Do you have a cold? Or maybe you are concerned about Covid 19 or other winter viruses? Would you like to make your cold shorter or prevent infection altogether? Perhaps you are curious if honey and lemon really is beneficial? Read my can your boost your immunity now with vitamin C this winter to find out science backed information.
There are over 200 viruses which can cause the common cold symptoms including runny nose, congestion, sneezing, sore throat, cough, and sometimes headache, fever and red eyes. Since viruses can’t be treated with antibiotics, there is lots of public interest in finding a treatment.
Vitamin C is important for:
🍋 wound healing
🍋helping to keep cells healthy.
Deficiency of Vitamin C
Vitamin C is a water soluble vitamin. This means that any excess is not stored. Instead it is excreted by your kidneys.
Deficiency of Vitamin C can lead to scurvy with symptoms such as weakness, fatigue, and sore arms and legs. If untreated, this can lead to bleeding gums and additional problems.
However, scurvy is incredibly rare but certain groups of people at at higher risk of developing it:
- on a very restrictive diet with very few or no sources of vitamin C
- eating very little food, often because of an underlying medical concern or intensive therapy
- have a poor diet and smoke
- have a poor diet, and are either pregnant or breastfeeding as your body needs more vitamin C at these times.
- significant digestive concerns including ulcerative colitis, or Crohn’s disease.
Foods Rich in Vitamin C
Foods rich in vitamin C are fruit and vegetables, especially citrus fruits, peppers, berries, broccoli and potatoes. The majority of people eating an unrestricted diet should be able to get all of their vitamin C from their diet, without taking a supplement.
Do Vitamin C Supplements Help to Prevent Viral Infection by the Common Cold?
There are often headlines about vitamin C supplementation for colds. But does it actually work and should we all be supplementing?
A large review of the data from lots of studies was analysed together as part of systematic review, which is one of the most robust forms of scientific evidence. The most rigorous type of this analysis is called a Cochrane Review.
A Cochrane review looked at over 11,000 people who were randomised to received Vitamin C supplements, and found that it did not decrease the likelihood of them getting a cold (Hemilä & Chalker, 2013).
In five trials with nearly 600 participants exposed to short periods of extreme physical stress (including marathon runners and skiers) vitamin C halved the common cold risk)(Hemilä & Chalker, 2013).
Does Vitamin C Supplementation Reduce the Duration of Viral Symptoms?
Ok, so Vitamin C doesn’t prevent you from getting a common cold, but does it shorten the duration of symptoms? The same Cochrane Review, looked at 31 studies, combining 9645 episodes of the common cold. They found that regular supplementation had a modest but consistent effect in reducing the duration of symptoms by 8%.
Does Vitamin C Have Any Other Health Benefits?
There is some evidence that having sufficient levels of vitamin C might improve sugar profile, cholesterol levels, blood pressure and decrease risk of cardiovascular disease. The results from studies are mixed though, but highlight that it is important to have sufficient levels of vitamin C in your diet. From diet alone, it is unlikely that you could overdose on vitamin C. There is emerging evidence that vitamin C could help people with the side effects of chemotherapy, but this is currently still mostly in the settings of trial only, and should be discussed with your oncologist.
While the media love an ‘immune boosting’ headline, in reality boosting your immunity is not something to aim for, since ‘boosted’ or over active immune systems are also referred to as autoimmune diseases. Instead, consider supporting your immune system to function, providing it with the nutrients it needs, in the right quantities.
Summary: Can You Boost Your Immunity Now with Vitamin C?
Sadly you can’t boost your immunity with vitamin C, and neither would you want to. At the moment there isn’t strong evidence for most people to take vitamin C supplements, instead aim to have a diet rich in Vitamin C, with a variety of fruit and vegetables, to ensure you have levels in the normal range. Vitamin C may have a modest effect on reducing the duration of cold symptoms.
Hemilä, H and Chalker, E. Vitamin C for Preventing and Treating the Common Cold. Cochrane Database of Systematic Reviews 200, no. 1 (2013): 442.