How to boost a child’s immune system

Babies and infants have immature immune systems. Because their immune systems are still learning, they have a higher chance of getting sick. Illnesses like gastro, croup, coughs, colds, fevers, conjunctivitis and worms are all caused by different bugs that can be picked up from childcare, ELC, and primary school. 

The immune system matures gradually during infancy. Early protection against many infectious diseases previously experienced by mum occurs through the transfer of antibodies through the placenta during pregnancy and through breastmilk. Antibodies are proteins produced by the immune system that stop pathogens from invading and causing illness.

Once breastfeeding stops and this transfer of antibody protection fades away, children can become more vulnerable to illnesses. These risks are reduced by vaccinations, but as there are so many common diseases that we can’t vaccinate against, we also need to ensure that little bodies have all the right building blocks they need to develop healthy immune systems.

How often is too often for a child to be sick?

Children are more susceptible to illness because they haven’t been exposed to all these different disease causing bugs before. Once they come into contact with a pathogen, an antibody specific to it is formed. This creates immunological memory. When re-exposed to the same pathogen in the future, the immune system will now know how to fight it.

So when children are repeatedly falling ill with the same disease (hand foot and mouth is a great example of this) we know this process is faulty and needs to be supported. Ideally, most childhood infections should happen only once and then protection from the immune response is lifelong.

Nutrients needed to boost a child’s immune system

Malnutrition is one of the most common causes of poor immune function. This is because certain nutrients support immune system function and enhance resistance against infections.


Zinc is an essential nutrient, meaning our bodies can’t create or store it. For this reason, we need to consume enough through our diet each day. Zinc is used by every cell in the body for processes involving immune function, wound healing and growth and development.

Deficiency of zinc can lead to reduced immune cell activity, a reduction in the number of white blood cells, and a reduced capacity for immunological memory. A diet low in protein is the most common cause of zinc deficiency. Dietary sources of zinc include fresh meat, seafood, whole grains, beans, seeds and nuts.

Vitamin A

Vitamin A helps to protect little bodies from infections by keeping mucosal surfaces healthy. The mucosal surface is actually the largest part of the immune system. It covers the skin and tissues in the mouth, stomach, intestines and respiratory system with a protective coating that prevents nasty bugs from moving into the body.

It is estimated that 124 million children around the world are deficient in vitamin A. Subclinical deficiency is more common than overt deficiency, but both are linked to decreased immune function. Dietary sources of vitamin A include sweet potatoes, carrots, kale, spinach, red capsicum and eggs.

Vitamin C

Vitamin C plays an important role in recovery from illnesses, due to its antioxidant and immune stimulating effects. Vitamin C boosts immune cell formation (including antibody production) and improves the function of  immune cells, while also having antiallergic and anti-inflammatory properties.

Food sources of vitamin C are not limited to fruits, and includes broccoli, leafy green vegetables, sweet potato and tomatoes. Vegetables are actually a better choice for vitamin C intake, as researcher Dr John Ely actually discovered that sugar (even natural sugar) actually decreases absorption of vitamin C.

Further research has shown that when we reduce sugar intake we can improve not only vitamin C levels, but also other vitamins as well. This is research from the 1970’s, and yet supplement manufacturers are still making kids vitamin gummies with added sweeteners.

Vitamin D

Low vitamin D levels can decrease immune function and make little bodies more susceptible to illnesses. Vitamin D also assists with the absorption of calcium and phosphate. If kids are low in vitamin D, their immune system can suffer and they may not be absorbing minerals into their growing bones correctly.

Sunlight is the best source of vitamin D. Most vitamin D is made in the skin when it is exposed to the sun. Only a few foods contain vitamin D. Oily fish and egg yolks have some naturally occurring vitamin D, but most people will only absorb less than a quarter of their vitamin D needs from food sources.


Iron is needed for immune cells to replicate and mature. Iron deficiency degrades non-specific immunity (immune cells that work to find, and destroy pathogens that enter the body), leaving children vulnerable to infection and disease.

Frequent infections are a lesser-known symptom of iron deficiency. Other symptoms include fatigue, easily bruising, pale gums and pale tissue inside the eyelid.

The best way we can support immune health is by helping little bodies to develop immunological memory, then as children grow they will get sick less often. The accumulation of immunological memory is ongoing, so it is essential to support this process by providing growing bodies with the correct nutrients they need to build a strong immune system.

– Ash Yates, Children’s Health Naturopath.