lots of vegetables and fruits

Back to School - Strengthening Your Little One's Immune System

As a little girl, I loved school. Yes, I was a nerd (and still am), but I loved going to school to be with my friends. I felt connected at school. I was able to build long lasting friendships with classmates. However, I tended to get sick quite often, especially with tonsilitis (that has left my tonsils quite large), colds and flus, ear infections, and stomach aches; the list goes on. When I was sick, I didn't go to school, I stayed home. But I loved school and I loved seeing my friends just as I loved learning, so I hated missing school. 

Whether your little ones love or hate school, it is important for them to go, and regardless of if they are in school or not, it's always unfortunate to have a sick child. Luckily, there are a few things that you can do to help boost their immune systems, which helps fight off the infections better and also lessens the severity if they do happen to fall ill. 

There are the common methods that everyone talks about: Vitamin C, probiotics and Vitamin D. These are staples in helping to boost and regulate the immune system, but they are also supplements. I'll be talking about these 3, along with some lifestyle and dietary things you can do to help boost the immune system of you and your kids. 

Eat lots of vegetables and fruits

Eating a healthy diet is one of the 3 Pillars of Health (the other 2 being sleep and exercise). Having half a plate full of vegetables ensures that you are getting enough nutrients and fibre in your diet. I also like to tell my patients to eat "as many colours of the rainbow" as they can. Doing this allows them to have as many different phytonutrients as possible. Not all phytonutrients do the same thing, but they are beneficial in their own way. These phytonutrients tend to be different based on the colour of the vegetable and fruit. Rich purples, reds, and blues are rich in anthocyanin (Journal of Biomedicine and Biotechnology) - which is a strong antioxidant, and anti-inflammatory, that can help your body be at it's best.

Exercise or Play

Being active strengthens our bodies by keeping our cardiovascular systems healthy and strengthening our bones (MedlinePlus). Everyone knows that exercising is good for you, but no one understands how it improves the immune system. Some of the theories I've read and liked included: 

  • Increased body temperature during and after the workout deters microbes from replicating and allows your body's defence system to work more optimally - the same way a fever works.
  • Faster blood flow and changes in your antibodies allows them to move through your body faster, catch and neutralize microbes they encounter. 
  • Exercise helps to manage stress, and therefore, decreases incidences of illness.

Studies have shown that moderate exercise has the best immunomodulating effects, and that doing regular, strenuous activity can be detrimental to the immune system (Clinical Sports Medicine)


Sleep is very important for the body and health. This is the time that the body recovers from the day's hustle and bustle, the stress inflicted to it mentally, and physically. The body recovers and heals, and builds up resources to be used the next day. Sleep can be called the best anti-oxidant you can give your body (American Journal of Physiology). Sleep and many immune functions are both influenced by the 24-hour circadian rhythm. Your body adjusts which immune cells are active throughout your sleep-wake cycle. Immune cells that actively kill bacteria and diseased cells (NK cells) are more active during the day, when you are active; while memory T cells and cells that haven't matured are the most active at night (Pflügers Archiv). Therefore, it is important that your child gets enough sleep; below is a chart of recommended hours of sleep needed for children depending on their age:

Vitamin C 

Vitamin C has been known to support and improve the function of the immune system and decreases the duration of the common cold. The mechanism of how vitamin C is able to do this is still not clear, but it is needed for certain cells of the immune system (phagocytes and T-cells) to function properly. These cells track, mark, and eat invading microbes. Vitamin C supplementation was seen to reduce viral infection and replication of the Epstein-Barr Virus (aka Mono) (Medical Science Monitor). Your body has it's own absorption limit when it comes to vitamin C. In Naturopathic School, my professor would challenge us to find our limit - take and measure the amount of vitamin C it takes you to have a Bowel Movement (BM) (because it will cause you to have a BM if you take too much, as a side effect). Knowing this number can be really useful because when you are sick, your body can absorb more vitamin C, as it uses more of it to fight off the invading microb (J. Prousky).


70-80% of your immune system is in your gut (Clinical & Experimental Immunology). Your gut is covered in bacteria, which is often referred to as your microbiota, or gut flora. These bacteria help regulate your immune system and crowd out pathogenic bacteria so that they can't take hold of your intestine which can cause problems. Your natural microbiota is dependant on the way you were born - if you were born vaginally or through a Cesarean birth - because the first microbs you are exposed to start to inhabit your gut, so whether you were exposed to your mother's bacteria or the hospital's bacteria plays a large role in the bacteria that inhabit your gut. One way to influence your microbiota is by taking probiotics which have various immunomodulating abilities depending on the strain (Dr. David Williams).  Strains such as Bifidobacteria infantis are really good for immune modulation (Gut Microbes, FEMS Immunology and Medical Microbiology), whereas, Lactobacillus fermentum are good for atopic dermatitis (Archives of Disease in Childhood).

Vitamin D 

Vitamin D modulates the passive and active immune system since there are vitamin D receptors on B cells, T cells and antigen presenting cells (Journal of Investigative Medicine). There was a study showing that supplementation with vitamin D resulted in statistically decreased incidences of influenza. (American Journal of Clinical Nutrition). Vitamin D is also able to change the concentration of different T cells, moving it from a pro-inflammatory to more of a regulatory one - allowing your body to maintain self-tolerance, which is very important because you should not be reacting and attacking your own body (Journal of Immunology). 

~ Dr. Charmagne