Supporting Kids' Immunity
Published by the Emerson Ecologics Medical Education Team
Sniffles and tummy aches are a normal part of being a kid. Pediatricians say toddlers average seven to eight colds or other minor illnesses per year, and grade school–aged kids average five to six.
The good news is that the germs young children encounter educate their immune systems, so when they become teenagers, pediatricians say they experience an average of only four colds per year—similar to adults.
But as common as the occasional cough and runny nose may be for kids, they’re never fun or convenient. With hopes of minimizing the sleepless nights and days missed from work, parents increasingly seek ways to support their children’s immunity, especially through the fall and winter months.
Fortunately, many of the same strategies that support healthy immune function in adults also apply to children. Eating a healthy diet, exercising outdoors, and getting restful sleep are important habits at all stages of life. There are some nuances, however, when it comes to supporting strong immune defenses in children.
Step 1: Support the Microbiome
Babies have no exposure to microbes until the day they’re born. Without having encountered germs in the womb, they have no antibodies to specific microbes, and their innate immune function is still immature. Contact with the hostile world of bacteria, viruses, and other microorganisms rapidly teaches the infant immune system to distinguish friend from foe over the first few months of life.
Some of the most critical players for training the infant immune system are the beneficial microbes that take up residence in the gut. These probiotic bacteria interact with the gut mucosa and gut-associated lymphoid tissue (GALT), where more than 70 percent of the body’s immune cells reside. Probiotic microbes not only regulate gut mucosal immunity, but also support healthy intestinal-barrier function and interact directly with potentially harmful pathogens.
Babies born vaginally get their first inoculation of bacteria as they pass through the birth canal. Breast milk continues the process of establishing the infant microbiome. According to a study published in 2018 in Frontiers in Immunology, human breast milk contains an estimated 1,000 colony-forming units (CFUs) of bacteria per milliliter, and breastfed babies are thought to ingest up to 800,000 bacteria daily. Breast milk also contains human milk oligosaccharides (HMOs), which are indigestible by the infant and act as prebiotics to encourage the growth of beneficial bacteria strains like Bifidobacterium infantis.
A balanced diet is an important part of supporting a healthy microbiome in children. Dietary fiber acts as a fermentable fuel source for beneficial gut bacteria, promoting microbial diversity which is why fruits, veggies and whole grains are important.
Prebiotic fibers, including inulin, fructo-oligosaccharides and arabinogalactans support a healthy microbiome, with resulting immune support effects. Research has demonstrated their positive influences on NK cells, macrophage activities and the complement system. Part of the mechanism is now attributed to the healthy short-chain fatty acids generated by prebiotic fermentation by the microbiota, but there may be more direct influence as research continues to try and understand additional mechanisms.
Step 2: Minimize Toxic Exposures
From toys to household cleaners to mattresses, potentially toxic compounds are everywhere. Although popularly termed endocrine-disrupting chemicals (EDCs), many of these compounds are now known to also impact immune function.
Some of the most common offenders that affect children are bisphenols (in food and drinking containers), triclosan (in hand sanitizer), parabens (in lotions), phthalates (in plastic toys), phenols (in disinfectants and plastics), and polybrominated diphenyl ethers (in flame retardants).
These and other chemicals have been found to affect the development, function, and life span of immune cells—including monocytes, neutrophils, mast cells, eosinophils, lymphocytes, and natural killer cells.
Opting for alternatives to plastic is one way that families can minimize children’s exposure to toxic chemicals. Encourage your patients to store food in glass containers, and use stainless-steel rather than plastic lunch containers. Food should always be transferred from plastic containers to ceramic or glass for microwaving. Beeswax wraps instead of plastic cling wrap can be used to cover leftover food, and stainless-steel straws can replace plastic ones.
Families can also opt for nontoxic alternatives to soaps, shampoos, lotions, and toothpaste as well as using non-toxic laundry detergent and household cleaners. Look for products that are free of parabens, phthalates, and synthetic dyes or fragrances.
Step 3: Encourage Activity
Children are meant to run around and play. Staying active helps build strong bones and muscles—and also immune function. Studies repeatedly show that frequent exercise supports immune health across all ages. Even a single bout of exercise appears to enhance immune function.
The World Health Organization and the Centers for Disease Control and Prevention recommend that children between the ages of 6 and 17 get at least 60 minutes per day of moderate to vigorous physical activity. Kids can easily spend this much time running around outdoors, riding bikes, or playing competitive games like basketball or soccer.
One reason that children often resist activity and exercise is because of the temptation of video games, movies, or other activities on screens and devices. Not only does screen time detract from time that can be spent outdoors, but studies show it also interferes with sleep.
School-aged children and teens who spend more time on devices have more trouble getting optimal amounts of shut-eye—another health habit that’s essential for immune function. Limiting screen time to less than two hours per day and emphasizing large and small motor development through physical activity and play, games, arts, crafts, reading and nature exploration supports better sleep, better learning and normal physical development.
Step 4: Optimize Nutrient Intake
Many different macronutrients and micronutrients work in concert to support immune function in both children and adults.
For example, omega-3 fatty acids serve as substrates for signaling molecules involved in immune cascades and modulate the molecular events of inflammation. Fish, grass fed or pastured milk, butter, meat, poultry and eggs can be good sources. However, many children are not accustomed to eating omega-3-rich foods and would benefit from supplementation. Liquid fish oils are nearly flavorless and can be mixed into most foods, but many children enjoy the mild lemony flavor right from the spoon.
Vitamin D is another powerful nutrient for supporting the immune response. Receptors for this vitamin are found on monocytes and macrophages and support the phagocytic abilities of these immune cells. Adequate vitamin D is also important for supporting healthy inflammatory responses in the GI tract, the skin and mucous membranes.
Vitamin D insufficiency is a widespread problem. Unless your kids are outside in the sun every day between 10 and 2pm, supplementation offers great immune benefit for children. Meta-analyses suggest that vitamin D supplementation in both adults and children support immune defenses in the respiratory tract.
Vitamin A is essential for mucosal immunity of the oral, sinus, respiratory and gastrointestinal tracts, where it not only supports the epithelial cell lining but also immune cells.
Vitamin E and selenium are important for antioxidant defenses, and magnesium is a cofactor for numerous enzymes related to immune function.
Vitamins B6, B12, and folate, along with copper and zinc, are all needed to support natural killer cell activity as part of the innate immune response.
Many of these nutrients also participate in pathways related to healthy inflammation response and oxidative stress. As you can see from table 1, there’s a clear need for a variety of essential micronutrients to support immune function.
Micronutrients Involved in Immune Function
Immune Function & Micronutrients Involved
Physical barriers—Vitamins A, D, C, E, B6, B12, and folate; iron; zinc, omega 3
Healthy inflammatory response—Vitamins A, C, E, and B6; zinc; iron; copper; selenium; magnesium, omega 3
Innate Immune Response & Micronutrients Involved
Oxidative burst—Vitamins C and E, iron, zinc, copper, selenium, magnesium
Innate immune-cell proliferation, differentiation, function, and movement—Vitamins A, D, C, E, B6, B12, and folate; zinc; iron; copper; selenium; magnesium
Adaptive Immune Response & Micronutrients Involved
T cell proliferation, differentiation and function—Vitamins A, D, C, E, B6, and B12; zinc; iron; copper; selenium
Cell-mediated immunity—Vitamins A, D, C, E, B6, B12, and folate; zinc; iron; copper; selenium
Antibody production and function—Vitamins A, D, C, E, B6, B12, and folate; zinc; copper; selenium; magnesium
Source: Gombart AF, Pierre A, and Maggini S. Nutrients 12, no. 1 (2020).
Of course, children don’t need the same micronutrient intakes as adults, and can sustain health and immune function on lower amounts. Still, children around the globe are at risk of micronutrient deficiencies, with the most common being iron, iodine, and vitamin A. Even children in industrialized countries may be at risk of micronutrient deficiencies or insufficiencies—particularly B vitamins, magnesium, zinc, vitamin D and omega 3 fatty acids.
Micronutrient deficiencies are known to compromise the immune response. Less is known about whether suboptimal nutrient levels impair immune defenses, or how to even define suboptimal levels. The recommended daily allowance (RDA) ensures that the majority of the general population won’t be deficient, but the amount of each nutrient that’s required to actually optimize immune status is not known and could potentially be much higher than the RDA.
Children can be picky eaters, at times refusing entire food groups and missing out on important nutrients. To ensure that children consume all of the essential micronutrients for immune support every day, they can take a high-quality multivitamin and mineral. Be sure it includes the full complex of B vitamins as well as an array of minerals, such as iron, magnesium, selenium, copper, and zinc. There are also children’s nutrient shake powders designed to supply optimal nutrition in a daily “smoothie”. Depending on the child’s vitamin D status, an additional vitamin D supplement may be warranted. Also consider a fish oil or other omega-3 supplement to ensure adequate intake of essential fatty acids, and probiotics or prebiotics to support the microbiome.
Step 5: Target Immune Pathways
When a child’s body is dealing with a more physiologically demanding situation, there may be an increased need for nutrients beyond the typical daily amount.
A good example is vitamin C. Although there’s less research on the amounts needed in children, adults may require as much as 6 grams per day of vitamin C to meet physiologically demanding conditions.
Vitamin C is an essential nutrient needed to support antioxidant pathways for normal redox balance and detoxification in everyone, even kids. Given the safety and low cost of vitamin C, it’s reasonable to consider daily supplementation to support immune health in children, and they usually enjoy the sweet-tart treat of chewable vitamin C- it’s an easy win.
Additional nutrients that are involved in immune pathways and may occasionally be in higher demand include vitamin A and zinc.
Vitamin A supports mucosal immunity in the skin, digestive tract, and airways. Dietary surveys indicate that most children and adolescents (ages 2-18 years) have vitamin A intakes equivalent to the estimated daily requirement, primarily due to intake of fortified milk and cereals. We know that serum retinol concentrations are decreased by inflammation and infection, and that ensuring adequate vitamin A status year-round supports a healthy immune response when needed. Vitamin A is available as a micellized liquid that is easy for children to take for a couple of days when they are beginning to feel unwell.
Zinc is a cofactor for metalloenzymes, which are required for the integrity of mucosal membranes. This mineral is also required for T cell activation and antibody production—particularly IgG. Zinc lozenges have demonstrated immune benefit when used occasionally, but the studies involved high intakes in adults.
Elderberry (Sambucus nigra) is another option for daily immune support in children. Available in juice, syrup, lozenges, gummies, or other forms, elderberry is a rich source of antioxidant compounds.
Putting Together a Plan
When you educate families on the five steps described above, you’ll help them establish a solid foundation for children’s immune health. Kids who learn at an early age how to eat healthy foods, stay active, and choose natural rather than chemical products will be at an advantage for the rest of their lives.
Summary: How to Support Immunity in Kids
Eat a balanced, high-fiber diet
Exercise at least 60 minutes a day
Sleep nine to 12 hours per night (for grade-schoolers)
Minimize exposure to synthetic chemicals in plastics and personal care products
Consider daily supplementation with a multivitamin and mineral, omega-3 fatty acids, vitamin D and probiotic or prebiotic (like larch arabinogalactan)
Consider daily or occasional supplementation with vitamin C, zinc, and elderberry
