10 Nutrients Essential For A Healthy Immune System

The way to good health is through nutrition and exercise.  I firmly believe this.  It is the foundation for Pink Ribbon Runner.  And, of course, I am not alone in that belief.  Many great scientists and physicians also believed this.  They have studied it. And they have wrote volumes about it. 

Let food be thy medicine.

– Hippocrates –

“Nutritional Interventions”

When I came across a recent article in the Journal of Medical Virology, I got very excited.  This scientific review paper said the first step of treating viral disease is to review the patient’s nutritional status.  Over half of the journal article discussed the science of nutrition in preventing and treating viruses.  The first heading, Nutritional Interventions, gives me goosebumps!    

The rest of the paper discussed medical treatments, which are equally important, but not as exciting, in my eyes.  I am not a physician, so I won’t be touching on any medical treatments.  I will discuss nutrition in layman’s terms though. 

As I dove deeper into the science journals to explore these Nutritional Interventions, my excitement grew.  The result is this blog post about 10 nutrients essential to keep your immune system healthy.  All of these nutrients can be found in healthy foods that are easy to find in the grocery store.  How absolutely brilliant is that!   

**Note that the daily recommendations given below are for the average healthy adult.  Upper limits should never be approached without advice from your doctor.  Nutrient data is from consumerlab.com.**

Vitamin A

  • Alternate names: Retinol, Retinoic Acid
  • Daily Recommendation: 900 mcg
  • Upper Limit: 3000 mcg
  • Sources: eggs, fish, leafy green vegetables, liver, apricots, cantaloupe, carrot, pumpkin, squash, sweet potato

Vitamin A primes your body’s defenses against invading disease-causing agents.  It is nicknamed the “anti-infective” vitamin.  This nutrient has reduced incidences of disease in measles, malaria and HIV. 

Vitamin A is also important for your body to function well.  It is especially important for healthy eyes, heart, lungs, kidneys and other organs.

Nutrients essential for a healthy immune system

Vitamin B2                                                                   

  • Alternate name: riboflavin
  • Daily Recommendation: 1.3 mg
  • Upper Limit: Not Determined
  • Sources: eggs, fish, nuts, molasses, lima beans, navy beans, asparagus, artichoke, mushrooms, almonds, avocado, cayenne, currents, kelp, cruciferous vegetables, fortified cereals

Riboflavin is an antioxidant nutrient. It is essential for the healthy functioning of every cell in the body.  As an antioxidant, it helps protect cells against oxidative stress and free radical damage. 

If you are lacking vitamin B2 in your diet, you will feel tired, sluggish and weak. You may also get colds and flus more easily.

The doctor of the future will no longer treat the human frame with drugs, but rather will cure and prevent disease with nutrition.” 

– Thomas Edison –

Vitamin B3

  • Alternate names: niacin, nicotinamide, niacinamide, nicotinic acid
  • Daily Recommendation: 16 mg
  • Upper Limit: 35 mg
  • Sources: fish, poultry, beef, peas, sunflower seeds, mushrooms, avocado, peanuts, kidney beans, whole grains, sweet bell peppers, broccoli, asparagus, coffee

Vitamin B3 has been shown to protect the heart, lungs and other organs during severe bacterial infections.  It helps by reducing oxidative stress and increases the body’s ability to destroy harmful bacteria.   

Vitamin B6

  • Alternate name: pyridoxine
  • Daily Recommendation: 1.7 mg
  • Upper Limit:  100 mg
  • Sources: poultry, fish, beans, dark leafy greens, chickpeas, banana, papaya, oranges, cantaloupe

Vitamin B6 is a coenzyme.  Its job is to help over 100 other enzymes in the body do their job properly. Such a helpful vitamin!  It is involved in metabolism of most macronutrients, such as protein, fats and carbohydrates. 

If you are lacking vitamin B6, your body can’t make antibodies.  This vitamin is also important in the proper function of some immune cells, called T-cells, that help fight viruses.

We must pay greater attention to keeping our bodies and minds healthy and able to heal. Yet we are making it difficult for our defenses to work. We allow things to be sold that should not be called food. Many have no nutritive value and lead to obesity, salt imbalance, and allergies.

– David Suzuki –

Vitamin C

  • Alternate names: ascorbic acid, ascorbate
  • Daily Recommendation: 90 mg
  • Upper Limit: 2000 mg
  • Sources: citrus fruits, cruciferous vegetables, guava, kiwi, papaya, snow peas, strawberries, sweet bell peppers

The link between vitamin C and immunity is not new.  We have known for decades that vitamin C supports our immune system. 

Vitamin C can help ward off infections, shorten the duration of colds and flus, and help us repair damaged tissues in our body.  It seems especially helpful when viruses affect the respiratory tract, such as for colds and flus. 

Vitamin D3

  • Alternate name: Cholecalciferol
  • Daily Recommendation: 800 IU
  • Upper Limit: 4000 IU
  • Sources: sunshine, fish, egg yolk, liver, fortified milks and cereals

Vitamin D is so important for health that I wrote an entire article about it here.  It is nicknamed the “sunshine” vitamin because we can make our own by sitting out in the sun. 

Vitamin D is important for proper growth and function of our immune cells.  People with low vitamin D levels experience more colds and flus.  Without the sunshine vitamin, people may also experience more severe symptoms or develop complications, such as bronchitis and pneumonia. 

“An apple a day keeps the doctor away.”

– Benjamin Franklin –

Vitamin E

  • Alternate names: tocopherol, tocotrienol
  • Daily Recommendation: 15 mg
  • Upper Limit: 1000 mg
  • Sources: fish, wheat germ, sunflower seeds, almonds, peanuts, avocado, sweet bell peppers, mango, dark leafy green vegetables, squash

Vitamin E is another antioxidant vitamin.  It helps to protect our heart and lungs from free radical damage caused from inflammation. 

Low levels of vitamin E have been shown to help RNA viruses become more aggressive and invade healthy cells. 

Omega 3 Fatty Acids

  • Daily Recommendation: 200 – 500 mg
  • Upper Limit: 4000 mg
  • Sources: fatty fish (mackerel, salmon, trout, sardine), shrimp, oysters, seaweed, chia seed, hemp seed, flax seed, walnuts, edamame, kidney beans, soybean oil

Omega 3 fatty acids are necessary for the body to deal with inflammation and respond to infections.  They help damaged cells repair their outer membranes.  And these valuable fats help us make more white blood cells to fight invading viruses.

“Today, more than 95% of all chronic disease is caused by food choice, toxic food ingredients, nutritional deficiencies and lack of physical exercise.”

– Mike Adams –


  • Daily Recommendation: 55 mcg
  • Upper Limit: 400 mcg
  • Sources: Fish, eggs, poultry, brazil nuts, cashews, beans, mushrooms, oatmeal, brown rice, spinach, lentils, bananas, sunflower seeds

Selenium is a mineral, not a vitamin.  But it does work with Vitamin E, in particular, to help prevent free radical damage in the body.  This mineral is also important to help T-cells and macrophages gobble up harmful bacteria and viruses.

Low levels of selenium can help viruses mutate and replicate.  Studies have shown that normally weak viruses can be much more aggressive without enough selenium hanging around. 


  • Daily Recommendation: 11 mg
  • Upper Limit:  40 mg
  • Sources: beef, chicken, shellfish, eggs, whole grains, fortified cereals, pumpkin seeds, beans, nuts, potatoes, dark chocolate

Zinc is another mineral that is essential for a healthy immune system.  Zinc lozenges have become popular to help reduce the severity and duration of the common cold.  There are some studies to back this up. 

Zinc helps immune cells mature and function properly.  This mineral also has some antioxidant effects.  And it is an important component in many enzymes involved in the inflammatory response. 

“If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have the safest way to health.”

– Hippocrates –

See a Doctor if you are Sick

Foods as prevention or therapy isn’t foolproof.  Immunity is a brilliantly complicated biological system.  There are many factors and pathways involved.  And there are lots of places where things can go wrong.  Nutrition is just one component, albeit a very powerful one.

Healthy foods are adjunctive therapy.  This means that eating well, along with other medical interventions, can help you fight disease.  It does not mean that you can just treat yourself with food, without help from your physician.  You still need to see a doctor if you are not well.

Adjunctive therapy is any accessory treatment used in combination to enhance primary treatment.The Free Dictionary

It Doesn’t Have to be Complicated

Was that a lot to take in?  I am a science geek, so I love how these nutrients work in the body.  I love that the foods we eat are digested and broken down to supply us with such powerful nutrients.  And I love how these nutrients are used by our cells to protect our cells, fight disease-causing agents and heal us.  It really is a marvel of nature; a beautiful and grand design.

Perhaps you don’t find all this as exciting and invigorating as I do?  So, I have summarized all this information into a list of the top 10 foods to eat to help protect yourself against viruses. 

And as you can see from the list below, this isn’t new information.  But it is a reminder to make healthy choices when you are planning your meals. 

“The easiest diet is, you know, eat vegetables, eat fresh food. Just a really sensible healthy diet like you read about all the time.”

– Drew Carey –

Overall Top 10 Foods Containing Immune-Boosting Nutrients

  1. Fish
  2. Eggs
  3. Dark leafy greens
  4. Cruciferous vegetables
  5. Sweet bell peppers
  6. Whole grains
  7. Nuts & Seeds
  8. Beans & Lentils
  9. Avocado
  10. Mushrooms

Eat well. And please stay healthy! 


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    1. There are lots of reasons people can become ill. But what we eat is a big one. It is important to eat a healthy diet.

  1. Needed to read this! I’ve been feeling so blah and gross from the food I’ve been eating recently. It’s so important now more than ever to be boosting up our immune systems. Going to definitely incorporate some of these foods into my meals tomorrow.

    1. It is amazing how healthy foods make you feel energized and good. Junkie and comfort foods are only a temporary fix. Heavy foods full of salt, sugar and unhealthy fats rob us of energy and make us want even more comfort food to help with the blah. It is a vicious cycle. I am glad you are breaking free of this and on the road to eating healthy. You will feel so much better.

  2. I normally am good about consuming and making sure to get all my nutrients, but since the start of the lockdown, I have been a lot more concerned with other issues, so it hasn’t been prioritized. I needed this reminder today, especially of Zinc. Thank you for including the list of top 10 nutrient dense foods.

    1. You aren’t alone! Many of us have been reaching for comfort foods to combat the stress. My weakness and go-to comfort food is potato chips. I have been eating too much of this junk too. But I did cut up a giant plate of fresh veggies yesterday. I noticed it was all gone today. Wonderful. I will cut up more today.

  3. Your post is a great reminder that we really “are what we eat!” It is so important we fuel our bodies with things from the earth. Thank you for sharing!

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