Essential vitamins that will keep your immune system strong, backed by research

  • PUBLISHED November 02, 2023
  • AUTHOR Donna

Key takeaways

  • Eating the right vitamin-rich food is key for a fine-tuned immune system that can ward off viruses.
  • Certain micronutrients such as vitamins A, B, C, D, zinc and curcumin have been shown to be effective in the fight against infections. Some can even help you get on your feet faster when you’re already ill.
  • Most vitamins and minerals can be found in a balanced, everyday diet. But some, in particular vitamins B₁₂ and D, are harder to come by. In these cases, supplements can come in handy.

Essential vitamins that will keep your immune system strong, backed by research

The resilience of your immune system is largely defined by an interplay of lifestyle choices, genetics and diet. 1 2 Of course, you may still catch the flu regardless of how hard you maintain immunity, but if you eat healthily, exercise regularly and manage stress, the illness may not last as long and you could be on your feet again quicker.

In building the strength of your body to ward off infection, vitamins and minerals seem to play a key role. Studies show that even a marginal deficiency in certain micronutrients can lead to a weaker immune system. 3 Eating the right foods is therefore essential for keeping your natural protection apparatus ready to strike when necessary.

In this article, you’ll learn about the vitamins that are scientifically proven to offer support – some are abundant in a balanced diet; others may require a supplement to give your body an extra boost.

Folic acid and other B vitamins

Vitamins B are a group of eight related nutrients. Each is responsible for a wide range of metabolic and regulatory processes which are essential for your health. 4

One of the most prolific among B vitamins is folic acid or B₉. Long known to support a healthy pregnancy 5 , folic acid is also an important building block of a strong immune system. 6 A Canadian study with rats found that a folic acid-rich diet could boost body defenses by increasing T-cell distribution, which has especially important implications for the immunity of older people – as we grow older, T-cell levels quickly decline. 7

Lack of folic acid, on the other hand, can alter immune response, lead to inflammation and can cause sickness. 8 Luckily, many foods are good sources of folate (the name for naturally occurring folic acid). So, next time you go folate-shopping, make sure to stock up on broccoli and leafy green veggies such as kale, but also oranges or liver – these are all wonderful sources of the vitamin. 9 But if you need to increase your dose with a supplement, look no further than Donna’s QUTE PRENATAL capsules.

Folic acid’s cousin, vitamin B₁₂, is another powerhouse vitamin. Without the precious vitamin, your body might “drastically alter immune responses by affecting the production and activity of white blood cells”. 10 Vitamin B₁₂ is essential for red blood cell production which ensures the immune system receives enough oxygen. For this reason, B₁₂ should be a part of a healthy diet, a recent study suggests 11 , although receiving the needed amount can be trickier for the elderly and vegans. 12 Vitamin B₁₂ is mostly found in meat, fish and dairy products. 13 If these foods can’t be on your everyday menu, consider taking a supplement. Adults will need 1.5 micrograms a day. 14

Similarly, vitamin B₆ also keeps the immune system strong by making new red blood cells and transporting oxygen throughout the body. A 2017 study found that decreased levels of B₆ may cause mood changes and reduce antibodies needed to avoid infections. 15

Vitamin C

Vitamin C is a powerful antioxidant. It works against inflammation and fortifies white blood cells, protecting your cells against oxidative stress which is known to cause chronic diseases. 16

Studies have found that supplemental vitamin C lowers the severity and duration of a cold by eight percent in adults and 14 percent in children. 17 , 18 It may also help you recover faster as it helps clear out old cells by replacing them with new ones. 19 Not getting enough of the famed vitamin can have consequences – vitamin C deficiency has been linked to poor immune function and increased susceptibility to infections. 20

Our bodies cannot manufacture or store vitamin C. 21 It needs to be constantly replenished, especially during infections. The proverbial citrus fruits indeed have a high concentration of the micronutrient, but you could also go for certain vegetables to replenish your body with vitamin C. Bell pepper, broccoli, spinach, kale and Brussels sprouts are all great sources. 22

What about dosages? Women+ should aim to receive 75 milligrams of vitamin C and men+ 90 milligrams each day. The upper limit for all adults is 2,000 milligrams a day. 23 Supplemental daily doses are typically between 250 and 1,000 milligrams.

Vitamin A

Vitamin A also plays a vital role in maintaining your body’s natural defenses. It is known as an anti-inflammation vitamin and it’s involved in the production of white blood cells, which help capture and clear bacteria and other pathogens from your bloodstream. 24 Deficiency in vitamin A can increase your susceptibility to infections and delay your recovery when you get sick. 25 26

The two main forms of vitamin A in the human diet are preformed vitamin A (retinol) and provitamin A such as beta-carotene which is converted to retinol in your liver. 27 28 Preformed vitamin A mainly comes from animal products, cheese, eggs, oily fish, milk, yogurt and liver. Conversely, good sources of beta-carotene are fruits and vegetables such as spinach, broccoli, carrots, sweet potatoes, squash (orange and yellow vegetables in general), red bell pepper and mango. 29

You should be able to get all the vitamin A you need from your diet. 30 Besides, any vitamin A your body doesn’t immediately put to work is stored for future use. It’s recommended that men+ get 900 micrograms and women+ 700 micrograms of the vitamin daily. 31

Vitamin D

Vitamin D is massively important for the immune system to operate in peak condition. It enhances the pathogen-fighting white blood cells that help strengthen your defenses against diseases. It also decreases inflammation which helps promote the immune response. 32 In addition, clinical trials suggest that supplementation may help prevent or treat the common cold – researchers have put vitamin D in the same category as zinc, vitamin C and the Echinacea plant which have the same abilities. 33

Vitamin D can further reduce the frequency of upper respiratory infections, including influenza. 34 Indeed, a 2019 review showed that supplementing with vitamin D “significantly” decreased the risk of respiratory infections in people deficient in this vitamin and lowered infection risk in those with adequate levels. 35

Vitamin D is crucial to so many aspects of our immune functions but most people didn’t yet get the memo. 36 Deficiency is a worldwide issue. 37 In the US alone, nearly 95 percent of the population is not meeting the daily requirements. 38 This is not entirely surprising as vitamin D is not abundant and can only be found in specific foods such as red meat, beef liver, egg yolks and oily fish like salmon and sardines. It’s also formed in human skin under the influence of the sun’s ultraviolet light. 39

Most people, therefore, could benefit from vitamin supplementation, especially in winter months. Adults need 10 micrograms a day which translates to around 400 international units (IU). 40 Jump over to Donna’s QUBIX D3 and learn more about our vitamin D supplement.


Zinc is an important mineral in combating viruses. It has also been shown to shorten the duration of a cold when given as a supplement. 41

Research suggests that zinc has a direct effect on the production and function of white blood cells. 42 It may also act as an immunostimulant – a component that increases the effectiveness of the immune system response. 43

Supplementing with zinc may even be beneficial for those who are already sick. A study of hospitalized children with acute lower respiratory tract infections showed that taking 30 micrograms of zinc per day decreased the total duration of infection and the duration of the hospital stay by an average of two days, compared with the placebo group. 44

Not getting enough of the mineral, on the other hand, might spell trouble – a deficiency in zinc could significantly affect your immune system’s ability to function properly, resulting in an increased risk of infection and disease, including pneumonia, studies show. 45 46

You can find zinc in many common food staples, such as whole grains, dairy products, meat, lentils or nuts. 47 Zinc is also found in oysters, beef and crab. 48 Taking zinc long term is typically safe for adults, as long as you follow the recommended intake, set between 15 and 30 milligrams per day. 49


Used for thousands of years, curcumin is a yellow pigment found primarily in turmeric – a plant of the ginger family known as a curry spice. Curcumin is a polyphenol, lauded for its anti-inflammatory and other health properties.

There are more than hundred clinical trials showing the effectiveness of curcumin in treating diseases ranging from autoimmunity to Alzheimer’s disease. 50 All this might be due in part to the ability of curcumin to modulate the immune system. 51 52 In addition, curcumin also improves the health of our gut bacteria, which adds to our overall immune health. 53

Because curcumin is not absorbed well, it’s generally recommended to supplement it with 1,000 milligrams per day. To increase absorption, you can pair curcumin with a black pepper extract.

Tell us what works for you

This is our selection of essential vitamins and minerals which are approved by science to help strengthen the immune system. What is your go-to remedy when you feel under the weather? Reach out to us through emailInstagram or Facebook and let us know.


Article overview


Explore more

Feed your curiosity with more content. Dive deeper and explore our selected articles, curated just for you.

This site is registered on as a development site.