9 Key Nutrients to Strengthen Your Immune System

“Let food be thy medicine and medicine be thy food”. The foods you eat play a crucial role in maintaining and increasing the strength of your immune system. The quality of your nutrition influences the effectiveness and resilience of your immune response, which determines how you respond to disease, pathogens, infections, and other unwanted invaders. Improving the quality of your diet and consuming 9 key nutrients can help bolster your immune system, reduce the frequency of illness, and help you thrive in life.

Understanding The Immune System

The immune system is like a shield that protects you from harmful invaders such as bacteria, viruses, and other pathogens. It comprises various components, including white blood cells, antibodies, and lymphoid organs like the thymus and spleen. When a pathogen enters your body, the immune system launches a defence, identifying and neutralising the threat to keep you healthy. A well-functioning immune system is essential for survival![1]

The Link Between Nutrition and Immunity

Your diet plays a vital role in supporting immune function at every stage of life. The nutrients, vitamins, minerals, antioxidants, phytochemicals and even probiotics you get through your food provide the essential building blocks for producing and activating immune cells. The foods you consume can work for or against you, and a diet deficient in these key nutrients can compromise your immune function, making you more susceptible to becoming sick.

The Key Nutrients for A Strong Immune System

Nutritional deficiencies can significantly impact the body's immune function. Research indicates that insufficient levels of essential nutrients like zinc, selenium, iron, and vitamins A, C, D, and E can disrupt immune responses. These nutrients play vital roles in the immune system by acting as antioxidants to safeguard cells, promoting the growth and function of immune cells, and facilitating antibody production. Research suggests that individuals with inadequate nutrition are more susceptible to bacterial, viral, and other infections.[2] Here are some of the many nutrients that have been linked with enhanced immune function.

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Vitamin A

Vitamin A is crucial for a robust immune system, playing a vital role in both innate and adaptive immunity. Deficiency in this vitamin contributes to increased susceptibility to infections and impaired immune responses.[3]

Vitamin D

This vitamin is essential for immune function. It aids in lowering viral replication rates, reducing inflammation, enhancing the activity of immune cells, and modulating both innate and adaptive immune responses. Vitamin D deficiency can increase susceptibility to infections, weaken tissue barriers, and impair immune function, elevating the risk of illnesses.[3]

Vitamin C

Vitamin C is known for its antioxidant properties and helps to support the immune system by stimulating white blood cell and antibody production, both of which are essential for fighting infections. Vitamin C also aids in the production of collagen which is essential for skin integrity (the body's first line of defence). [4]

Vitamin E

Vitamin E is a potent antioxidant and protects cell membranes from oxidative damage, thereby supporting immune function. It enhances the activity of immune cells and helps regulate inflammation [5]


Zinc plays a vital role in immune cell function and development and helps to regulate inflammation. This mineral assists in wound healing, supports the activity of enzymes involved in immune responses, and helps maintain the integrity of mucosal barriers. Maintaining healthy mucosal barriers is vital for immune function as they act as protective barriers in the respiratory, gastrointestinal, and genitourinary tracts, preventing pathogens from entering the body.[4]


Selenium is a trace mineral essential for the proper functioning of the immune system. Selenium helps regulate inflammation, supports the activity of antioxidant enzymes, and enhances immune cell function.[4]


Iron is crucial for immune cell proliferation and immune function. It plays a vital role in oxygen transport and energy production, which are necessary for immune responses.[6] Protein Protein is essential for immune function, providing the building blocks for immune cells and antibodies. It supports the immune response against pathogens and aids in tissue repair.[4]


Probiotics are live bacteria (and other microorganisms) that are beneficial for gut and overall health. A gut flourishing of probiotics is what helps to keep your gut functioning optimally, which can significantly improve your health. Probiotics enhance immune responses and reduce the risk of infections.

Strengthen Your First Line of Defence From Illness Through Your Diet

Your immune system is what protects you from foreign invaders that can make you ill and it requires key nutrients to function optimally. By incorporating more of the 9 key nutrients for your immune system into your diet, you can drastically strengthen your first line of defence to reduce the likelihood of getting sick and improve your health and well-being so that you can live life to its fullest.

Make Eating Well a Simple Lifestyle

The key to eating well and living a healthy lifestyle is to make it easy and enjoyable. Our qualified nutritionists provide tailored nutrition and meal plans that suit your body, lifestyle, and preferences so that you can become your fittest and healthiest with the least amount of effort. Find the best program for you to get started!

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[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723551/

[2] https://www.hsph.harvard.edu/nutritionsource/nutrition-and-immunity/

[3] https://ods.od.nih.gov/factsheets/ImmuneFunction-HealthProfessional/#h4

[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9772031/

[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266234/

[6] https://pubmed.ncbi.nlm.nih.gov/20878427/

About the author

Claire Toomey


Claire is our team's nutritional therapist. She has an MSc in Food, Nutrition and Health, and a BSc in Biomedical Science, and is a Certified Sports and Exercise Nutritionist. She has a passion for gut health and helping people improve their health, performance and wellbeing. She has worked with a diverse range of clients from the general population right through to those with clinical conditions and athletes.

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