Having a healthy immune system is important for COVID-19 recovery. You may consider complimenting COVID-19 treatments with foods that include vitamins A, C, and D, as well as carotenoids, zinc, and omega-3 fatty acids.


There’s an important relationship among your nutritional status, immune health, risk of infection, and ability to recover from illness (1, 2, 3).

Poor nutrition is associated with inflammation and oxidative stress, which compromise immune health. Both inflammation and oxidative stress are elevated when you have COVID-19 (1, 2).

The World Health Organization declared the novel coronavirus a pandemic in March 2020. The virus’s full name is severe acute respiratory syndrome coronavirus (SARS-CoV-2), and the illness it causes is called COVID-19 (4).

COVID-19 negatively affects nutritional status because it decreases appetite and may limit your access to nutritious foods during confinement, yet it simultaneously increases your body’s need for nutrients, such as vitamin D (3, 5, 6).

Diet and nutrition can help support your immune health if you have COVID-19, especially if you consume foods with antioxidant and anti-inflammatory properties (1, 2, 5, 6, 7).

It’s important to note that this is an emerging area of research. These foods won’t prevent you from contracting the novel coronavirus or cure the disease, but they have been shown to support immune health.

This article lists key nutrients, foods, and nutrition practices that may be beneficial for people who have COVID-19 or are recovering from it.

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Vitamin D is the most frequently discussed micronutrient among nutrition experts for the management of COVID-19 (5).

This fat-soluble vitamin and hormone exerts an anti-inflammatory effect by suppressing overactivity of the immune system, according to newer and older research (1, 5, 8, 9).

In the body, vitamin D acts on angiotensin converting enzyme 2 (ACE2), a protein receptor found in the lungs and fat tissue (1, 7).

The novel coronavirus binds to ACE2 at the beginning of an infection, potentially leading to acute respiratory distress syndrome and severe illness in people with COVID-19 (10).

However, vitamin D interacts with the ACE2 receptors, potentially preventing the virus from binding to them, and reducing complications associated with COVID-19 (1, 10, 11).

Vitamin D may also play a protective role and support healing of damaged tissues, primarily in the lungs (10).

Foods to eat

On average, people make approximately 80% of their vitamin D when their skin is exposed to sunlight (ultraviolet light) and get the remaining 20% from their diet (8).

As a result, taking vitamin D daily may be a good idea if you’re in confinement due to COVID-19 and have little sunlight exposure (5).

However, some medications may interact with vitamin D supplements — including blood thinners, which are common among people with COVID-19 as a result of the increased risk of blood clotting.

That’s why it’s best to speak with a healthcare professional before you start taking vitamin D supplements regularly.

Increasing your intake of vitamin D-rich foods while you have or are recovering from COVID-19 is a great way to reduce the risk of a vitamin D deficiency and potentially improve your immune response.

Here are seven foods rich in vitamin D, along with the amount of the vitamin each contains (12, 13, 14, 15, 16, 17, 18):

  • Cod liver oil: 170% of the Daily Value (DV) per 1 tablespoon (13.6 grams)
  • Herring: 27% of the DV per 100 grams
  • Egg yolk: 27% of the DV per 100 grams
  • Sardine: 24% of the DV per 100 grams
  • Canned light tuna: 34% of the DV per 100 grams
  • Salmon, wild-caught or farmed: 66% of the DV per 100 grams
  • Fortified orange juice: 25% of the DV per 100 grams

Wild mushrooms are a vegetarian source of vitamin D. Their levels vary depending on the type of light they were exposed to as they were growing, according to older research (19).

Summary

Vitamin D may help protect your lungs during novel coronavirus infection by disrupting viral attachment in your body. Several foods are rich in vitamin D, including cod liver oil, salmon, herring, and some wild mushrooms.

Carotenoids are antioxidants as well as pigments (red, green, yellow, and orange). They’re found in nature in some colorful algae, bacteria, fungi, plants, fruits, and vegetables, some of which you can include in your diet (20, 21).

Of the 700 carotenoids identified in nature, only about 30 have been found in the human body. One of these is vitamin A and its precursor, beta carotene (20, 22, 23).

Vitamin A is a fat-soluble antioxidant carotenoid. It has anti-inflammatory properties, and research has shown it may be beneficial for managing pneumonia and respiratory infections (1, 24, 25, 26).

In the case of COVID-19, studies indicate that vitamin A reduces inflammation and oxidative stress, enhances the immune response, and may decrease the severity of the disease (24, 25).

Researchers think it protects the ACE2 receptors, similarly to vitamin D, and may work on several other molecular targets to combat COVID-19 (24, 25).

Some people may develop vitamin A deficiency during infections such as COVID-19, and this may actually increase the severity of the disease. If this happens, you might need to take vitamin A supplements (25).

However, drug interactions are also possible if you’re taking vitamin A supplements, so make sure you speak with a healthcare professional before taking them.

Foods to eat

Dark green leafy vegetables and organ meats, particularly liver, are rich sources of vitamin A.

Here are eight foods rich in vitamin A, along with the % of the DV per 100 grams of each (27, 28, 29, 30, 31, 32, 33, 34):

  • Beef liver: 552% of the DV
  • Chicken liver: 327% of the DV
  • King mackerel: 24% of the DV
  • Goat cheese: 54% of the DV
  • Sweet potato, cooked: 87% of the DV
  • Collard greens: 28% of the DV
  • Carrots, raw: 93% of the DV
  • Baby spinach, raw: 31% of the DV
Summary

Vitamin A is a carotenoid that may help provide powerful protection against infections, including COVID-19. Food sources include liver, dark green leafy vegetables, and pigmented vegetables such as sweet potatoes and carrots.

Zinc deficiency has been associated with an increased risk of infections and poorer outcomes in those with COVID-19 (1, 35).

Zinc is regarded as one of the most important minerals. Research has shown that its antioxidant and anti-inflammatory properties may reduce the risk of heart disease, may support eye health, and are essential for immune health (36, 37, 38, 39).

In COVID-19, zinc may reduce the risk of getting a bacterial infection at the same time and decrease activity of the ACE2 receptors, which are targets of the novel coronavirus (40).

It also protects the health of the lung tissue and may be a therapeutic additional treatment for COVID-19. Studies on this are now underway (41, 42, 43, 44).

If you’ve received a diagnosis of zinc deficiency, your doctor may have recommended that you take zinc supplements. However, be careful not to take too much, because zinc is toxic in excess amounts. Stick to the dose your doctor recommends (45).

Foods to eat

Here are seven foods rich in zinc, along with the % of the DV per 100 grams of each (46, 47, 48, 49, 50, 51, 52):

  • Ground beef: 41% of the DV
  • Dark chocolate (70–85% cacao): 30% of the DV
  • Seafood oyster, canned: 73% of the DV
  • Cashew nuts: 53% of the DV
  • Hemp seeds: 90% of the DV
  • Pumpkin seeds: 71% of the DV
  • Lentils, sprouted, raw: 14% of the DV
Summary

Zinc is an essential mineral with anti-inflammatory properties that may benefit people with COVID-19. Rich food sources include ground beef, cashews, and hemp seeds.

Omega-3 polyunsaturated fats are a category of fatty acids shown to have anti-inflammatory health benefits, including for brain health, heart disease, and rheumatoid arthritis (1, 9, 53, 54).

These omega-3 fats, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may improve recovery in people with COVID-19 (55).

However, higher quality research in humans is needed before healthcare professionals may recommend taking it for this purpose.

Omega-3 fats reduce inflammation and the potential for the “cytokine storm” in COVID-19, which is hyperactivity of the immune system that causes negative symptoms.

They’re thought to do this by becoming part of cell membranes of various tissues throughout the body and preventing the production of pro-inflammatory compounds (56).

Another potential benefit of omega-3 fats in treating those with or recovering from COVID-19 is their role in improving mood, anxiety, and depression — all of which may be worsened by the novel coronavirus pandemic (57, 58).

Research is underway to determine the therapeutic role of omega-3 fats for COVID-19.

Foods to eat

Here are eight foods rich in omega-3 fatty acids, along with the amount of omega-3s found in each. Note that these contain different types of omega-3s (12, 15, 17, 29, 59, 60, 61, 62):

  • Chia seeds: 6 grams per 100 grams
  • Soybean, dry-roasted: 1.4 grams per 100 grams
  • Sardines, canned: 498 mg per 100 grams
  • Cod liver oil: 935 mg per tablespoon
  • King mackerel: 159 mg per 100 grams
  • Flaxseed: 23 grams per 100 grams
  • Walnuts: 9 grams per 100 grams
  • Salmon: 113 mg per 100 grams

As you may have noticed, many foods rich in omega-3 fats are also rich sources of vitamin D.

Summary

Omega-3 polyunsaturated fats are known for their anti-inflammatory health benefits and may help treat COVID-19. Foods rich in omega-3 fats include salmon, sardines, and chia seeds.

Vitamin C is an antioxidant vitamin that supports immune health in people of all ages (63).

Animal and human studies have found that vitamin C may reduce oxidative stress, improve endothelial function to guard against heart disease, and support recovery from the common cold (64, 65, 66).

Emerging research demonstrates that giving vitamin C to people with COVID-19 may support recovery and improvement during the disease course (44, 66, 67).

Vitamin C has a potential role in the prevention and management of pneumonia and bacterial infections such as sepsis, although some in the scientific community question its use (66, 67).

Preliminary evidence suggests that taking vitamin C may help those with COVID-19, but more studies in humans are needed (68).

Foods to eat

Here are eight foods naturally high in vitamin C, along with the % of the DV per 100 grams of each (69, 70, 71, 72, 73, 74, 75, 76):

  • Guava, raw: 253% of the DV
  • Acerola (West Indian cherry): 1,867% of the DV
  • Kiwi, raw: 103% of the DV
  • Cauliflower, raw: 54% of the DV
  • Canned tomatoes: 14% of the DV
  • Potato, with skin: 13% of the DV
  • Sweet pepper, red: 142% of the DV
  • Papaya, raw: 68% of the DV
Summary

Vitamin C is an antioxidant vitamin that supports immune health and is known to reduce the risk of pneumonia. This nutrient shows promise as a treatment for COVID-19, and more research is currently underway.

COVID-19 negatively affects nutritional status, and a healthy, functional immune system is paramount to reducing the risk of infection and supporting recovery.

Researchers are looking with great interest at vitamin D, carotenoids, vitamin A, zinc, omega-3 fatty acids, and vitamin C to determine their potential health benefits as complementary treatments for COVID-19.

There is currently no clinical evidence that a low histamine diet is beneficial to those with or recovering from COVID-19. More research in humans is needed.

Just one thing

Try this today: Pick out a new fruit or vegetable to try from the grocery store. Eating a variety of foods with anti-inflammatory properties supports immune health.

Check out these eight Caribbean cultural foods to learn more.

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