Entrenas Costa, José Manuel Vaquero Barrios, Juan Francisco Alcalá Díaz, José López Miranda, Roger Bouillon, José Manuel Quesada Gomez"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.(2020 Oct)
  3. COVID-19 Severity - Igor H Murai, Alan L Fernandes, Lucas P Sales, Ana J Pinto, Karla F Goessler, Camila S C Duran, Carla B R Silva, André S Franco, Marina B Macedo, Henrique H H Dalmolin, Janaina Baggio, Guilherme G M Balbi, Bruna Z Reis, Leila Antonangelo, Valeria F Caparbo, Bruno Gualano, Rosa M R PereiraEffect of a Single High Dose of Vitamin D3 on Hospital Length of Stay in Patients With Moderate to Severe COVID-19: A Randomized Clinical TrialJAMA.(2021 Mar 16)
  4. COVID-19 Severity - Suma Thomas, Divyang Patel, Barbara Bittel, Kathy Wolski, Qiuqing Wang, Anirudh Kumar, Zachary J Il'Giovine, Reena Mehra, Carla McWilliams, Steve E Nissen, Milind Y DesaiEffect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction Among Ambulatory Patients With SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical TrialJAMA Netw Open.(2021 Feb 1)
  5. COVID-19 Severity - Saeidreza JamaliMoghadamSiahkali, Besharat Zarezade, Sogol Koolaji, SeyedAhmad SeyedAlinaghi, Abolfazl Zendehdel, Mohammad Tabarestani, Ehsan Sekhavati Moghadam, Ladan Abbasian, Seyed Ali Dehghan Manshadi, Mohamadreza Salehi, Malihe Hasannezhad, Sara Ghaderkhani, Mohsen Meidani, Faeze Salahshour, Fatemeh Jafari, Navid Manafi, Fereshteh GhiasvandSafety and effectiveness of high-dose vitamin C in patients with COVID-19: a randomized open-label clinical trialEur J Med Res.(2021 Feb 11)
  6. COVID-19 Severity - Hamed Valizadeh, Samaneh Abdolmohammadi-Vahid, Svetlana Danshina, Mehmet Ziya Gencer, Ali Ammari, Armin Sadeghi, Leila Roshangar, Saeed Aslani, Abdolreza Esmaeilzadeh, Mahnaz Ghaebi, Sepehr Valizadeh, Majid AhmadiNano-curcumin therapy, a promising method in modulating inflammatory cytokines in COVID-19 patientsInt Immunopharmacol.(2020 Dec)