Top Natural Immune Boosters for Cold & Flu Season: Vitamins, Herbs, and Supplements

Happy fall! Can you believe it's here already? While I am still wishing there were hot, sunny days, I am looking at the beautiful fall colors and focusing on being present and accepting What IS.

We all know that with fall comes the colds and flus that we're hoping to ward off! Whether you’re trying to stay healthy or looking for natural ways to recover more quickly when something hits, it’s the perfect time to give your immune system some extra love.

I am a firm believer in using safe, toxin free products for everyday ailments. These are a few of my favorite things for keeping your immune system strong through fall and winter. Start on them now and you may find you are one of the lucky few who stay well this year! As a former full-time holistic and integrative nutritionist, I love sharing simple, natural ways to support your health.

Ripe Elberberries

Vitamin D3

This power vitamin (really, it's a hormone precursor) can often reduce your risk of getting sick in the first place when taken properly. Only a blood test can help you figure out exactly how much you need to take, but for most adults, the daily dose is a minimum of 2,000 IU and very often up to 5,000 IU a day. The best way to get Vitamin D is from the sun, but in the winter, vitamin D levels plummet, and the immune system along with it. Vitamin D3 plays a critical role in the killer T cell response, and is therefore a major regulator of a healthy immune response.

Kids: A maintenance dose for children is 35 IU per bound of body weight.

Dosing: 2,000-5,000 IU per day

Zinc

Zinc is my first choice for defending against the viruses that cause the common cold and seasonal flu. (Fun fact: it’s also one mineral many of us tend to be low in!) Zinc is an immune-supportive mineral found in beef, lamb, oysters, and — in smaller amounts — pumpkin seeds, cashews, and beans. Adequate zinc levels help your immune system function properly, and studies show it may help reduce the duration and severity of colds when taken at the first sign of symptoms.

A respected medical clearinghouse in the U.K. (Cochrane Database of Systematic Reviews) found that zinc can be more effective than chicken soup when it comes to shortening the common cold!

Dosing:

• Children 4–8 yrs: 5 mg/day

• Children 9–13 yrs: 8 mg/day

• Teens 14–18 yrs: 9–11 mg/day

For everyday immune support, many adults take around 15 mg per day. When you feel like something might be “coming on,” you can safely increase to up to 40 mg per day for a short time — that’s the upper limit for adults. Zinc lozenges are especially helpful when taken within the first 24 hours of symptoms.

Vitamin C

Vitamin C is another immune-supporting powerhouse! It packs a strong punch when it comes to helping your body fight illness. Vitamin C supports immune cell function, acts as a powerful antioxidant, and can help reduce the duration and severity of colds when taken regularly or at the first sign of infection.

Because it’s water-soluble, your body flushes out what it doesn’t need — making it much harder to take too much compared to fat-soluble vitamins like Vitamin D. It’s a great one to keep on hand, especially through cold and flu season.

Some studies — including those using intravenous (IV) Vitamin C in clinical settings — have explored its potential benefits for recovery from severe infections. However, these are specialized treatments that should only be done under medical supervision.

Dosing:

• Kids: Buffered ascorbic acid (gentler on the stomach), 250–500 mg up to three times daily with meals.

• Adults: 500–1,000 mg one to three times daily, depending on need and tolerance. During illness, some people increase temporarily (up to 2,000 mg three times per day), but large doses can cause loose stools — a good sign to scale back.

Turmeric/Curcumin

Studies show that curcumin, the active ingredient in turmeric, plays an important role in various aspects of strengthening the immune system. Curcumin helps modulate inflammation in the body and supports overall immune balance.

Because curcumin is not easily absorbed on its own, it’s best taken with black pepper extract (piperine) or a fat-containing meal to enhance absorption.

Dosing for immune and anti-inflammatory support:

• Standardized curcumin extract (95% curcuminoids): 500–1,000 mg per day, divided into 1–2 doses.

Elderberry Syrup

This age old traditional remedy is packed with antioxidants and helps supports and strengthen the immune system. It’s known for its ability to shorten the duration of colds and flu when taken at the first sign of symptoms.

Both the flowers and berries have been used in traditional herbal medicine to help relieve nasal congestion, soothe upset tummies, and ease gas. Elderberry also has gentle diuretic and detoxifying properties, and it’s naturally rich in vitamins A and C and bioflavonoids, making it an excellent immune tonic for daily use during cold and flu season.

Daily dosing:

• Adults: 1 tablespoon (15 mL) once daily

• Children: 1 teaspoon (5 mL) once daily

• At the first sign of illness:

  • Adults: 1 tablespoon every 2–3 hours (up to 4 times daily)

  • Children: 1 teaspoon every 2–3 hours (up to 4 times daily)

Omega 3 Essential Fatty Acids

Omega-3s are one of those nutrients I love for so many reasons — yes, they support heart and brain health, but they’re also really helpful for our immune system. They help calm chronic inflammation, which can otherwise make our immune response less effective, support our white blood cells so they do their job properly, and even help our body “switch off” inflammation once it’s done its job, which keeps tissue damage to a minimum during illness. I get mine from fatty fish like salmon and sardines, and also from chia, flax, and walnuts.

Dosing: Most adults do well with 1–3 grams of combined EPA and DHA per day, and kids can usually get 250–500 mg per day, depending on age.

Ashwagandha

A powerful immune-supporting adaptogen, ashwagandha helps your body reboot from stress while also supporting a healthy immune response. It’s one of my favorite herbs for kids, who can easily get run down from sleepovers, sports, tests, recitals, and the constant stream of social and academic pressures — often without even realizing it. Ashwagandha gently supports their resilience, helping them stay balanced and energized even when life keeps coming at them 24/7.

Dosing: Kids: 150–250 mg/day; Adults: 300–500 mg/day, once or twice daily.