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Friday, 29 November 2013

Vitamin C Supplements - Should We?

I am not a fan of supplements. Instead I prefer to promote having a healthy balanced nutrition from whole food sources. Some people may benefit from food supplementation under medical supervision if they have a medical condition that requires it. I do feel that too many people just take too many supplements without realising what it is they are taking, why they are taking them, and the effects that the supplements have on the body. 

In this blog I’m going to take a quick look at vitamin and mineral supplements and in particular vitamin C. 

We can get all the vitamins and minerals we need from a healthy diet from whole food sources. Even for athletes supplementation for these is not really necessary. On a recent sports physiology course Mark Hargreaves, Professor of Physiology at the University of Melbourne said "If you take vitamins and minerals, one daily multi-vit is the most you should take unless under medical supervision." 

Vitamin C has many uses inside the body. It promotes a healthy immune system, increases absorption of iron in plant foods, and helps make collagen for wound healing. Too little vitamin C can lead to a condition known as scurvy. We only need about 90mg a day for the efficient working of our bodies. (Source: University of Melbourne)

This isn’t actually very much. 100g of broccoli will provide this for you, as will a large orange. It is quite simple to get all the vitamin C you need from a diet that contains a little fruit and vegetables.

Looking at further evidence for the uses of vitamin C Dr Nicholas Vardaxis (University of Melbourne) tells us that vitamin C from fruit and vegetable sources (not from supplements) is associated with prevention of lung, breast and colon cancers. He says that the reduced oxidative damage from taking the right amount of vitamin C from fruit and vegetable sources (again, not from supplements) is associated with a lower risk of heart disease, and it may prevent the advancement of age related macular degeneration. This is all achieved from a diet getting you the recommended daily intake of around 90mg a day. 

So why take the supplements for Vitamin C? Many people are of the psychology that “if a little is good for you, then a lot is better”. Unfortunately this isn’t true when it comes to vitamins and minerals. Take too much and it can create toxic conditions in the body.

Yet at this time of year many people supplement their diet with vitamin C pills and powders as it is popular to think that it fights the common cold. Interestingly science says that it does not affect the risk of catching a cold, though may reduce the severity and the length of a cold, presumably by helping the immune system work as it should. 

Vitamin C is a water soluble vitamin, and as such, if we take too much the excess is passed in our urea. Yet the processing of excess vitamin C comes with problems. The European Food Standards Agency (EFSA) state that if you take too much vitamin C then “acute gastrointestinal intolerance (e.g., abdominal distension, flatulence, diarrhoea, transient colic) is the most clearly defined adverse effect”.

In other words, if you take too much vitamin C, welcome to having bad guts. 

How much is too much? The EFSA state that at intakes above 1g/day there is “an increased risk of adverse gastrointestinal effects” and that “acute gastrointestinal effects may occur at higher intakes (3-4 g/day)”. They tell us that taking supplementary vitamin C of up to 1g is “not associated with adverse gastrointestinal effects”. 

To summarise, 90mg/day is all that is required, taking up to 1g/day is probably OK, anything over 1g/day and there is an increased risk of having bad guts. 

I decided to look at some popular supplements of Vitamin C in a pure form. Let’s take a look at Holland and Barrett’s Pure Vitamin C Powder (

They recommend “take 1/4 to 1/2 teaspoonful daily” with ½ teaspoon providing “2,500mg” of vitamin C, which they also say is “3,125%” of the daily recommended allowance. So, with anything over 1g/day increasing your risk of adverse gastrointestinal effects here they are advising you to take 2.5g/day. If you take vitamin C supplementation and suffer from bad guts or even IBS – I wonder if the supplementation is causing this?

Hopefully this has got you thinking a little. In conclusion to this post, I would remind you of Mark Hargreaves quote from earlier:

 "If you take vitamins and minerals, one daily multi-vit is the most you should take unless under medical supervision."

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