[Effects of Vitamin C] Is Vitamin C Really Effective in Preventing Cold?

Hello, I am Jinny, a pharmacist.

Vitamin C is such a familiar nutrient to us that it's hard to find anyone who hasn't consumed it at some point. It's a common nutrient found in various vegetables and fruits, multivitamin supplements, and even convenience store beverages and ice creams. Vitamin C is particularly known as a nutrient that's good for preventing colds,

However, there are also many people who wonder, "I consume it because it's supposed to be good for me, but I'm not sure if vitamin C really helps with colds, or exactly how and where it benefits me." So today, we will take a closer look at the actions and benefits of vitamin C when consumed, using scientific research as our guide.

The immune system can be broadly categorized into innate immunity and adaptive immunity. The concept of immunity that we commonly refer to corresponds to adaptive immunity. Adaptive immunity, or acquired immunity, is responsible for recognizing previously encountered antigens (immunological memory) and mounting specific responses upon re-exposure to effectively eliminate those antigens. In this way, adaptive immunity plays a role in enhancing innate immunity.

A review article in Nutrients summarizes the role of vitamin C in the immune system as follows:

According to data presented at the 2020 Korean Diabetes Association, approximately 1 in 7 adults aged 30 and over in South Korea (13.8%) were found to have diabetes. It has become a very common disease among modern people. The major concern with diabetes is that it can lead to various cardiovascular complications, including high blood pressure.

A study published in Hypertension in 2013 investigated the impact of vitamin C intake on vascular health in diabetic patients and reported the following findings:

Not only that, but vitamin C is widely known for its various benefits to the skin. With its strong antioxidant action, it not only inhibits reactive oxygen species that promote aging in the body, but also helps in the production of collagen, a component of the skin, hair, muscles, and more.

Therefore, there have been numerous studies on the beneficial effects of oral vitamin C intake on skin health. According to a study published in 2007 based on data from the UK's National Health and Nutrition Examination Survey, there is a strong correlation between vitamin C intake and skin-related indicators in middle-aged women.

Today, we explored the various benefits that vitamin C can offer, including boosting the immune system. To further investigate the direct relationship between vitamin C and the common cold, you may want to refer to a randomized clinical trial published in 2007 [1]. In this study, vitamin C intake did not have a significant preventive effect on the general population, but it was found to reduce the incidence of colds by over 50% in a group of highly active athletes. Additionally, regular intake of vitamin C by the general population was reported to reduce the duration and severity of colds after they occurred.

[1] Hemilä, H., Chalker, E., & Douglas, B. (2007). Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews.

However, even if it's not exclusively for the purpose of cold prevention and treatment, it's essential to remember that vitamin C is a "critical nutrient" with a triple role in our lives.

I hope you have a healthy day both physically and mentally. This was Jinny.