We all know how important diet and lifestyle factors are when it comes to supporting the immune system.
The immune system requires a wide range of vitamins and minerals to function properly, but today I’m looking at three of the most important ones – and these also tend to be ones that people struggle to get enough of from their diet!
Certain immune cells such as phagocytes and T-cells need vitamin C to carry out their essential tasks. These cells are important because they help to destroy invading bacteria and viruses.
Vitamin C also has a protective function within the respiratory system, helping to keep your cells and tissues strong and healthy. It’s also a potent antioxidant, which is important because many toxins such as pollution, chemical fumes and cigarette smoke enter your body through the respiratory system. In fact, smokers are very likely to be deficient in vitamin C because so much is used up trying to protect your system.
It’s therefore important to keep topped up on vitamin C so your respiratory system doesn’t become damaged, leaving it vulnerable to infection.
Natural sources: Brightly coloured fruit and veg, as well as green leafy veg – red peppers, oranges, grapefruit, strawberries, kiwi, broccoli, kale and spinach.
Supplements: Look for a supplement which sources vitamin C from nature. Avoid single large doses, and instead opt for several smaller doses throughout the day.
Zinc is one of the lesser-known immune-boosting nutrients, but it is incredibly important for a functioning immune system. Those deficient in zinc tend to have severely impaired immune function, as well as cognitive problems, decreased testosterone levels and decreased muscle mass, so it’s actually a really important mineral for the whole body!
Zinc is also particularly important for skin healing, so it can help to heal damage in the respiratory system caused by the infection – particularly from coughing or dryness in the throat. In fact, one of the common signs of zinc deficiency is mouth ulcers due to this difficulty healing small abrasions.
Researchers have also discovered that zinc helps to keep the immune system in check, preventing it from spiralling out of control in response to an infection. They have even suggested that zinc can help to prevent sepsis, an often fatal response to an infection caused by excessive inflammation1.
Sources: Oysters, red meat, fortified cereals, pumpkin seeds, oats, sesame seeds
Supplement: We’d recommend no more than 100mg of supplemented zinc per day, especially if you eat a diet rich in red meat, seafood, nuts and seeds.
You might know this as an essential vitamin for bone health due to its role in calcium regulation. However, we now know that it is also vital for immune function! The unfortunate thing is that during the winter months when we need our immune systems to be as strong as possible, our vitamin D levels are at their lowest due to the lack of sunlight!
According to the Scientific Advisory Committee on Nutrition, low levels of vitamin D are also associated with allergic conditions like hayfever, asthma and eczema. Some studies even suggest that low vitamin D can play a role in autoimmune disorders such as IBS, MS or lupus. They suggest, therefore, that vitamin D can help to regulate the immune system.
Sources: Sunlight – try to spend at least half an hour out in the sun each day. There are also a few dietary sources including cod liver oil, oily fish, fortified cereals and egg yolk.
Supplement: During the winter, a vitamin D supplement is recommended for everyone. I recommend around 10mcg or 400IU per day.
Should I be taking a supplement?
Even if you think you’re eating a healthy diet, it can be difficult to make sure you’re getting enough of each vitamin. Zinc in particular is a common deficiency because over-farming of soil has meant that many foods have naturally less zinc than they should. Vitamin D, of course, is hard to get during the winter because of the lack of sunlight.
However, it can also be difficult to know which supplements are best. My advice would be to not simply opt for whichever is strongest, because ultra-strength supplements are often unnecessary and even dangerous. Instead, try to look for supplements that are easily absorbed, such as liquid forms, and those that come from natural sources, as these will be easiest for the body to use.
The importance of balance
While it’s important to focus on the above nutrients as they are arguably the most important for the immune system, it’s important to remember that they are not the only nutrients that the immune system needs to function properly.
It also requires a range of B vitamins, selenium, copper iron, vitamin C and vitamin E, so it’s important to try to eat a healthy, balanced diet to ensure you get enough of all the nutrients you need.
Focus on eating lots of fruit and vegetables as well as nuts, seeds and pulses. On top of this, make sure to eat plenty of healthy fats, complex carbohydrates and lean protein for an overall nutritious diet.