top of page

Naturopath's Immunity Support

Listen to the podcast interview I did on natural immune system support with Roxanne from Simply Kids Wellness here.

There are some key nutrients that the body’s immune system requires in order to do its job of protecting the body from infections. Exposure to certain elements can also suppress the function of the immune system. When we are aware of these factors, we can then choose to support our immune systems with foods that contain these nutrients and specific foods that have immune boosting or anti-viral properties and we can minimise factors that suppress immune function.

Vitamin C

In short:

Vitamin C is required for immune function and to reduce susceptibility to infections.

The science:

Adequate vitamin C needs to be consumed for the immune system to function well. Immunity is impaired when there is a deficiency of vitamin C, leading to an increased susceptibility to infections [1]. Vitamin C supplementation seems to be able to prevent and treat respiratory and systemic infections [1]. Vitamin C concentrations in the blood plasma quickly decline during infections [2] due to inflammatory and metabolic requirements [1] thus increasing the body’s requirements for vitamin C [1].

Supplementation of vitamin C has been found to improve elements of the immune system, such as antimicrobial and natural killer (NK) cell action, lymphocyte proliferation (white blood cells especially in the lymphatic system), chemotaxis and delayed-type hypersensitivity (allergic immune reaction) [2].

When utilising vitamin C to prevent infection, the dosage amount needs to be able to offer adequate to saturated blood plasma levels to optimise cell and tissue levels. This amount may be 100-200mg/day in adults [1]. When there is an infection already present, the amount of vitamin C intake required to compensate for the increased inflammation and metabolic demand increases to a higher dose in the grams[1].

Food Sources of Vitamin C: Citrus fruits - oranges, lemons, limes; broccoli, brussel sprouts. kiwi fruit, fruits, vegetables, red and green capsicum, broccoli, aloe vera juice, parsley, tomatoes, potatoes, raw cabbage, sweet potatoes.

Vitamin C is destroyed by cooking so eat these foods raw or lightly steamed to maximise your vitamin C ingestion. Light exposure can also destroy vitamin C.


In short:

Zinc is required for immune function.

The science:

Zinc is required for more than 300 enzymatic processes in the body. These processes have an effect on the function of bodily organs and also a secondary effect on the immune system [3].

Adequate zinc levels in the body are required for immune function. A deficiency of zinc has been shown to impair cellular mediators of innate immunity such as phagocytosis and NK cell activity [2]. Zinc has a direct effect on the production, maturation and function of white blood cells (leukocytes) [3].

Zinc and vitamin C are both crucial to immune function to reduce the risk, severity and duration of infectious disease [2]. When there is adequate intake of vitamin C and zinc, there can be an improvement in the symptoms and shortened duration of respiratory tract infections [2].

Food Sources of Zinc: capsicum, nuts such as cashews and almonds, seeds: pumpkin, sunflower and sesame seeds; meat, egg yolks, ginger, legumes such as chickpeas- sprout or soak chickpeas to reduce phytates which reduce mineral absorption.

Maximise Nutrients in Your Food

Certain vitamins and minerals are susceptible to destruction via conditions such as: heating, light, milling (of grains), freezing, cooking, canning.

When preparing your meals, try these methods to minimise nutrient loss:

- Raw

- Lightly steamed

- Lightly stir-fried in water


In short:

Mushrooms may support immune function.

The science:

Mushrooms contain a constituent called beta-glucan, and beta-glucan has been found to have a supportive effect on the immune system. Beta-glucans increase host immune defence by activating complement system (part of the immune system that enhances clearance of microbes and damaged cells amongst other actions), enhancing macrophages and NK cell function [4].


In short:

Garlic may be used in the prevention and treatment of viral infections.

The science:

Garlic contains many constituents, one of which is known as active organosulfur compounds (OSCs). Garlic has been studied for its many health benefits, one of which is its effect on the immune system. Garlic and its OSCs have an immunomodulatory effect that has been linked to an improvement of viral infection [5]. Garlic has been demonstrated to be of use in prevention of widespread viral infections through an enhancement of the immune response [5]. Garlic has significant antiviral activity [5].

Probiotics and Prebiotics

Probiotics are live organisms, usually bacteria, and contribute to a healthy microbiome. Prebiotics are special types of plant fibres that stimulate the growth of healthy bacteria in the gut.

In short:

For overall health including immunity, including foods that are particularly high in pre and probiotics may be of benefit.

The science:

A large portion of our immune system resides in our gut. In the lumen and upper part of the mucus layer of the gastrointestinal tract (GIT) lives an abundance of microorganisms. These microorganisms create a micro-ecosystem called the microbiome. The composition of these microorganisms have an effect on the gut barrier and gut immune system [6], as well as our overall health, mood and much more.

Probiotics may help with intestinal barrier integrity as well as modulation of the immune system. Probiotics may modulate the immune system by increasing the action of NK cells and macrophages, modulate the secretion of cytokines or immunoglobulins, or by improving gut barrier integrity [6].

Specific species and strains of probiotics have specific effects [7], this is of particular importance when you are wanting to utilise probiotics for specific therapeutic outcomes. It seems that the timing of intervention with probiotics is important, with possibly the greatest effects earlier in life [7].

Food sources of probiotics: kim chi, sauerkraut, good quality yoghurt (check for probiotic count and less than 10grams of sugar per serve) - natural rather than flavoured yoghurts tend to be lower in sugar.

Food sources of prebiotics: fruits, vegetables, especially those that contain complex carbohydrates such as fibre and resistant starch. As these types of carbohydrates are not digestible by the body, they pass through the digestive system and the microbes consume them. Garlic, onions, bananas, oats, apples to name a few.