Supporting immunity with functional ingredients is top of mind for many people around the world, but it can be hard to know which nutrients are truly effective and backed by science. The resources on this page provide science-based summaries about nutrition and the immune system.
The immune system is constantly active and needs energy from macronutrients like carbohydrates, fats, and proteins. Protein also supplies amino acids to build immune cells and enzymes that help destroy pathogens. These enzymes also require vitamins and minerals as cofactors to function properly.
So, while it may sound obvious, a varied and balanced diet that provides adequate nutrients is the foundation of a healthy immune system. However, some nutrients receive particular attention for their role in immune health, including vitamins A, C, and D, as well as the minerals such as zinc, selenium 1. There is also evidence for the immune benefits of other nutrients and ingredients, such as long-chain omega-3 fatty acids, probiotics, and beta-glucans 2.
Immunonutrition
Read how each of the nutrients listed below support the immune system. It is important to bear in mind that micronutrients have additional health benefits to immune health.
How the Immune System Works?
The immune system is the body’s way of protecting itself from infection by foreign invaders like bacteria and viruses. It helps the body stay healthy and recover when illness does occur and is made up of the innate (general) and adaptive (specialised) immune system 3.
The innate immune system is the body’s first line of defence. When pathogens like infectious bacteria or viruses get into the respiratory tract or gastrointestinal system, the innate immune system responds by sending cells like neutrophils or macrophages to remove the threat. These cells try to engulf the invading pathogen or create enzymes to destroy it.
The adaptive immune system specifically targets the pathogen and takes over from the innate immune system. It is often described as the ‘memory’ of the immune system. Once exposed to a pathogen, the immune system can remember the identity of that pathogen for the future and quickly mount a defence specific to that pathogen.
Impact of Age and Physical Activity on Immune Health
Immune health becomes especially important in vulnerable age groups, like infants and the elderly. Both physical and psychological stress can also compromise the immune system. Examples include over-exercising, emotional stress, and surgery.
This article was published in March 2022 and updated on June 15, 2026.
Contributor:
Kerry Health and Nutrition Institute
The KHNI was founded by Kerry to ensure science has a clear, credible voice in addressing the food and beverage sector’s toughest questions, supported by a global network of over 1,000 Kerry scientists, external collaborators, and our Scientific Advisory Council.
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References
- Eggersdorfer M, Berger MM, Calder PC, et al. (2022) Perspective: Role of Micronutrients and Omega-3 Long-Chain Polyunsaturated Fatty Acids for Immune Outcomes of Relevance to Infections in Older Adults-A Narrative Review and Call for Action. Adv Nutr 13: 1415–1430. DOI: 10.1093/advances/nmac058
- Muthuraman KR, Kato T, Kusano K, et al. (2026) β-Glucans and their roles in immune and metabolic regulation: A review. Int J Biol Macro 338: 149746. DOI: 10.1016/j.ijbiomac.2025.149746
- InformedHealth.org [Internet]. (2026) Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. In brief: The innate and adaptive immune systems. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279396/. Last accessed March 16, 2026.
