Essential Nutrients for Stronger Immunity

Winter has arrived, bringing with it a heightened risk of respiratory infections and illnesses. It feels like everywhere we turn, there's an abundance of cold and flu remedies promising relief from those dreaded symptoms. But what if we could take action earlier? What if, before falling ill, we proactively build our immune system? Just as we would take precautions when we know a storm is coming, shouldn't we treat our bodies with the same care and foresight?

At Sfera, we embrace a different approach. Rather than relying solely on reactive solutions, we emphasise the importance of proactively strengthening our immune system before illness strikes. By fortifying our bodies with the right nutrients, we can empower our immune systems to effectively combat the challenges of the winter season. Now is the perfect time to prioritise nourishing ourselves from within, reinforcing our immune defences, and maintaining optimal health throughout this season.

Among these key nutrients are Vitamin C, Vitamin D, and Zinc, a powerful trio that plays a vital role in maintaining robust immune function, forming a strong foundation upon which a healthy immune defence can be built.

Vitamin C, also known as ascorbic acid, is renowned for its immune-boosting properties.  Multiple studies have indicated that Vitamin C supplementation can effectively reduce the duration and severity of the common cold (Hemilä & Chalker, 2013; Bucher & White, 2016). This essential nutrient plays a critical role in supporting various immune system functions, including the stimulation of immune cell production and activity (Carr, 2017). By incorporating Vitamin C into our daily routine, we can strengthen our immune system and enhance its ability to fight off infections and maintain overall health.

One of the joys of winter is spending more time indoors, getting cosy and warm. However, there's a downside to this - we get less exposure to sunlight, which means we're missing out on the "sunshine vitamin" - Vitamin D. Our skin produces Vitamin D when it's exposed to sunlight. A local study conducted last year revealed that up to 22% of people in South Africa become Vitamin D deficient during the winter months (Middelkoop, et al., 2022). Low levels of Vitamin D have been linked to an increased incidence of the common cold. In fact, a significant study analysing 10 clinical trials found that Vitamin D can actually reduce the chances of getting influenza (Zhu, et al., 2022). At Sfera, we've formulated our Vitamin D supplement with MCT oil, which aids in the absorption of Vitamin D, making it a more effective choice for supplementation.

Zinc is involved in the development and activation of immune cells, the production of antibodies, and the regulation of inflammation (Wessels & Maywald, 2017). Adequate levels of zinc are essential for the proper functioning of the immune system. Certain groups, such as the elderly, vegetarians, and vegans, are particularly at risk of zinc deficiency, with an estimated one in every three elderly persons suffering from zinc deficiency (Wessels, Maywald & Rink, 2021). Low levels of zinc have been associated with immune dysfunction, while supplementing with zinc can shorten the duration of colds by almost 33% (Wang, Win & Pang, 2020). To ensure a strong immune system, it is crucial to include zinc-rich foods such as meat, shellfish, legumes, nuts, and seeds in our diets. However, supplementation can bridge the gap and ensure optimal zinc levels for immune support. Sfera Zinc contains essential co-factors with a highly bio-available form of Zinc for effective supplementation.

To harness the immune-boosting benefits of this power trio, it is important to incorporate them into our daily routines. As the winter season looms ahead, prioritizing the health of our immune systems becomes paramount. By incorporating the power trio of vitamin C, vitamin D, and zinc into our daily routines, we can provide our bodies with the essential nutrients they need to bolster our defences.  So, give your immune system the support it deserves and embrace a proactive approach to keeping healthy this winter.


Bucher, A., & White, N. (2016). Vitamin C in the Prevention and Treatment of the Common Cold. American journal of lifestyle medicine10(3), 181–183. 

Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients9(11), 1211. 

Dawson-Hughes, B., Harris, S. S., Lichtenstein, A. H., Dolnikowski, G., Palermo, N. J., & Rasmussen, H. (2015). Dietary fat increases vitamin D-3 absorption. Journal of the Academy of Nutrition and Dietetics115(2), 225–230. 

Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. The Cochrane database of systematic reviews2013(1), CD000980. 

Middelkoop, K., Walker, N., Stewart, J., Delport, C., Jolliffe, D. A., Nuttall, J., Coussens, A. K., Naude, C. E., Tang, J. C. Y., Fraser, W. D., Wilkinson, R. J., Bekker, L. G., & Martineau, A. R. (2022). Prevalence and Determinants of Vitamin D Deficiency in 1825 Cape Town Primary Schoolchildren: A Cross-Sectional Study. Nutrients14(6), 1263. 

Rondanelli, M., Miccono, A., Lamburghini, S., Avanzato, I., Riva, A., Allegrini, P., Faliva, M. A., Peroni, G., Nichetti, M., & Perna, S. (2018). Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and Echinacea … to Prevent or Treat Common Colds. Evidence-based complementary and alternative medicine : eCAM2018, 5813095. 

Wang, M. X., Win, S. S., & Pang, J. (2020). Zinc Supplementation Reduces Common Cold Duration among Healthy Adults: A Systematic Review of Randomized Controlled Trials with Micronutrients Supplementation. The American journal of tropical medicine and hygiene103(1), 86–99. 

Wessels, I., Fischer, H. J., & Rink, L. (2021). Dietary and Physiological Effects of Zinc on the Immune System. Annual review of nutrition41, 133–175. 

Wessels, I., Maywald, M., & Rink, L. (2017). Zinc as a Gatekeeper of Immune Function. Nutrients9(12), 1286.

Zhu, Z., Zhu, X., Gu, L., Zhan, Y., Chen, L., & Li, X. (2022). Association Between Vitamin D and Influenza: Meta-Analysis and Systematic Review of Randomized Controlled Trials. Frontiers in nutrition8, 799709.