My toddler has been sick once in his life.  Once.  And he was under circumstances of high emotional, chemical, and physical stress and in a location of high germ exposure that one time.  He has not been in a bubble or isolated in any way from germs.  At 4 months he was on a cross-country plane trip during cold & flu season, he’s chewed on community toys at the library, he’s kissed other little kids.  I don’t do anything special or make fancy herbal concoctions.  What I do is follow the advice I give my patients in addition to washing his hands with soap and water before meals and a bath at night.  Maybe I have been lucky, but I believe increasing health really can make a child disease resistant.  What follows is everything I do for his health.  It may be one, a few, or all of these things, or just plain luck that keeps my child from getting sick; but if your child is the one who always catches the bug, you might try something different.

The germ theory of disease is well accepted, it has two parts:  A) a ‘germ’ is the agent that makes you sick & B) the ‘germ’ will only be successful in a specific environment.  If you do not want your child to live in a sterile bubble forever, you cannot put all your effort into part A.  Reasonable efforts in sanitation are important, such as washing your hands, and supporting a clean water supply.  Besides these simple preventative measures, you should put the bulk of your efforts into making your child a terrible environment for germ survival.

1. Chiropractic Adjustments.  My son has had chiropractic care since day 2.  If the nervous system is working optimally, it can focus on other problems, like fighting sickness.  My son had lots of adjustments as a baby because his birth wasn’t easy and he had lots going on.  Once he was ‘up and running’ he was doing better.  His spine is checked at least once a month, more if he’s doing crazy stuff like taking big falls or seems to be having a rough time emotionally.
2. Breastfeeding.  Entire books have been written on the immune system benefits of breastfeeding.  Breast really is best.  Not all babies have this advantage for one reason or another, this is not a mom failure, this is a society failure.  We need to do better for our moms & babies.  That aside, my son is a toddler, and I still nurse on demand.  Some research suggests that children should nurse until the immune system is fully developed at age 6.
3. Love.  You didn’t expect to see this on this list, especially at #3.  The more I learn about emotional health, the more I believe it to be one of the most important and most neglected pieces of health.  Love your child.  Hug them.  Kiss them.  Snuggle them.  Support them emotionally.  A child needs to know they are loved in order to truly thrive.
4. Happiness.  Yes, happiness counts, see #3.  I don’t mean give them what they want to make them happy, but I DO mean give them what they need:  love, snuggles, food, water, your attention.  Teach them approach the world in a way that it’s not so scary or hard.  Help them find happiness in their life, in the simple things.
5. Parental contact.  Yep, skin-to-skin is powerful stuff.  For little kids and babies literal skin to skin with a parent is appropriate and necessary to hit the reset button sometimes, it can help regulate their nervous system and the rest of their physiology.  Hug your kids of any age often.  Wear your babies and toddlers.  Having a parent in physical contact can be huge.
6. Physical Activity.  Kids should play often and hard.  Let your child run around and explore.  Little kids do this for lots of really good innate reasons.  Hopefully you can preserve this and you won’t have to twist their arm later in life to get off the couch.  Your child doesn’t NEED and organized sport to get exercise, but many parents find this a good way to make sure their little ones are moving their bodies.  Bikes, parks, etc. are your best friend.
7. Fresh air.  I don’t care what the weather is; dress for it.  Babies in Norway are put in strollers to nap outside year round for good health.  My son naps indoors, but he gets outside every day for at least an hour.  Stale air is the worst and it’s almost always stale inside.  Bonus:  humidify your indoor air when it’s dry, dry air is irritating to the respiratory system.
8. Sleep.  If you are doing all of the above, your child will naturally want to sleep and they should.  Sleep is when your body repairs itself and it’s vitally important for your whole health.  Sleep is a basic need, right up there with oxygen, food, water, and shelter.
9. Microbiome care.  Everyone has a microbiome, these are the bacteria, fungi, and viruses that coat our entire body and digestive tract.  You want this to be a diverse, health-promoting group.  They fight off all the bad guys for you, digest your food, and generally help us survive & thrive.  Some people take probiotics, and I gave my son some as a newborn, but I believe probiotic supplements to be a stop gap measure.  It is far better to nourish your microbiome through food and proper exposures.  Proper exposures to acquire a healthy microbiome include:  a vaginal birth, breastfeeding, playing in dirt, having pets-especially dogs, eating fermented foods (yogurt, kefir, kimchi, sauerkraut, fermented pickles, etc).  Caring for your microbiome includes: avoiding processed foods, eating plant foods (fruit, veggies, beans, nuts, seeds, whole grains), avoiding antibiotics when possible (especially in soap!), and not sterilizing things-soap and water work just fine in daily life.
10. Healthy, whole foods diet.  Processed food isn’t food, it is a stressor.  Eat real foods that have been around for generations:  fruit, veggies, whole grains, beans, nuts, seeds, meat, fish, dairy.  Sugar is not good for anyone, but it is part of our modern life.  It impairs immunity.  Try a ‘sugar budget’ for added sugar to not overwhelm your body (naturally occurring sugars, e.g. fruit, is free):  4 grams=1 tsp of sugar.  Kids 12 and under should only have a maximum of 3 tsp/day.  (Adults:  women 4 tsp, men 9 tsp.)  My child doesn’t know processed foods: no puffs, cereal, fruit snacks, etc.  He’s always eaten what we do once he started having solid food.  His current favorite snack is grape halves.  He eats pretty much everything, even Brussel sprouts.
11. Vitamin D.  We are all deficient if we live north of Arizona.  Supplements are necessary.  How much?  More information at Vitamin D council.  Drops are typically easier to give kids.  My son has been taking Vitamin D since infancy and likes his drops that are in organic olive oil.
12. Avoid Toxins.  You can’t avoid them completely and live on this planet.  I like it here, so I do what I can.  We use non-toxic cleaning and personal care products.  We eat lots of organic foods, but we aren’t perfect, but do make an effort to observe the Clean 15/Dirty 12.  Tap water is plentiful, but has it’s issues.  We use a Britta filter, but I am considering putting in a reverse osmosis system under the sink, they are more affordable than you think.  When we choose fish we make lower mercury choices.  I try to live lightly on the planet, because everything counts when it comes to polluting our planet.  If you haven’t clicked on any of these links, the Environmental Working Group is where I go to get help on lowering our toxin load.

This is a lot, try one new thing from this list at a time and slowly build a healthier child this season.