As parents, we all know the struggle of dealing with constant cycles of sickness when our kids are young. It’s exhausting, often leaving us sleep-deprived and catching more colds ourselves. But while we can’t avoid every illness, we can take steps to strengthen our children’s immune systems—and it starts with what we put on their plates.
And with more things that arise with healthcare in our lives, we are taught that there is a medical intervention - take a pill, have a procedure, or whatever it may be. We now know enough to know that yes indeed there are medicines to take to blunt the effects of a cold (although there are few you can give to your youngest kiddos) and nutrients we know help build immunity. But these things are only marginally helpful, and we should be thinking about our immune systems and our kids' immune systems more holistically, because our immune systems are built on more than a handful of nutrients from pills. There are a whole host of factors from sleep, exercise, stress and food that impact the functioning of our immune systems.
A strong immune system not only prevents frequent colds, but protects our gut health, keeps our energy levels up, and keeps inflammation in check thereby preventing chronic illnesses and promoting longevity.
Everything mentioned above is critical to a properly functioning immune system, but since I’m a pediatric dietitian, I’m going to focus on what I know best, and that’s food. The components in food are powerful and can deeply affect the functioning of our immune system. I’m certainly for supplements, as needed, to be supplemental as the name implies filling in gaps that may be there or for increased needs due to malabsorption, increased requirements, and deficiencies. But I think our mindsets as parents should be to aim to get nutrients from food and fill in small gaps with supplements. So in this blog post, I am going to focus on where to get immune boosting nutrients in food.
Connection between diet and immunity
How the Immune System Works
The immune system is like your body’s personal army, protecting you from germs like viruses, bacteria, and fungi that can make you sick. The first line of defense includes your skin, mucus (like in your nose), and stomach acid. They act like barriers, stopping germs from getting inside your body. And the second line of defense includes white blood cells, which attack and destroy harmful germs. If the same germ tries to invade again, your body remembers it and fights it off faster—this is called immunity.
Nutrients are Important, but so is Diet
We know certain nutrients, like Vitamin C, zinc and more are important (and we will get to specific nutrients below), but the diet as a whole matters. Your immune system needs so much more than a few key nutrients. Other things that contribute to poor health include an over abundance of sugar and micronutrient deficiencies. Plus there are many other compounds in food that we also know contribute to a good immune system - gingerol in ginger, lycopene in tomatoes, as well as other carotenoids and flavonoids found in a variety of fruits and vegetables. This is why I prefer focusing on eating a wider variety of foods to make up a balanced diet, especially in kids.Then there is less room to fill up on the foods we don’t need and more likely our kids will get the nutrients they need without becoming deficient.
Key Nutrients and Foods That Contain Them
Vitamin C
What role does vitamin C play in our immune system?
Vitamin C stimulates white blood cells and helps our bodies fight infections. It also helps prevent cell damage and maintains the integrity of our skin and mucus membranes, so in part works with both our first and second lines of defense. Studies on taking vitamin C supplementally have been mixed, but perhaps taking vitamin C or consuming enough vitamin C would shorten the duration and severity of colds you catch. You can read more in a previous blog post, Can Vitamin C Prevent Colds?
What foods can I feed my kids to boost vitamin C intake?
Vitamin C is found in most fruits and vegetables, so the best strategy is to give your kids fruits and/or vegetables at every meal. But some are particularly high in vitamin C. Those include citrus fruits, bell peppers, strawberries, kiwi. And it’s great in the fall, because peppers are still in season, so my kids will snack on them or I will include them in many dishes. Then moving into winter, citrus is everywhere. I peel tons of mandarins and set them out for my kids. We are currently waiting for our favorite Cara Cara oranges to appear in the store. If you have never tried one, keep your eyes peeled for them come January!
Vitamin D
What role does vitamin D play in our immune system?
Vitamin D is also involved in our first line of defense against pathogens by enhancing the production of antimicrobial peptides, as well as influencing how immune cells work for our second line of defense. Read up more in a previous blog post, How Vitamin D Boosts Immunity.
What foods can I feed my kids to boost vitamin D intake?
Unlike vitamin C, which is readily available to those eating fruits and vegetables, vitamin D is a little harder to consume. You can find vitamin D in fatty fish, like salmon and trout or fortified foods, such as, dairy products, and orange juice, and even in certain eggs, mushrooms, and beef liver. But really the best way to get vitamin D is from sunlight. Our bodies convert the form coming from the sun into the form our bodies can use. But if you live in a climate with little cun parts of the year, you may not be making much vitamin D. So this is one nutrient that people are often deficient in, and if you are this is one you may want to take in supplement form.
Protein
What role does protein play in our immune system?
Protein is the foundation for many of our immune system functions. It provides building blocks for immune cells and antibodies, as well as repairing tissues and supporting gut health. A balanced diet with adequate protein ensures the immune system has the resources it needs to defend the body effectively.
What foods can I feed my kids to boost protein intake?
Most kids get adequate protein, but something to keep in mind is making sure to give protein-rich foods throughout the day and to give kids a variety of protein sources. Good sources of protein include meats, beans, eggs, dairy products, nuts and tofu.
Zinc
What role does zinc play in our immune system?
Zinc produces and activates immune cells, it boosts antibody production, it strengthens the skin barrier and speeds up tissue repair. All of these activities benefit our immune system, making zinc a very important nutrient during cold and flu season. And there is some evidence to support taking zinc to shorten the duration of a cold, as well as possibly decrease the severity. More on this in the previous blog post, Zinc and Kid’s Immunity.
What foods can I feed my kids to boost zinc intake?
The best sources of zinc come from nuts, seeds, meats, whole grains and shellfish. You can read up more on zinc and foods from the NIH Fact Sheet. I try to give my kids oatmeal, whole grains and shrimp on a regular basis, plus many days I will sprinkle pumpkin seeds, sesame seeds, or hemp seeds into dishes knowing I am giving them a natural zinc boost.
Probiotics
What role do probiotics play in our immune system?
Probiotics' primary role is to promote a healthy balance of gut bacteria. This may not seem related to the immune system, but it definitely is! Did you know 70% of the immune system is on the gut? Probiotics help by strengthening the gut barrier, activating immune cells to fight infections, regulating inflammatory responses and outcompeting harmful bacteria that cause infections.
What foods can I feed my kids to boost probiotic intake?
Probiotics are found in foods like yogurt, kefir, and fermented foods like kimchi, sauerkraut and kombucha. You can also now find probiotics added to other dairy foods like cottage cheese and sour cream, as well as in dairy alternatives.
Antioxidants
What role do antioxidants play in our immune system?
Antioxidants are crucial for the immune system because they protect the body from damage caused by free radicals, which are unstable molecules produced during normal processes like metabolism or in response to stress, pollution, and infection. Antioxidants shield our immune cells from oxidative stress caused by free radicals, as well as neutralizing the free radicals and supporting the repair of damaged tissues and cells.
What foods can I feed my kids to boost antioxidant intake?
There are many types of antioxidants. Some are vitamins and minerals, like vitamin C, vitamin E, zinc and selenium that are needed for many functions in our body and are available to be taken as a supplement.
Others, mostly fall into the category of phytochemicals, which include carotenoids, flavonoids, tannins and phenolic acids. These compounds work in synergy with other compounds in food to elicit their antioxidant effects. This makes these nutrients harder to isolate and provide synthetically. Eating whole, colorful plant-based foods is the best way to ensure you get the full range of phytochemicals and their health benefits.
Some great sources of phytochemical specific antioxidants include:
- Carotenoids, like beta-carotene, lycopene, and lutein are found in carrots, sweet potatoes, tomatoes, spinach, grapefruit, cabbage, watermelon and broccoli.
- Flavonoids are found in berries, onions, legumes and soy.
- Tannins may be something you associate with red wine, but they are also found in berries, chocolate, legumes, as well as some nuts and grains.
- Phenolic acids are found in coffee, grains, berries, and apples.
The immune system is a complex, resilient defense system—and food plays a critical role in keeping it strong. While supplements can help fill occasional gaps, building a robust immune system starts with a balanced diet rich in whole foods. By focusing on variety and ensuring your child gets plenty of colorful fruits and vegetables, proteins, and probiotic-rich foods, you’re giving their immune system the tools it needs to thrive.
Beyond nutrients, it's also important to promote healthy lifestyle habits like good sleep, regular physical activity, and stress management. Together, these strategies can reduce the frequency and severity of illnesses, making life a little less chaotic and a lot more enjoyable.
Remember: Feeding kids can be challenging, but every bite of nutritious food is a step toward raising resilient, healthy children.
Further Reading:
1.This factsheet by the NIH breaks down the efficacy and safety of the nutrients mentioned, plus more: https://ods.od.nih.gov/factsheets/ImmuneFunction-Consumer/