In the midst of a global pandemic, it's never been more vital to keep your immune system healthy. One of the easiest ways to do this is through your diet, so if you've been Googling 'vitamins for immune system', you're on the right track.
We asked Dr Carrie Ruxton, dietician at the Health and Food Supplements Information Service, and Aliza Marogy, nutritionist and founder of clinical supplement company Inessa, to talk us through the seven key vitamins your immune system relies on:
Immune system booster vitamins
When talking about immunity, we often might refer to a desire to 'boost' our immune system – but in reality, we don't actually want this to happen, as Dr Ruxton explains.
'Like many other body systems, such as blood glucose levels or brain oxygen levels, our immune response works across a tight optimal range,' she says. 'Too low, and our sluggish system will not successfully attack and contain pathogens.
'Too high, and we are at risk of developing so-called autoimmune conditions where the body’s overreactive immune response starts to attack normal healthy tissue. Examples of these conditions include type 1 diabetes, multiple sclerosis, rheumatoid arthritis and psoriasis.'
Instead, you should look make sure your immune system is functioning optimally, and that's where nutrition – getting the right vitamins for immune system – comes in.
7 vitamins for immune system health
Ensuring that you have the right balance of vitamins, minerals and essential fatty acids in your diet is crucial in providing personal protection to your immune system. Here are seven of the most important immune system vitamins:
1. Vitamin A
Vitamin A has the ability to target specific parts of the immune system directly, says Marogy. 'One way that vitamin A supports immune function is by stimulating the production and activity of lymphocytes, a type of white blood cell,' she explains. 'Lymphocytes attack invaders and help produce proteins called antibodies, which also helps to ward off infections.'
Food sources include dairy foods, broccoli, kale and eggs.
2. Vitamin C
'Your first line of defence when it comes to keeping out germs and infections is the lining of the nose, gut and lungs, of which collagen is an important component,' says Marogy. 'Vitamin C plays an essential role in synthesis of collagen; without adequate vitamin C intake, the body can’t manufacture the collagen it needs to keep these linings healthy.
'Vitamin C also supports our immune response to viruses and infections by increasing production of white blood cells, enzymes and antibodies, which all play a part in our defence system,' she adds. It also has anti-inflammatory and antioxidant effects, which are important in limiting damage caused by free radicals released during an immune response.
Food sources include citrus fruits and juices, peppers, berries and spinach.
3. Vitamin E
Vitamin E is a powerful antioxidant that helps protect body cells by strengthening their cell walls. It also supports T-cell function – 'white blood cells that are like the soldiers of your immune system,' Marogy explains – by improving the cells’ membrane defences and reducing inflammation.
'Once a T-cell has identified a pathogen, it divides over and over, making clones of itself in an attempt to overwhelm the invader,' says Marogy. 'But this immune response does not work efficiently if a lot of oxidative stress is present – for example if you’ve been smoking, stressed, or eating a poor diet.'
Food sources include vegetable oils, nuts and seeds.
4. Vitamin D
Vitamin D is one of the most important nutrients for the immune system – indeed, many immune cells have vitamin D receptors.
'Vitamin D appears to keep the immune system in check by activating T-cells when they’re needed to fight off an infection, but not allowing them to overreact,' says Marogy.
It also regulates the production of inflammatory cytokines, and helps immune cells lock onto antigens (proteins on the surface of bacteria and viruses).
Dietary sources are limited – mainly oily fish and eggs – so UK health experts recommend that everyone consider a daily supplement of 10 micrograms.
5. Vitamin B2 (riboflavin)
'Vitamin B2 is involved in maintaining healthy red blood cells, which play a role in the healthy functioning of the immune system,' says Marogy. It also has an antioxidant effect to help strengthen your immune system against infection.
Food sources include eggs, lean meats and green vegetables.
6. Vitamin B6
'Vitamin B6 is utilised by the body to make immune cells and can help increase the number of infection-fighting antibodies,' says Marogy. 'It also acts as a channel of communication between cytokines and chemokines, two signalling proteins used by the immune system when encountering a foreign invader.'
A wide range of foods contain vitamin B6, but meat, fish, tofu, bananas and potatoes are particularly rich sources.
7. Folate (B9)
Folate can be beneficial to supporting immune function, particularly as you age. 'Whenever a virus enters your body, T-cells jump into action, proliferating rapidly,' says Marogy. 'As you age, you naturally produce fewer T-cells as the years go by. However, folate can help T-cells to proliferate again.'
3 supplements to boost immune system:
Fortify your immune system's defences by making sure you're getting an adequate amount of the following supplements:
Selenium deficiency is associated with impaired immune function, says Marogy. 'People with inadequate levels of selenium have been shown to have lesser amounts of T-cells and a reduced ability to respond to viral infections,' she says. 'Selenium also plays a role in the production of cytokines – molecules that play an important role in coordinating the immune system.'
When people are low in zinc, the immune response is the first to suffer and there is a greater risk of oxidative stress and inflammation.
'Zinc is particularly important when it comes to warding off infections as we age, owing to the role it plays in the health of the thymus gland – which produces infection-killing T-cells,' says Marogy.
Food sources include seafood, pork and beans.
3. Omega-3 fatty acids
The most important omega-3 fatty acids for a healthy immune system are DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). They assist in reducing inflammation and promoting healing after any bacteria and viruses have been neutralised.
Natural dietary sources are limited to oily fish and seafood, so supplements containing fish oil or algae (if you're vegan) are important alternatives if you don’t eat fish regularly.
The bottom line
You can’t control our environment – including the bacteria, viruses and yeast that could potentially cause infection – but you can do everything possible to get your immune system ready to respond, says Dr Ruxton.
'Certain nutrients can help, and a daily multivitamin and multimineral supplement, plus a fish oil supplement if you don’t regularly eat oily fish, is worth considering and is good, common sense,' she adds.
Last updated: 02-06-2020