A Healthy Immune System

What is the Immune System?

Your immune system is your bodies first line of defence and on the whole it’s very clever at defending your body. Several factors influence how efficiently your immune system works such as age, life stage, medical conditions, lifestyle and diet.

How can I Support a Healthy Immune System?

It’s easy to look for solutions to ‘boost’ your immune system, but there’s little evidence to show this is actually possible. Instead, making the right diet and lifestyle choice can best support a normal, healthy, functioning immune system.

Let’s take a look at what these are…

  1. Avoid the use of tobacco - tobacco use, particularly smoking, can considerably lower immune function.
  2. Choose a healthy, balanced diet – high in fruits, vegetables and wholegrains with plenty of colour and variety.
  3. Keep active – aim for 150 minutes over the week, anything that raises your heart rate!
  4. Maintain a healthy weight - check if you're a healthy weight here.
  5. Get enough quality sleep - find out how here.
  6. Maintain good food hygiene and hand washing to avoid infections.

What’s the link With My Diet?

Even the best diets can’t ‘boost’ an immune system or provide extra protection, however a healthy, balanced diet provides the vitamins and minerals your immune system needs to function at its best.

Having very low levels, known as a deficiency, of key vitamins and minerals has been linked with a reduced functioning immune system (including vitamins A, C, D, E, B vitamins, folic acid, iron, selenium and zinc). The World Health Organisation has identified that deficiencies in vitamin A, zinc and iron are prevalent across much of the world, particularly in women and children, so increasing these nutrients in our diets can help to support a healthy immune system.

For most vitamins and minerals, there’s no need to reach for the supplements as there’s often plenty of food sources available in our diets – if our diets are varied and well balanced.

Take a look below at some of the main food sources of these vitamins and minerals


  • World Health Organisation. Fact Files on Nutrition. 2017. Available at: https://www.who.int/features/factfiles/nutrition/en/
  • Maggini, S; Pierre, A and Calder, P. (2018) Immune Function and Micronutrient Requirements Change Over the Life Course. Nutrients 10 (10): 1531
  • Chandra, R. (2002) Nutrition and The Immune System From Birth to Old Age. European Journal of Clinical Nutrition. 56 Supp 3:73-6
  • United States Department of Agriculture, Agricultural Research Service. FoodData Central, 2019. Available at: fdc.nal.usda.gov.
  • Public Health England. McCance and Widdowson’s The Composition of Foods Integrated Dataset. 2019. Available at: gov.uk/government/publications/composition-of-foods-integrated-dataset-cofid