Key Nutrients to Support Your Immune Response Heading into Winter

Winter brings shorter days and less sunlight. You may also spend more time indoors, making it harder to stick with your usual exercise and sleep routines. These and other factors can affect immune health, making it especially important to get enough of the nutrients your immune system needs.

Chief among them are vitamins D and C, zinc, and selenium, each of which plays a role in immune health. Getting enough vitamin D for immune support, along with these other nutrients, helps immune cells develop, communicate, and protect your body.*

Vitamin D and Immune Function

Vitamin D is a powerhouse when it comes to immune health. This multitasking vitamin does more than support strong bones. It also helps keep your immune system working properly.*

Many immune cells have receptors that allow them to respond to vitamin D. Getting enough vitamin D for immune balance helps these cells recognize potential threats and communicate with one another. Vitamin D also helps your body make protective proteins, such as cathelicidin, which support normal immune defenses and a balanced immune response.*

Getting enough vitamin D can be a challenge, especially in winter. Your skin makes vitamin D when exposed to sunlight, but shorter days, weaker sunlight, and more time indoors can limit how much your body makes.

Food can help, but few foods naturally contain much vitamin D. Fatty fish such as salmon and trout are among the richest sources, while egg yolks provide smaller amounts. Fortified foods, including milk, plant-based beverages, and cereals, can also help, but the amount of added vitamin D varies by product. Some contain added sugars, so check the Nutrition Facts label and ingredient list.

These challenges may help explain why some people don’t get enough vitamin D. In one national survey of U.S. adults, about 42% were deficient in vitamin D.

When food and sunlight aren’t enough, a vitamin D supplement may help. Supplements come in two main forms: D2 (ergocalciferol) and D3 (cholecalciferol). A systematic review and meta-analysis of randomized clinical trials found that vitamin D3 supplementation was more effective than D2 supplementation at raising vitamin D status in the blood.

Choosing a vitamin D3 supplement can help you meet your needs and support healthy immune function.* Because vitamin D is fat-soluble, taking it with a meal that contains some fat may help your body absorb it.

Vitamin C Provides Antioxidant and Immune Support*

Vitamin C plays an important role in keeping your immune system functioning at its best. It supports immune cell function and helps strengthen your body’s natural defenses.*

During normal immune activity, your body produces unstable molecules called free radicals. When these molecules accumulate, they can damage immune cells and interfere with their ability to function properly. As an antioxidant, vitamin C helps neutralize free radicals and protect immune cells, supporting a healthy immune response.*

Because your body cannot make or store large amounts of vitamin C, you need a regular supply from foods such as citrus fruits, strawberries, kiwi, bell peppers, broccoli, and Brussels sprouts. Many of these foods also contain bioflavonoids, beneficial plant compounds that work alongside vitamin C.

If you don’t eat these foods regularly or need higher amounts of vitamin C for immune support, a supplement can help you meet your needs.* Some vitamin C supplements also contain bioflavonoids, which may provide added antioxidant status support.*

Zinc Helps Support a Healthy Immune Response*

Zinc adds another layer of immune support.* This essential mineral helps immune cells develop and respond to everyday environmental exposures.* It also supports the growth and repair of cells that form natural protective barriers in your body, including those in your gut and lungs.*

Getting enough zinc matters because a deficiency can weaken your immune defenses. People who eat little or no meat or seafood, or who have trouble absorbing zinc because of certain digestive conditions or medications, may be at greater risk of deficiency.

Your body cannot store large amounts of zinc, so you need a regular supply from foods such as oysters and other seafood, beef, poultry, eggs, dairy products, beans, and nuts.

A daily zinc supplement can help you meet your needs when your diet falls short.* However, taking too much zinc over time can interfere with copper absorption. A qualified health-care practitioner can help you choose an appropriate amount.

Selenium Supports Immune and Antioxidant Status*

Selenium may be less familiar than vitamins C and D or zinc, but this essential mineral plays an important role in immune health.

Your body uses selenium to make proteins that help protect immune cells from damage and support their normal function. One example is glutathione peroxidase, an enzyme that helps control free radicals. Selenium also helps maintain a balanced immune response to everyday challenges.*

Seafood, meat, eggs, and nuts are good sources of selenium, with Brazil nuts providing especially high amounts. Just one or two Brazil nuts can provide the recommended daily amount of 55 mcg for most adults. If your diet falls short, a supplement can help you meet your needs.* However, more isn’t necessarily better. The upper limit for adults is 400 mcg per day, and regularly getting too much selenium can be harmful. A qualified health-care practitioner can help you choose an appropriate amount.

Build Your Winter Immune Routine

Supporting your immune health doesn’t require a major change to your daily routine. Regular walks, enough sleep, and meals containing a variety of fruits, vegetables, and protein-rich foods can all help.

When food and sunlight don’t meet your nutritional needs, supplements can help fill the gaps.* A vitamin D supplement for daily use may help you meet your needs when you get less sunlight.* A daily vitamin C supplement, along with zinc and selenium when needed, can provide additional immune support.*

Because nutritional needs vary from person to person, work with a qualified health-care practitioner when considering dietary supplements. A practitioner can help you determine whether vitamin D, vitamin C, zinc, or selenium supplements are appropriate for your individual needs and health goals.*

Key Takeaways

• Vitamin D helps immune cells recognize potential threats and supports a balanced immune response.* A supplement can help you get enough vitamin D for overall wellness when winter sunlight is limited.*
• Vitamin C supports immune cell function and helps protect these cells from the normal accumulation of free radicals.*
• Zinc helps immune cells develop and respond to everyday challenges.* It also supports natural protective barriers in the body, including those in the gut and lungs.*
• Selenium supports a balanced immune response and helps protect immune cells from damage.* Getting enough is important, but more isn’t necessarily better.*
• A varied diet, regular exercise, enough sleep, and supplements when needed can help support immune health throughout fall and winter.*

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.