Iron is probably the best known of all the essential
minerals found in the human body; and this is not
surprising since it is vital for the formation of hundreds
of the proteins and enzymes on which health depends. But
iron deficiency is nevertheless one of the commonest
nutritional problems seen worldwide and is surprisingly
prevalent even in the affluent West, particularly amongst
vegetarians and those who consume little or no red meat.
Unfortunately the solution is not so straightforward as a
simple program of supplementation. The problem is that the
body does not easily get rid of excess iron which may
therefore tend to accumulate in the body. Unused molecules
of iron appear to be particularly prone to oxidation and
"free radicalisation" and may contribute to the age-related
degeneration of the organism associated with free radicals.
Excess iron is believed to be a particular risk factor for
the oxidation of the low density lipids (LDL), or "bad
cholesterol" recognised as a precursor of atherosclerosis,
or hardening of the arteries, a major premature killer in
the West.
Sufficient iron, however, remains vital for human health;
and its best known and most important function is in the
formation of haemoglobin, the protein in red blood cells
which carries oxygen around the body. Around two-thirds of
the iron in the body is believed to be used for this
purpose. Not surprisingly, since a lack of iron means an
insufficiency of oxygen being delivered to the body's
cells, fatigue is the principal and best known deficiency
symptom, reflected in a significantly reduced ability to
tolerate physical exercise or activity; but it can also
lead to headaches, dizziness, shortage of breath and even
angina in extreme cases.
But it's not just the red blood cells which depend on iron.
White blood cells, too, and therefore the health of the
immune system, are heavily reliant on an adequate supply to
combat bacterial and viral infections; and it is worth
noting that lowered immune system responsiveness may be
observed as a symptom of inadequate iron intake well before
the onset of outright anaemia.
Iron is also an essential constituent of a number of the
catalase and peroxidase anti-oxidant enzymes which are
particularly important in neutralising hydrogen peroxide,
perhaps the most dangerous of all free radicals.
Iron has important interactions with other vital nutrients.
A deficiency of vitamin A has been shown to increase the
effects of anaemia and the deficiency condition responds
better to treatment with iron when combined with vitamin A
supplementation. Good levels of vitamin C likewise appear
to assist in the body's absorption of iron from food
sources. It is also particularly important to ensure
adequate intakes of copper and zinc if iron is to be
properly metabolised.
The best food sources of iron are red meat, poultry and
fish, although wholegrains, egg yolks and green vegetables
also provide a certain amount. However, the consumption of
calcium rich foods at the same meal is believed to reduce
the absorption of iron, as is the consumption of refined
carbohydrate. Taking tea or coffee soon after a meal will
also reduce iron absorption. So-called "heme" iron is
the form found in the haemoglobin content of meat, poultry
and fish. It is the most desirable form of the mineral
because although it is readily absorbed by the body it does
not accumulate within it. Unfortunately, however, heme
iron commonly supplies only about one-third of the total
obtained from the diet. Regard therefore needs to be had
to the amount of non-heme iron consumed which may build up
in the body over time, with possibly adverse consequences
for health. The US Food and Nutrition Board (FNB)
Recommended Dietary Allowance (RDA) for iron is 8 mg a day
for adult males and 11 mg for male adolescents. The
allowance for females is higher to allow for losses during
menstruation and is set at 15 mg a day for adolescents and
18 mg for adults. The requirement for iron rises
dramatically during pregnancy at any age, the RDA being set
at 27 mg. Post-menopause, however, the RDA for women is
the same as for men.
Research in fact indicates that many adult males and post
menopausal women are likely to exceed the RDAs by consuming
up to 18 mg per day of iron from their normal diet, but
this could well be a deficiency intake for individuals
during adolescence, pregnancy, menstruation and those
undertaking intensive exercise regimes, all of which may
increase the body's need for iron.
Careful regard therefore needs always to be had to
individual diet and requirements, but iron supplements
should in any case be taken only as part of a comprehensive
multi-vitamin and multi-mineral preparation. It is also
especially important to note that any iron supplementation
is strongly contra-indicated for young children, except
under close medical supervision, because of a high risk of
severe toxicity.
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Steve Smith is a freelance copywriter specialising in
direct marketing and with a particular interest in health
products. Find out more at
http://www.sisyphuspublicationsonline.com/LiquidNutrition/In
formation.htm
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