Most of the time, the immune system does its job to keep us healthy. However, the system sometimes fails to defend, and this can result in illness, infection, or diseases. This is where the body then needs reinforcements in the form of vitamins and other immune-boosting nutrients. And in this article, we will detail the best vitamins for immune system health.
Your immune system contains tissues, antibodies, white blood cells, chemicals, and all the organs of the lymphatic system, which work together to protect you. They form your first line of defense against invaders such as microorganisms and germs. Interestingly enough, about 80% of the immune system is found your digestive system; therefore, when gut bacteria are balanced, so is the immune system.
Read on to learn what vitamins work together with your microbiome for a strong and healthy immune system.
In This Article:
Best Vitamins for Immune System Health
A lack of adequate nutrition is one of the key components of a compromised immune system. Fortunately, vitamins have properties that help protect the immune system and fight against disease, illness, and infection. It is possible to get vitamins from foods in the diet, as well as from supplements.
Some vitamins have more immune-protecting power than others do. The best vitamins for immune system health featured in this section include vitamin C, vitamin B6, vitamin E, vitamin D3, vitamin A, vitamin B9 (folate or folic acid), and vitamin K.
Each vitamin will also feature a table that details the recommended daily allowance for that particular vitamin.
1. Vitamin C
Vitamin C (ascorbic acid) is one of the biggest immune boosters. It is a water-soluble, antioxidant vitamin that plays a vital role in individuals with a weakened immune system due to stress.
A sufficient vitamin C intake could help you fight off viruses, colds, and other complications like lung infections and pneumonia. Conversely, a weak immune system due to vitamin C deficiency might make any infection more severe, and this is even worse among older adults.
Several cells in the immune system can accumulate vitamin C, including T cells and phagocytes. As more immune cells take in vitamin C, this leads to an increase in directed movement to the infection location and increased proliferation of lymphocytes and other immune cells.
The increase of vitamin C also promotes a spike in production of immune-boosting proteins with cell proliferation. This forms a network that leads to a strong immune system. As an antioxidant, vitamin C is also thought to neutralize free radicals that may otherwise damage cells.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin C daily:
|0-6 months||40 mg||40 mg||–||–|
|7-12 months||50 mg||50 mg||–||–|
|1-3 years||15 mg||15 mg||–||–|
|4-8 years||25 mg||25 mg||–||–|
|9-13 years||45 mg||45 mg||–||–|
|14-18 years||75 mg||65 mg||80 mg||115 mg|
|19+ years||90 mg||75 mg||85 mg||120 mg|
Smokers require 35 mg per day more of vitamin C than non-smokers.
2. Vitamin B6
Vitamin B6 (pyridoxine) is a B-complex vitamin that plays a critical role in energy levels and immunity. A vitamin B6 deficiency will also lead to fatigue, low energy, and chronic pain. Research shows that large doses of vitamin B6 supplementation (50 mg or 100 mg daily) can increase immune response in critically ill patients.
Adequate vitamin B6 intake is especially vital for an optimal immune system, especially in the elderly. Chronic inflammation will also trigger tryptophan degradation and may trigger pyridoxal 5’-phosphate (PLP) loss, which increases the requirement of vitamin B6.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin B6 per day:
|0-6 months||100 mcg||100 mcg||–||–|
|7-12 months||300 mcg||300 mcg||–||–|
|1-3 years||500 mcg||500 mcg||–||–|
|4-8 years||600 mcg||600 mcg||–||–|
|9-13 years||1.0 mg||1.0 mg||–||–|
|14-18 years||1.3 mg||1.2 mg||1.9 mg||2.0 mg|
|19-50 years||1.3 mg||1.3 mg||1.9 mg||2.0 mg|
|51+ years||1.7 mg||1.5 mg||–||–|
3. Vitamin E
Vitamin E (tocopherol) is a very powerful antioxidant vitamin that helps boost immunity and fight infection. A vitamin E deficiency leads to increased infectious diseases and tumors.
Research shows that low vitamin E levels are linked with digestive problems, including poor nutrient absorption in the digestive tract. This leads to all sorts of immune issues, including damaged skin, hormonal problems, eye disorders, nerve and muscle damage, and inflammation.
On the other hand, vitamin E from food and supplementation can help induce higher differentiation of immature T cells in the thymus that leads to improved immunity, especially in the elderly.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin E daily:
|0-6 months||4 mg (6 IU)||4 mg (6 IU)||–||–|
|7-12 months||5 mg (7.5 IU)||5 mg (7.5 IU)||–||–|
|1-3 years||6 mg (9 IU)||6 mg (9 IU)||–||–|
|4-8 years||7 mg (10.4 IU)||7 mg (10.4 IU)||–||–|
|9-13 years||11 mg (16.4 IU)||11 mg (16.4 IU)||–||–|
|14-18 years||15 mg (22.4 IU)||15 mg (22.4 IU)||15 mg (22.4 IU)||19 mg (28.4 IU)|
|19+ years||15 mg (22.4 IU)||15 mg (22.4 IU)||15 mg (22.4 IU)||19 mg (28.4 IU)|
4. Vitamin D3
Vitamin D3 (cholecalciferol) is a fat-soluble vitamin found in food and supplements. Vitamin D is among the best vitamins for immune system health since it can help reduce inflammation; fight bacteria and viruses; and regulate differentiation, cell proliferation, and cell death.
As a result, an adequate vitamin D intake could potentially help fight the common cold, flu, and autoimmune disorders like multiple sclerosis and rheumatoid arthritis.
How else can vitamin D boost immune health? Vitamin D is sent to immune cells that contain vitamin D receptors. Macrophages are specific immune cells that recognize lipopolysaccharides (LPS) through Toll-like receptors (TLRs). When these receptors bind with LPS, this leads to vitamin D3 helping in the transcription process of proteins that later destroy pathogenic cells.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin D3 daily:
|0-12 months||10 mcg (400 IU)||10 mcg (400 IU)||–||–|
|1-13 years||15 mcg (600 IU)||15 mcg (600 IU)||–||–|
|14-18 years||15 mcg (600 IU)||15 mcg (600 IU)||15 mcg (600 IU)||15 mcg (600 IU)|
|19-70 years||15 mcg (600 IU)||15 mcg (600 IU)||15 mcg (600 IU)||15 mcg (600 IU)|
|71 years and older||20 mcg (800 IU)||20 mcg (800 IU)||–||–|
5. Vitamin A
Vitamin A (retinol and beta-carotene) is a fat-soluble vitamin and powerful antioxidant that plays a vital role in enhancing immune system function. Genes involved in immune response are regulated by vitamin A, which is needed for fighting illnesses like the common cold or flu, and more serious conditions like autoimmune diseases and cancer.
A vitamin A deficiency leads to respiratory infections, premature skin damage, and digestive issues. Insufficient intake will also impair immunity by diminishing the function of immune cells like natural killer cells, macrophages, and neutrophils.
Vitamin A deficiency also diminishes antibody-mediated responses directed from both T-helper (Th) cells since vitamin A plays a role in the development of both Th cells and B cells.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin A per day:
|0-6 months||400 mcg (1,333 IU)||400 mcg (1,333 IU)||–||–|
|7-12 months||500 mcg (1,666 IU)||500 mcg (1,666 IU)||–||–|
|1-3 months||300 mcg (1,000 IU)||300 mcg (1,000 IU)||–||–|
|4-8 years||400 mcg (1,333 IU)||400 mcg (1,333 IU)||–||–|
|9-13 years||600 mcg (2,000 IU)||600 mcg (2,000 IU)||–||–|
|14-18 years||900 mcg (3,000 IU)||700 mcg (2,333 IU)||750 mcg (2,500 IU)||1,200 mcg (4,000 IU)|
|19-50 years||900 mcg (3,000 IU)||700 mcg (2,333 IU)||770 mcg (2,700 IU)||1,300 mcg (4,333 IU)|
|51+ years||900 mcg (3,000 IU)||700 mcg (2,333 IU)||–||–|
6. Folic Acid (Vitamin B9)
Folate (synthetic folic acid) is also called vitamin B9. Common signs of folate deficiency include poor immune function and frequently getting sick; chronic low energy; canker sores; anemia; pale skin; and digestive issues like bloating, constipation, and IBS (irritable bowel syndrome).
Folate also promotes proper production and function of white blood cells. Research shows that folate increases T cell distribution and cell division to increase immunity. T cells are lymphocytes that play a major role in immunity.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin B9 (folate) daily:
|0-6 months||65 mcg||65 mcg|
|7-12 months||80 mcg||80 mcg|
|1-3 years||150 mcg||150 mcg|
|4-8 years||200 mcg||200 mcg||–||–|
|9-13 years||300 mcg||300 mcg||–||–|
|14+ years||400 mcg||400 mcg||600 mcg||500 mcg|
7. Vitamin K
Vitamin K is an essential fat-soluble vitamin involved in heart and bone health; however, it is also among the best vitamins for immune system health. The vitamin K that we absorb from our diet is related to intestinal bacteria; therefore, our current vitamin K levels depend greatly on our digestive health.
A vitamin K deficiency can lead to IBS, inflammatory bowel disease, leaky gut syndrome, and other intestinal problems. Other conditions that prevent the body from absorbing vitamin K include liver disease, gallbladder disease, celiac disease, and gluten sensitivity.
According to the Institute of Medicine at the National Academy of Sciences, the following is the recommended dietary allowance (RDA) for vitamin K daily:
|0-6 months||2.0 mcg||2.0 mcg|
|7-12 months||2.5 mcg||2.5 mcg||–||–|
|1-3 years||30 mcg||30 mcg||–||–|
|4-8 years||55 mcg||55 mcg||–||–|
|9-13 years||60 mcg||60 mcg||–||–|
|14-18 years||75 mcg||75 mcg||75 mcg||75 mcg|
|19+ years||120 mcg||90 mcg||90 mcg||90 mcg|
Vitamin-Rich Foods to Boost Immune System
The following is a quick and easy chart with some of the better food sources of the best vitamins for immune system health we’ve mentioned above, including vitamin A, vitamin B6, vitamin B9 (folate), vitamin C, vitamin D3, vitamin E, and vitamin K.
Supplements containing these vitamins are often sold in doses that exceed the recommended daily allowances. As a result, a diet of whole foods is a better way to get your vitamins to boost your immunity.
Foods that Boost Your Immune System
|Vitamin A||Sweet potatoes, kale, carrots, spinach, beef liver, romaine lettuce, butter, eggs, winter squash, broccoli, apricots, cantaloupe, mango, sweet red peppers, and tuna|
|Vitamin B6||Turkey breast, grass-fed beef, tuna, chicken breast, sunflower seeds, sesame seeds, chickpeas, amaranth, chickpeas, blackstrap molasses, avocado, pinto beans, and pistachio nuts|
|Vitamin B9 (Folate)||Spinach, broccoli, asparagus, black-eyed peas, beef liver, Brussels sprouts, mustard greens, kidney beans, avocado, romaine lettuce, and oranges|
|Vitamin C||Red peppers, green peppers, black currants, guava, kiwi, oranges, strawberries, papaya, broccoli, parsley, pineapple, grapefruit, cauliflower, mango, and Brussels sprouts|
|Vitamin D3||Halibut, carp, mackerel, eel, salmon, whitefish, swordfish, rainbow trout, sardines, cod liver oil, tuna, eggs, raw milk, maitake mushrooms, and portabella mushrooms|
|Vitamin E||Hazelnuts, almonds, sunflower seeds, mango, avocado, broccoli, spinach, butternut squash, bell peppers, olives, collard greens, Swiss chard, tomatoes, Brussels sprouts, and kiwi fruit|
|Vitamin K||Parsley, dandelion greens, mustard greens, Swiss chard, spring onions, Brussels sprouts, turnip greens, spinach, asparagus, broccoli, sea vegetables, cucumbers, cabbage, strawberries, chicken liver, and cauliflower|
Final Thoughts on Vitamins for Immune System Health
This article featured seven of the best vitamins for immune system health, including vitamin A, vitamin B6, vitamin B9, vitamin C, vitamin D3, vitamin E, and vitamin K. We also explained how each vitamin benefits the immune system, as well as which foods are rich in each vitamin. A vitamin-rich diet will be heavy in vegetables, fruits, and other whole foods.
When you do supplement with vitamins, it is best to choose a high-quality product made from real food sources and free from fillers or toxins. High-quality vitamin supplements are made in a process that allows that body to recognize the vitamins, and this gives you the most immune benefits.
- Skin around Nails Peeling? Vitamin Deficiency and Other Causes
- Vitamin B2 (Riboflavin): Deficiency Symptoms, Benefits, and Food Sources
- Pellagra (Vitamin B3 Deficiency): Causes, Symptoms, and Treatment
- Hypervitaminosis B: Side Effects of Too Much Vitamin B
- Vitamin B12: How It Fights Clogged Arteries and Protects Your Heart
- Folate vs. Folic Acid: What’s the Difference?
- How Much Vitamin C Should You Be Getting Each Day? (Not the RDA)
Article Sources (+)