Boosting your immune system and vitamin C
Vitamin C is a water soluble antioxidant found in fresh fruits and vegetables. There is no doubt that vitamin C is of great benefit for the immune system. It helps fight free radicals and is involved in the formation and maintenance of connective tissue. Research indicates it may also protect against cancer.
Recently, I have heard of many people taking large doses of vitamin C to ‘boost’ their immunity during this pandemic. Although it is generally regarded as safe. This overloading may be problematic because we don’t absorb large amounts of the most comon forms in supplements very well.
There is also evidence that large doses of vitamin C may distort some blood tests and interfere with medications, such as blood thinning drugs like warfarin. It is therefore important your doctor is aware of any supplements you are taking.
Are you making expensive pee with your vitamin C supplement?
Bioavailbility of some supplements is as little as 14-30% and this can decrease with intakes above 200mg. The NHS recommended minimum for dietary vitamin C, to prevent scurvy, is just 40mg.
Adequate amounts of vitamin C can be obtained from just five servings of foods such as kiwi, berries, broccoli and citrus fruits. However, it is not stored in the body for long so regular intakes are necessary.
The medical trials you may have read about in the media are still ongoing and have all involved intravenous vitamin C in large doses. Supplements made with the most comon forms of vitamin C that contain over 500mg may have a laxitive effect.
High doses can cause nausea, heartburn, gastric upset, wind and also diarrhoea! Our body can only absorb a certain amount of vitamin C at a time when we take it orally. Any excess is just excreted in urine, making expensive pee!
Why do we need vitamin C?
Vitamin C is an antioxidant that has an important role in supporting our health and immunity. It supports immune function by up regulating immune cells. Vitamin C is also associated with the prevention of respiritory tract infections. It may help to increase recovery time by reducing the duration of the infection.
Vitamin C has anti-microbial properties and may inhibit fungi and virus replication. It supports healthy energy production and has been shown to be protective against cardiovascular disease and hypertension.
The anti-oxidant capability of vitamin C helps support blood vessels and inflammation modulation. It plays an important role in skin health, including supporting the formation of the skin barrier and collegen. Vitamin C also provides antioxidant protection against UV photo-damage to skin.
Boosting your immune system with food
I don’t normally use the phrase ‘boosting your immune system’, I call it immune support, but it is a commonly used term for the purpose of this blog. I normally advise clients to focus on food first, but there are times when a supplement may be advised.
Food provides our body with the synergestic nutrients it needs for health. A healthy diet can support our immune system and aid recovery from illness such as viruses and infections.
How can you increase your vitamin C?
Try to eat a rainbow of fruit and vegetables that are naturally rich in vitamin C. Vegetables such as sweet potatoes, bell peppers, watercress, spinach, broccoli and fruits such as berries, pinapple, kiwi and citrus fruits. I normally advise my clients to aim for 6 portions of vegetables, including leafy greens, and up to 3 portions of fruit daily.
Aim for as much variety as possible to support your gut health and ‘boost’ immune function. Colourful fruit and vegetables are not just delicious. They also contain polyphenols and flavanoids which feed the beneficial bacteria important for our gut health. A healthy gut will help strengthen your immune system so that it can work efficiently.
Do you still want a vitamin C supplement?
If you don’t eat enough fruit and veg on a regular basis and you want to supplement vitamin C there are some forms that are better absorbed. Liposomal forms normally absorb better, but tend to be the most expensive.
The other option is look for a timed release capsule that also contains bioflavanoids to aid absorption. A daily dose of 200 – 1000 mg is a good place to start. This can be increased at first signs of cold or flu symptoms when there is an increased need for vitamin C.
Nutritional supplements may not be suitable for some people and may intefer with medications. If you want to find out more about using vitamin C and other ways to ‘boost’ your immune system contact a Nutritional Therapist for personalised advice.
References & Bibliography
Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia-Reperfusion Injury
Vitamin C Can Shorten theLength of Stay in the ICU: A Meta-Analysis
The Nutrient Bible, 9th ed. Henry Osiecki