As the cold and flu season approaches, many people start looking for ways to bolster their immune systems to ward off illness. While washing hands regularly, getting enough sleep, and staying hydrated are all important factors, the right supplements can provide your body with the necessary nutrients to help fend off infections. In this comprehensive guide, we’ll discuss the top supplements to take during the cold and flu season, backed by research, along with healthy foods that naturally contain these nutrients.
1. Vitamin C: The Classic Immune Booster
Why It’s Beneficial
Vitamin C is one of the most well-known supplements when it comes to immune support. It plays a crucial role in supporting various cellular functions of both the innate and adaptive immune systems. According to a 2017 review published in Nutrients, vitamin C supplementation was shown to reduce the duration of common cold symptoms and, in some cases, the severity.
Vitamin C works by supporting the epithelial barrier function against pathogens, and promoting the scavenging of oxidants produced by immune cells during inflammation. It’s also necessary for the production of white blood cells, which are essential for fighting off infections.
Foods Rich in Vitamin C
- Oranges and other citrus fruits
- Bell peppers
- Strawberries
- Broccoli
- Spinach
- Kiwi
How to Supplement
For those looking to boost their vitamin C intake, supplementation in doses of 200 mg to 1000 mg per day has been shown to be effective in supporting immune health.
2. Zinc: Essential for Immune Function
Why It’s Beneficial
Zinc is another powerhouse when it comes to immune defense. It helps the immune system function properly by supporting the development and function of immune cells like neutrophils, macrophages, and natural killer cells. Zinc is also critical for the proper functioning of enzymes that play a role in immune signaling.
According to a meta-analysis published in The Journal of Infectious Diseases in 2017, zinc supplementation, especially when taken at the onset of cold symptoms, can reduce the duration of colds by up to 33%. This trace mineral is particularly effective in preventing viruses from replicating in the body.
Foods Rich in Zinc
- Oysters (the highest source of zinc)
- Beef and lamb
- Pumpkin seeds
- Chickpeas
- Lentils
- Cashews
How to Supplement
Zinc supplements typically range from 15 mg to 30 mg per day. However, it’s important not to over-supplement with zinc, as taking more than 40 mg daily can interfere with copper absorption and may lead to side effects like nausea.
3. Vitamin D: The Sunshine Vitamin
Why It’s Beneficial
Vitamin D plays a critical role in immune regulation. It enhances the pathogen-fighting effects of monocytes and macrophages—key components of the body’s immune defense system—and decreases inflammation. Vitamin D deficiency has been linked to an increased susceptibility to infection, particularly respiratory infections like the flu.
A 2020 study published in The BMJ found that regular vitamin D supplementation reduced the risk of acute respiratory infections, especially in individuals with low baseline levels of vitamin D.
Foods Rich in Vitamin D
- Fatty fish like salmon and mackerel
- Cod liver oil
- Egg yolks
- Fortified foods such as milk, orange juice, and cereals
How to Supplement
During the winter months, when sunlight exposure is limited, it can be difficult to get enough vitamin D through diet alone. Supplementation with 1000 IU to 4000 IU of vitamin D3 daily is generally recommended for maintaining optimal levels.
4. Probiotics: Supporting Gut Health
Why They’re Beneficial
A healthy gut is key to a robust immune system, as approximately 70% of the immune system resides in the gut. Probiotics are beneficial bacteria that help maintain the balance of microorganisms in the digestive tract. This balance is crucial because an imbalance (known as dysbiosis) can impair immune function and increase susceptibility to infection.
Several studies, including a 2019 review in Frontiers in Immunology, have shown that probiotics may reduce the incidence and duration of upper respiratory infections by modulating the immune response.
Foods Rich in Probiotics
- Yogurt with live cultures
- Kefir
- Sauerkraut
- Kimchi
- Miso
- Kombucha
How to Supplement
Probiotic supplements containing strains like Lactobacillus and Bifidobacterium have been shown to improve immune health. A daily dose of 1 billion to 10 billion CFUs (colony-forming units) is recommended to maintain gut balance and support the immune system during cold and flu season.
5. Elderberry: A Natural Immune Enhancer
Why It’s Beneficial
Elderberry has long been used as a natural remedy for colds and flu. Rich in antioxidants and flavonoids, elderberry extract may help reduce the severity and duration of cold and flu symptoms. A 2016 study in Nutrients found that elderberry extract can reduce the duration of flu symptoms by up to four days and reduce symptom severity in air travelers.
Elderberry’s active compounds are believed to inhibit the entry of viruses into cells and support immune responses against pathogens.
Foods Rich in Elderberry
While elderberry supplements are popular, it’s also possible to consume elderberry in the form of:
- Elderberry syrup
- Elderberry tea
- Elderberry gummies
How to Supplement
Elderberry extract is commonly available in syrup or capsule form, and a typical dosage for adults is 500 mg to 1000 mg daily during cold and flu season.
6. Echinacea: Herbal Immune Support
Why It’s Beneficial
Echinacea is a herb that has been used for centuries to treat colds, flu, and infections. Studies have shown that it may help boost immune function by increasing the production of white blood cells. A meta-analysis published in The Lancet Infectious Diseases found that echinacea could reduce the risk of developing a cold by 58% and shorten its duration by 1.4 days.
How to Supplement
Echinacea is available in various forms, including capsules, teas, and tinctures. For best results, it’s recommended to start echinacea at the first sign of cold symptoms. Typical dosages range from 300 mg to 500 mg, taken three times daily.
7. Garlic: A Natural Antibiotic
Why It’s Beneficial
Garlic has antimicrobial and immune-boosting properties, thanks to its active compound, allicin. A 2014 study published in The Journal of Nutrition found that garlic supplementation reduced the severity of cold and flu symptoms and shortened the duration of illness.
Garlic has been used traditionally to fight infections and has been shown to stimulate the immune system by enhancing the production of immune cells and acting as a natural antibiotic.
Foods Rich in Garlic
- Fresh garlic cloves
- Garlic supplements (aged garlic extract)
How to Supplement
For those who don’t enjoy raw garlic, supplements are available in capsules. A common dosage is 600 mg to 1200 mg daily.
8. Quercetin: A Potent Antioxidant
Why It’s Beneficial
Quercetin is a powerful flavonoid that has antioxidant, anti-inflammatory, and antiviral properties. It has been shown to inhibit the replication of viruses and enhance the immune system’s response to infections. A 2020 study published in Frontiers in Immunology found that quercetin supplementation reduced the risk of upper respiratory infections, especially when combined with vitamin C.
Foods Rich in Quercetin
- Apples
- Onions
- Berries
- Green tea
- Red wine
- Leafy greens
How to Supplement
Quercetin is often taken in doses of 500 mg to 1000 mg daily, often combined with vitamin C for enhanced absorption and effectiveness.
The Importance of a Healthy Diet During Cold and Flu Season
While supplements can play a significant role in boosting your immune system, maintaining a healthy diet is equally important during cold and flu season. Focus on incorporating whole, nutrient-dense foods that provide essential vitamins, minerals, and antioxidants. Here are some dietary tips:
- Eat a rainbow of fruits and vegetables: Rich in vitamins, minerals, and antioxidants, fruits and vegetables like bell peppers, spinach, berries, and sweet potatoes support immune function.
- Include healthy fats: Omega-3 fatty acids found in fish like salmon, flaxseeds, and walnuts help reduce inflammation and support immune health.
- Hydrate: Staying hydrated is critical, especially during the winter months when dry indoor air can dehydrate you more quickly.
- Limit processed foods: Foods high in sugar and refined carbohydrates can suppress the immune system and increase inflammation.
Stay Healthy This Season: Boost Immunity with the Right Supplements
As the cold and flu season approaches, taking the right supplements can provide your immune system with the boost it needs to keep you healthy. Vitamin C, zinc, vitamin D, probiotics, elderberry, echinacea, garlic, and quercetin are all backed by scientific research for their immune-supporting properties. In addition to supplementation, focus on eating a balanced, nutrient-dense diet to give your body the best chance of fighting off illness this season.