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.

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]

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]

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]

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.

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]

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.

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]