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 (http://www.hollandandbarrett.com/pages/product_detail.asp?pid=119&prodid=489&cid=68)
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."
