Now is as good a time as any to start boosting your immune system in preparation for the inevitable slew of annual bugs and viruses.
Where better to start than by topping up with one of nature’s favourite remedies: Vitamin C.
Not only is this one of the easiest ways to keep you protected at this time of year, you might just find that other niggling joint and skin problems start to disappear.
Vitamin C (ascorbic acid)
Out of all the vitamins this is probably the most often used, but why do we reach for vitamin C when the nights draw in and there’s a chill in the air - and how does it work?
Vitamin C has been extensively researched and for good reason, it has a number of important roles in the body which can help to keep you fit and well throughout the autumn and winter.
Not only is vitamin C an outstanding antioxidant it is also one of the most important water soluble vitamins.
It is essential for a whole range of functions, with virtually all cells in the body depending on it.
As well as supporting the immune system, vitamin C is necessary for:
- protein metabolism
- wound healing and tissue repair
- collagen synthesis
- energy production
- increasing iron absorption in the gut
- its role as a co-factor involved in neurotransmitter synthesis
- protection from free radical damage
Support the immune system with vitamin C
Vitamin C deficiency is associated with a supressed immune system.
This is not an unreasonable assumption to make given that several cells of the immune system can accumulate vitamin C and need this vital vitamin to perform their tasks.
In fact scientific research has identified that vitamin C concentrations in the blood plasma and white blood cells decline during infections and stress.
It is thought that one of the mechanisms by which vitamin C improves the function of our immune system is by increasing the activity of anti-microbial and natural killer cell activities, as well as having direct antioxidant capacities offering our cells protection against free radical damage generated during the inflammatory response.
Studies have shown that vitamin C aids the action of neutrophils, a type of white blood cell used by the immune system as the first line of defence against invading bacteria and viruses.
Vitamin C also influences the proliferation of T-cells which are responsible for either killing off infected targets or releasing enzymes to destroy them.
T-cells do this by producing an army of cytokines as well as helping B cells to produce the molecules needed to control inflammation.
In addition to this vitamin C has been found to block the pathways that lead to elimination of the T-cells that are so important for attacking infection.
Large doses of vitamin C have also been found to assist in the production of substances called interferons which play an important role in activating the immune system against viruses.
Further evidence of vitamin C’s key role in immunity comes from a comprehensive review of the available research carried out by the Cochrane Collaboration.
Their investigations confirmed that vitamin C consumption does help to reduce the duration and severity of colds.
Vitamin C, immunity and the skin
The skin plays an important role in immunity because it provides a strong barrier against potentially damaging environmental substances.
It is also subject to a constant barrage of insults from microbes, so without its protective shield we would quickly fall prey to bacteria and fall ill.
Vitamin C is vital for the production of collagen, which is the most abundant protein in the body.
Collagen makes up more mass than all other proteins combined and forms connective tissue which holds the skin together.
It also helps to support the blood vessels needed to supply oxygen and nutrients to the skin allowing it to fulfil its protective functions.
The body makes collagen continuously to maintain and repair connective tissue and is dependent on a regular and adequate supply of ascorbic acid.
Because this important vitamin acts as a co-factor for the synthesise of collagen if this process is interrupted it can have a detrimental effect on skin health and function.
How much vitamin C do you need?
This is a vital nutrient that cannot be synthesised by the body and so it is essential we find it in our food.
Making sure your diet is filled with an abundance of fruit and vegetables is the best way to keep your vitamin C levels topped up plus you benefit from a range of other vitamins, minerals, flavonoids and antioxidants that play an important role in ensuring your immune system is functioning as it should.
Aim to eat from 5 to 10 portions of fruit and vegetables a day including vitamin C rich foods such as: broccoli, citrus fruits, sweet potatoes, berries, peppers, kiwi, Brussel sprouts, guava, papaya, kale, cabbage, cauliflower, garlic, cantaloupe melons.
For those who want to supplement with vitamin C the recommended daily intake of vitamin C for adults is only 75 mg to 120 mg, with an additional 35 mg for smokers.
The upper tolerable level is 2000mg for adults due to the fact that some people experience some gastric discomfort and diarrhoea when taking very high doses of vitamin C.
Higher therapeutic levels may be appropriate for some conditions but this should only be administered under the advice of a qualified health practitioner.
Although it isn’t possible to live in a totally bug free environment, you can take steps to keep your immune system in tip-top shape so it’s ready for anything.
The good thing is - it’s never too late to improve your diet and start making changes!
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- Abdel-Wahab O et al. Restoration of TET2 Function Blocks Aberrant Self-Renewal and Leukaemia Progression. Cell, 2017.
- Akhilender Naidu K. Vitamin C in human health and disease is still a mystery ? An overview. Nutrition Journal 2003, 2:7.
- Cass H and English J. The Collagen Connection. Nutrition Review 2003.
- Harrison FE, May JM. Vitamin C Function in the Brain: Vital Role of the Ascorbate Transporter (SVCT2). Free radical biology & medicine. 2009;46 (6): 719-730.
- Kuo SM (2013) The Multifaceted Biological Roles of Vitamin C. J Nutr Food Sci 3: 231
- Leliefeld PHC, Koenderman L, Pillay J. How Neutrophils Shape Adaptive Immune Responses. Frontiers in Immunology. 2015;6:471.
- McRae MP. Vitamin C supplementation lowers serum low-density lipoprotein cholesterol and triglycerides: a meta-analysis of 13 randomized controlled trials. Journal of Chiropractic Medicine. 2008;7(2):48-58.
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