Tried and True Supplements for the Flu Season

Are you worried about getting sick during these harsh times? Many of us are in the same boat and are wondering how to be proactive this season.

As you know, eating a healthy diet, getting enough sleep and exercising regularly is imperative to keep a healthy immune system strong. With these basic foundations in place, you can add on specific nutrients that your body needs to keep your immune system balanced and ready to fight off infections. These supplements contain ingredients with proven benefits to aid the immune system.

Supplements for the Flu Season

Vitamin D

As the cold weather approaches, we spend less time outdoors. Vitamin D is produced in our skin cells when they are exposed to sun rays – so it comes as no surprise that vitamin D deficiency is the most prevalent from October to April. Vitamin D deficiency is extremely common and is associated with increased inflammation and deregulation of the immune system.[1] It is an essential part of keeping a balanced immune system that is ready to fight!

Did you know that many of our immune cells have vitamin D receptors? This means that vitamin D can directly activate and increase the production of immune cells.[2]

We suggest trying an emulsified vitamin D3 supplement, as it is the most absorbable. 

Vitamin C

One of the most popular vitamins for the cold and flu season is vitamin C. Why? Supplementing vitamin C improves immune cell activities so that the natural killer cells can get rid of pathogens in the body.[3] This powerful antioxidant helps alert immune cells to sites of infections and enhances their ability to kill microbes.[4]

We suggest trying a fat-soluble, liposomal form of vitamin C because it will stay in your body longer than other vitamin C supplements. Vitamin C is naturally water-soluble and will be excreted in your urine throughout the day. Liposomal vitamin C ensures you are using up all the vitamin C in the supplement!


This mineral is needed for the growth, development, and maintenance of immune cells.[5] Zinc deficiency is common, as it cannot be stored in the body and has to be consumed daily to ensure adequate amounts. Zinc deficiency has been shown to impair immunity, delay wound healing, and increase inflammation in the body. [6] A deficiency in zinc can cause unfavorable changes to the thymus, the organ that produces immune cells. Luckily, the supplementation of zinc is able to reverse those changes and strengthen the signaling pathways of immune cells![7]

Taking too much zinc is unlikely to cause symptoms, however, it can hide a copper deficiency. To be safe, it is advised to take a copper-zinc formula when supplementing the long-term.[6]


These berries have traditionally been used to address cold and flu symptoms. Elderberries contain high levels of anthocyanins, which have antiviral activities and are able to boost immune function.[8] They are a popular home remedy for upper respiratory symptoms from influenza or colds, such as sinus congestion, sore throat, cough or fever. Elderberry supplementation has been shown to reduce the duration and severity of these symptoms.[8] It can also be taken as a preventative measure or at the onset of symptoms for the best results. 

We suggest choosing elderberry that is commercially prepared and is standardized, to provide an effective option. This syrup from Suro Organic is a staple in our cupboards!

When should you start supplementing for the flu season? 

Keep in mind that the effects of supplements take time. Start today and build up your immunity sooner rather than later! 


Grace Tien is dietetics and holistic nutrition grad. She creates sustainable, delicious meal plans to help clients with their health goals. Grace specializes in nutrition for healthy periods, you can find out more at on Instagram.  


  1. Sassi, F., Tamone, C., & D'Amelio, P. (2018). Vitamin D: Nutrient, Hormone, and Immunomodulator. Nutrients, 10(11), 1656.

  2. Prietl, B., Treiber, G., Pieber, T. R., & Amrein, K. (2013). Vitamin D and immune function. Nutrients, 5(7), 2502–2521.

  3. Wintergerst, E. S., Maggini, S., & Hornig, D. H. (2006). Immune-enhancing role of vitamin C and zinc and effect on clinical conditions. Annals of nutrition & metabolism, 50(2), 85–94.

  4. Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211.

  5. Read, S. A., Obeid, S., Ahlenstiel, C., & Ahlenstiel, G. (2019). The Role of Zinc in Antiviral Immunity. Advances in nutrition (Bethesda, Md.), 10(4), 696–710.

  6. Maywald, M., Wessels, I., & Rink, L. (2017). Zinc Signals and Immunity. International journal of molecular sciences, 18(10), 2222.

  7. Maares, M., & Haase, H. (2016). Zinc and immunity: An essential interrelation. Archives of biochemistry and biophysics, 611, 58–65.

Hawkins, J., Baker, C., Cherry, L., & Dunne, E. (2019). Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trials. Complementary therapies in medicine, 42, 361–365.