During this time of national crisis, brought about by the COVID-19 pandemic, there are many key workers in many industries – health & social care, transport, retail, emergency services, council workers to name but a few – who are working hard to keep us well supplied, safe & secure. And we the public must do our bit too. Staying at home & social distancing when outdoors, will reduce our exposure to the Corona virus, but unfortunately will not eliminate the risk completely. So what else can we do? Something which is just as important as reducing our exposure, and is not, in my view, emphasised enough at the moment, is how can we increase our immune resilience to this virus? How can we make our bodies a hostile & unpleasant environment for the virus to take root, if we are exposed?
So let’s put the spotlight on vitamin C – our body’s key worker at times of crisis.
Vitamin C is a water soluble organic compound that occurs naturally in many fruit & vegetables. Vitamins have an important role in virtually all of the many different biochemical & physiological functions of our bodies. With the exception of some vitamin B3 & vitamin D, we cannot make our own vitamins so we have to obtain sufficient amounts in our diet. Because vitamin C is water soluble very little can be stored in the body – unlike vitamins A, D, E & K, which are fat soluble and therefore can be stored. Once ingested, any vitamin C absorbed will be either used or excreted within 4 hours, which means a regular top-up is essential.
Why does the body need vitamin C?
The roles of the different vitamins often overlap & they frequently work in combination, however, the more we learn about vitamin C, the more we realise that it plays such a crucial role in so many of the vital bodily processes that keep us functioning normally.
Vitamin C is necessary for the normal formation of collagen – the most abundant structural protein in the body & responsible for healthy skin, bones, ligaments & tendons as well as the repair of these tissues when they’re injured.
it is also a powerful ant-oxidant, able to neutralise free radicals from environmental or dietary toxins & so reduce cellular DNA damage. Vitamin C aids cellular energy production, supports the normal function of our nervous system and plays an integral part in the absorption of iron.
But it is the immune system where vitamin C has earned its reputation as a key worker and rightly so, particularly at this time of a viral pandemic. In addition to maintaining healthy skin, which is our first defence against infection, Vitamin C assists in the production of white blood cells which protect the body against infection, as well as helping them work more effectively.
Is it true that some animals can make their own vitamin C?
Yes, it’s true, most animals can make their own supply of vitamin C from blood glucose (dogs, cats, goats & cows are examples). Many millions of years ago, our ancestral primates inherited a gene mutation that has continue to be present through evolution so that we humans (as well bats & guinea pigs) lack the final enzyme in the internal vitamin C production line. What’s of significant interest is that those animals that produce their own vitamin C do so at levels far higher than the recommended daily allowance (RDA – see below) for humans and at times of stress – either physical or psychological – will automatically increase production even higher.
So, which foods are rich in vitamin C?
Fortunately there is an abundant natural supply of vitamin C, which is probably why the gene mutation all those year ago didn’t put our ancestors at an evolutionary disadvantage.
A good source of vitamin C is found in citrus fruits, kiwis, pineapple, strawberries, tomatoes, red pepper and even potatoes – providing you leave the skin on!! Vegetables, such as kale, cabbage, broccoli and sprouts are also rich in vitamin C as well as many other important nutrients, of course. Most people can meet their recommended daily allowance by eating fruit and vegetables.
Be aware that the amount of vitamin C in fruit & vegetables will depend the way they are grown, stored & how old they are.
What do you mean by the recommended daily allowance (RDA)?
The recommended daily allowance (RDA) is the average amount of a nutrient needed to meet the basic nutritional requirements of the majority of a healthy group of individuals. It will vary with age & between males & females. They were first produced in the 1950’s and are viewed every 5-10 years, although it it accepted the the scientific evidence on which they’re based is scanty, at best. Interestingly, Vitamin C RDA has changed little over the last 30 years despite detrimental changes in food production and storage, and the increasing incidence of chronic disease including cancer. So if you’re happy with your health being based on the average basic requirements, then stick with the RDA, but if you wish to thrive, not just survive, then much higher levels are likely to be optimal.
How much vitamin C should I really have each day?
The recommended daily allowance (RDA) for vitamin C is approximately 1mg/kg body weight per day, so between 60-90mg/day for an adult. It’s the highest RDA of all vitamins, highlighting the important role this vitamin plays in keeping us healthy. As mentioned above, RDA is more than likely to understate the amount of vitamin C required for optimal health and a more appropriate amount would be at least twice the RDA (120-150mg/day) and potentially as much as 500-700mg/day.
Vitamin C toxicity from overdose is rare, especially in otherwise healthy individuals, and if it occurs tends to be in the form of gastric upset & diarrhoea. Because this compound is water soluble, it is excreted from the body via the kidneys, and some studies have linked high amounts of vitamin C with an increase risk of kidney stones in susceptible individuals.
Are vitamin C supplements worth considering?
There are two options if we wish to increase our daily intake of vitamin C.
One is to increase the amount of vitamin C rich fruit & vegetables we eat each day & preferably with each meal. In practice this can be a challenge -particularly as we never really know how much vitamin C there is in an orange or portion of Kale. Furthermore, the majority of vitamin C enters the blood stream by being absorbed through the small intestine. This process not only requires energy and other nutrients such as sodium, it is also rate limited so the more we ingest, the less is absorbed.
However, most people looking to increase their daily vitamin C levels do so using dietary supplements. This has two main advantages – firstly, you know exactly how much vitamin C you are actually taking, and secondly you can take advantage of a much more efficient route of absorption. Vitamin C can also be absorbed directly into our blood stream though the lining of our mouth (buccal absorption). This process is entirely passive, so requires no energy & has no maximum limit. So by choosing a good quality, high strength supplement that is taken by allowing it to dissolve in the mouth, it is possible to take advantage of the body’s more efficient absorption process and maximise your daily intake.
What are the benefits of taking a higher day amount of Vitamin C?
As we understand more fully the many bodily functions that require vitamin C, there are an increasing number of studies examining the health benefits of daily amount higher than the RDA. Higher daly levels of vitamin C intake have been associated with a lowing of the risk for many cancers including oesophagus, oral cavity, stomach, pancreas, cervix, rectum and breast, as well as a reduction in risk of heart disease, cataracts and even the risk of premature death!! And that’s an impressive list by anyone’s standards!!
Can vitamin C cure the common cold, or help with COVID-19?
Even though vitamin C can definitely support our immune system, and has been shown to improve serum levels of Interferon, which is a powerful anti-viral, there is no evidence that vitamin C can cure the common cold. There are studies, however, suggesting that people who take high levels of vitamin C on a regular basis experience a reduced level of symptoms for a shorter period of time.
Vitamin C has been shown to be effective in treating many different viral infections, including SARS pneumonia. and there is real hope that when combined with other essential vitamins and minerals, it may be able to effectively prevent and treat COVID-19, although at this stage the relative benefits of different doses and route of administration including intravenously, need further study.
The bottom line …..
Vitamin C is a vital ingredient in our daily diet as it is essential for many of our body’s important functions – bone & joint health, skin & wound healing, nerve & brain health and of course immune health. We cannot make it ourselves, or store it to any significant degree, so we must consume an adequate amount on a regular basis throughout the day. To avoid deficiency we need at least 1mg/Kg body weight/day, but if we want to thrive, not just survive, if we want to move towards optimal health not average health, then taking several times RDA or even hight may be required especially if the body is emotionally or physically stressed.
If considering vitamin C supplements, then choose a reputable company with high quality ingredients that are absorbed by dissolving or chewing in the mouth, rather than swallowing.