A healthy immune system depends on adequate nutrition, including a range of vitamins and minerals that help immune cells and other parts of the body’s defense system function normally.
Vitamin C, vitamin B6 and vitamin E are among the nutrients involved in immune function, but they are not the only ones. The National Institutes of Health says adequate amounts of vitamins A, B6, B12, C, D and E, along with folate, copper, iron, magnesium, selenium and zinc, are important for normal immune function.
For most people, getting these nutrients from a varied diet is preferable to taking supplements without a specific need. The NIH says that when a person is not deficient in a particular nutrient, increasing vitamin and mineral intake through supplements generally does not prevent infections or help people recover from them faster.
Vitamin C
Vitamin C is a water-soluble vitamin that helps the immune system function properly. It also acts as an antioxidant and is needed to produce collagen, a protein involved in wound healing.
Citrus fruits such as oranges and grapefruit are well-known sources. Strawberries, broccoli and other vegetables can also contribute to vitamin C intake.
A deficiency can impair normal immune function, although severe vitamin C deficiency is uncommon in people who have access to a varied diet. The recommended amount varies according to age and sex.
Vitamin B6
Vitamin B6 is involved in more than 100 enzyme reactions in the body and also plays a role in immune function.
It occurs naturally in foods including poultry, fish, potatoes and other starchy vegetables, as well as some fruits. Chickpeas are another source.
The amount needed depends on age and life stage. Most people can obtain adequate vitamin B6 through food, although certain medical conditions and alcohol dependence can increase the risk of deficiency.
Vitamin E
Vitamin E is a fat-soluble nutrient and antioxidant that helps protect cells and supports immune function. It is found in foods including nuts, seeds, vegetable oils and green leafy vegetables.
Vitamin E deficiency is rare in otherwise healthy people. Evidence that vitamin E supplements prevent respiratory infections is mixed, and high doses can carry risks, including an increased risk of bleeding.
For that reason, getting vitamin E from food is generally preferable unless a health professional recommends supplementation.
A varied diet matters
Immune health is not dependent on one vitamin or a particular food. A varied diet that supplies adequate vitamins, minerals, protein and other nutrients supports normal immune function.
Fruits and vegetables can provide vitamin C, beta-carotene and other nutrients. Nuts, seeds and vegetable oils provide vitamin E, while foods such as poultry, fish, potatoes and chickpeas provide vitamin B6.
Zinc also plays an important role in immune function. Other nutrients, including vitamins A and D, vitamin B12, folate, iron and selenium, are also involved in maintaining the body’s immune defenses.
The U.S. Centers for Disease Control and Prevention has reported that many children and adolescents do not meet recommended fruit and vegetable intake. In U.S. data cited by the agency, foods high in added sugars and solid fats accounted for about 40% of daily calories among children and adolescents ages 2 to 18.
A balanced diet is therefore more useful for supporting immune health than focusing on individual supplements. People who have a diagnosed deficiency or a medical condition affecting nutrient absorption may need supplements under the guidance of a health professional.
The key point is that vitamins support the immune system as part of overall nutrition. They are not a substitute for a varied diet, and taking more than the body needs does not necessarily provide greater protection against infection.
