So you feel a cold coming on: should you stock up on vitamin C?, by Brittany Kralik, BGSU Intern
We live in a day and age where there is no time to spare for overcoming a common cold. Our schedules are busy and we simply do not have time to devote days towards overcoming an illness. Instead, we stock up on vitamin C supplements the moment we feel a cold coming on. The intention of this commonality is understandable: use an easy to ingest supplement in order to reduce the amount of time that the illness keeps us in bed. But is mega-dosing vitamin C worth the money and effort? Does taking 1,000 mg of vitamin C daily, if not multiple times daily, really help to prevent or shorten the length of the common cold? Let’s find out.
For starters, what is vitamin C and why is it the go-to for illness prevention?
Vitamin C is an antioxidant that works to relieve oxidative stress within the body, which is why vitamin C is thought to help alleviate the common cold. When a body experiences an infection or an illness, it causes the release of reactive oxidizing agents in the body. The role of vitamin C is to protect cells against the harmful actions of those oxidizing agents. Essentially, vitamin C works as a shield or barrier against harmful substances during illness. Additionally, vitamin C is also thought to play a role in the actual immune system. High levels of vitamin C have been found in white blood cells, which indicates that vitamin C plays a functional role in those protective cells.
Vitamin C is water soluble meaning that if the body has excess amounts of it, it will usually be excreted. Vitamin C can be found naturally in many foods including oranges or orange juice, bell peppers, grapefruit or grapefruit juice, and tomatoes. The recommended daily allowance (RDA) for adults over the age of 18 is 90 mg for males and 75 mg for females.
Does vitamin C actually have an impact on colds?
Researchers published a study in 2013 that determined taking 200 mg of vitamin C daily, which exceeds the RDA by over 200%, decreased the risk of getting a cold in half. However, this finding was significant only in populations that are extremely active, such as marathon runners. The study concluded that taking 200 mg of vitamin C daily did not lower the risk of getting a cold in the general population.
It was determined, however, that taking 200 mg of vitamin C daily reduced the length of common colds by 8% in adults and 14% in children. This reduction in length equals out to about one day of illness, meaning that taking 200 mg of vitamin daily may reduce the length of your cold by one day.
It is recommended to consume vitamin C daily in order to experience the full benefits of the nutrient. More specifically, it is recommended to obtain vitamin C through food sources rather than dietary supplements because food is the preferred fuel for our body. Eating your sources of vitamin C ensures that you are also consuming other vitamins and minerals, as well as, fiber and energy.
What about the products that contain thousands of milligrams of vitamin C? Unfortunately, the body cannot absorb and store all of that vitamin C for later use. Any amount above 400 mg is excreted through the urine. In other words, the 1,000 mg dietary supplements might not be worth your money.
Make sure to get enough vitamin C daily even before any signs of a cold start to appear. This will help the body maximize the benefits of the vitamin. In terms of mega-dosing vitamin C at the first sign of a cold: it may reduce the length of your illness by one day but your body will likely excrete most of the supplement you consume.
Alternatively, a healthy diet accompanied by exercise is a great way to prevent illness.
Brittany is a Wood County native who studied dietetics during her undergraduate career at Bowling Green State University. She is currently completing her dietetic internship while working on receiving her Master’s of Food and Nutrition from BGSU. After becoming a registered dietitian, Brittany plans to pursue a PhD with hopes to work in the research and development process of sustainable food products. Outside of the academic setting, she enjoys working out, trying new coffee shops, and supporting locally owned restaurants and businesses.”
Carr AC, Lykkesfeldt J. Vitamin c in health and disease. Nutrients. 2017. ISBN 978-3-03897-030-9
Vitamin C fact sheet for health professionals. NIH. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/#h3. Accessed on: 2020 Jan 28.
Can vitamin C prevent a cold? Harvard Health Letter. 2017 Jan. https://www.health.harvard.edu/cold-and-flu/can-vitamin-c-prevent-a-cold. Accessed on: 2020 Jan 28.