ASK A NUTRITIONIST: HOW DOES VITAMIN C INTERACT WITH THE IMMUNE SYSTEM?

Vitamin C is definitely an immune system multitasker! There’s been a mountain of research since the 1930s on its use as an antiviral, and even though there continues to be much debate over whether it can prevent the common cold, there is scientific consensus that it can help us get rid of it quicker (1).

When we’re ill, our immune system is called upon and with it the need for more vitamin C.

The reason? Vitamin C is needed by both sides of our immune system. It supports our innate immunity (the inbuilt defence we’re born with) and our adaptive immunity (the special forces, if you like, in the form of antibodies and T cells, developed over time). Part of the innate immune system is the skin – our biggest barrier to the outside world. Vitamin C acts as an antioxidant helping to get rid of pathogens on the skin, protecting our cells from free radical damage that can come from toxins in the air such as cigarette smoke and pollution (2).

Two-thirds of our immune system is found in our gut, which makes sense because aside from the skin, the gut is the second biggest defence against invading pathogens. Vitamin C helps to scavenge and destroy toxins in the outer layers of the gut that separates the blood (the ‘inside’) with what’s in the gut (the ‘outside’). It enables white blood cells called neutrophils and macrophages to engulf, in a sort of Pac Man style, pathogens and cell debris. The process is called phagocytosis.

VItamin C: an immune system hero

This mighty vitamin also helps the special forces of the adaptive immune system – the lymphocytes: T and B cells. B cells are in charge of making antibodies and T cells control the immune response and help destroy cells that have been taken over by a virus. The need for vitamin C is so crucial that without sufficient levels of it, our lymphocyte production can drop significantly (3). It’s also worth noting that vitamin C increases iron absorption, a mineral that’s also an immunity essential (4).

Vitamin C is an immune system hero. Remember, when your body is busy fighting off an infection, the greater its need for this multitasking nutrient.

1. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000980.pub4/full 
2. 2017, Nutrients, Vitamin C and Immune Function
3. https://academic.oup.com/ajcn/article/71/5/1194/4729285 
4. https://pubmed.ncbi.nlm.nih.gov/17449603/