Nutrients for Immunity

Constantly catching a cold? Is your recovery time prolonged? Here are some key immune-boosting nutrients to consider to help you support your immune function.

Zinc

Zinc has an important role in the body when it comes to the development and functioning of our immune system. The richest sources of zinc include meat, fish, and seafood, particularly oysters at 32mg per serving. While zinc tends to be better absorbed from animal sources, it’s also found in plant foods like nuts, seeds, wheat germ, and legumes, but plant foods contain phytates which reduce the absorption of zinc. Over 19 years of age, men require 11mg daily and women require 8mg.

Vitamin C

Vitamin C acts as an antioxidant and supports a healthy immune system. It’s a water-soluble vitamin, meaning that it’s not stored by the body, so it’s important to have sources daily. Eat the rainbow! Good sources of vitamin C include our bright coloured fruits and vegetables like citrus fruits, berries, tomatoes, broccoli, and peppers. While high dose vitamin C supplements may not prevent you from catching a cold, there’s some evidence that vitamin C may reduce the severity and duration of cold symptoms [1].

Iron

Iron is not only important for transporting oxygen around the body, but it also plays a key role in proper immune function. In the gut, iron is taken into the immune cells and regulates these cells, having an impact on immune responses. Additionally, iron deficiency is the most common micronutrient deficiency worldwide, which has been shown to lower immunity [2]. Sources of iron include red meat, salmon, chicken, firm tofu, wholemeal bread, and rolled oats. Men require 8mg per day and women require 18mg. Similar to zinc, iron found in plant foods is less readily absorbed and so it’s recommended that vegans consume 1.8x the recommended amount.

Protein

Dietary protein is essential for good health is it is needed to recover, repair and build. This includes building antibodies to fight infections and is needed to keep your immune system strong. Most people have no trouble meeting protein recommendations, and it can be found in meat, fish, eggs, dairy, tofu, tempeh, lentils and other legumes.

B complex vitamins

B vitamins are water-soluble and can’t be stored in the body, so we must replace them regularly in our diet. They support a strong immune system as they are needed for energy production and supporting the health of our cells. B vitamins can be found in a range of foods like legumes, meat, fish and leafy greens. Vitamin B12 is found primarily in animal-based foods, and so those who exclude meat, dairy, and eggs should consider taking a supplement or consume foods fortified with vitamin B12.

Vitamin D

Vitamin D has a number of effects within the immune system, and it is important for T-cell mediated immunity.  In fact, studies have shown that low vitamin D levels are associated with an increased risk of infection [3]. Some people may find themselves less inclined to spend time outside in the colder months, meaning less time spent in the sun which promotes vitamin D synthesis. Vitamin D can also be found in oily fish, eggs, fortified juice and sun-exposed mushrooms!

A Final Word

While we recommend considering your overall dietary pattern rather than focusing on single nutrients, these are some key nutrients when it comes to supporting your immunity! Don’t forget – managing your stress levels, getting plenty of exercise, and getting adequate sleep are also important factors in addition to your nutrition that support a healthy gut microbiota AND a healthy immune system!

References

[1] Hemilä, H., Chalker, E. Vitamin C reduces the severity of common colds: a meta-analysis. BMC Public Health 23, 2468 (2023). https://doi.org/10.1186/s12889-023-17229-8

[2] Hassan, Tamer Hasan MD; Badr, Mohamed Ahmed MD; Karam, Nehad Ahmed MD; Zkaria, Marwa MD; El Saadany, Hosam Fathy MD; Abdel Rahman, Doaa Mohamed MD; Shahbah, Doaa Abdallah MD; Al Morshedy, Salah Mohamed MD; Fathy, Manar MD; Esh, Asmaa Mohamed Hosni MD; Selim, Amal Mohamed MD. Impact of iron deficiency anemia on the function of the immune system in children. Medicine 95(47):p e5395, November 2016. | DOI: 10.1097/MD.0000000000005395

[3] Sîrbe C, Rednic S, Grama A, Pop TL. An Update on the Effects of Vitamin D on the Immune System and Autoimmune Diseases. International Journal of Molecular Sciences. 2022; 23(17):9784. https://doi.org/10.3390/ijms23179784