Iodine Nutrition in Pregnancy
Australian studies show brain impairment due to iodine
deficiency in the womb is not reversible
Hannah Devlin,
Science
Editor, wrote in the Times on 1 May 2013 that scientists in Tasmania have found babies whose mothers have low
levels of iodine during pregnancy have worse literacy skills in childhood. At
nine years old, children who did not receive enough iodine in the womb
performed worse than their peers in reading and spelling tests. Very importantly
the scientists also reported:-
“Although the
participants’ diet was fortified with iodine during childhood, later
supplementation was not enough to reverse the impact of the deficiency during
the mother’s pregnancy.”
Maybe it will now be better appreciated by the Department of Health in the UK that mild iodine deficiency of the
mother (i.e. a deficiency that is not severe enough to result in cretinism in
the baby, as in the Tasmania study) can have significant and lifetime effects.
Can we expect advice in the UK about iodine for women of reproductive age being
brought into line with WHO recommendations in the near future? I suspect not.
Department of Health advice and SACN position paper on
Iodine
However there are signs at
last that the Department of Health and the Scientific Advisory Committee on Nutrition (SACN) that advises it are coming to terms with the problem
of iodine deficiency in young women and with the implications for foetal brain
development.
The NHS website www.nhs.uk from November 2012 contains the following
advice about iodine (search for iodine) :-
Adults need 0.14mg
of iodine a day. Most people should be able to get all the iodine they
need by eating a varied and balanced diet.
However, if you are
pregnant, you may need to take iodine supplements. This is because an iodine
deficiency during pregnancy can harm the development of your baby.
If you take iodine
supplements, do not take too much because this could be harmful.
Taking 0.5mg
or less a day of iodine supplements is unlikely to cause any harm.
The SACN is in the late stages of producing a position
paper on iodine nutrition. Gestation of the paper has been prolonged. It has
been discussed in February and June 2012 and February 2013 and will again be considered
in June 2013. It is presumed that it will then be finalised and presented to
the Department of Health and will be
posted on www.sacn.gov.uk (where the draft
paper and discussions can be read).
SACN
seem to have accepted, somewhat reluctantly, that urinary iodine levels are
worthy of investigation in the UK and it is likely that their use will be
included somehow with the Nutritional Diet and Nutrition Survey; it is the NDNS
which is based on food analysis combined with information on “typical” diets
that has been traditionally used to estimate, by calculation, the adequacy of
diets of different sectors of the population.
The
SACN would seem to have fully appreciated the importance of iodine for the
foetus. It is hoped that it will not take many years before women of reproductive
age are advised to ensure they have adequate iodine intakes ideally in their
diet but if necessary by iodine supplements. It is not possible to envisage
that widespread iodisation of salt or of bread would ever be possible in the
UK. Too many people would object that their rights/freedom would be being
impinged by supplementing a foodstuff.
Unfortunately
it seems that the inevitable requests for further funds for research may impede
unequivocal advice being given for iodine supplementation before and during
pregnancy. On the one hand the research workers do not want to give the
impression that they know enough of the answers and thereby need no more funds
and on the other the bureaucrats are likely to be happy not to have to make a
decision.
Although
the scientists working on iodine deficiency disorders across the world have
known for many years that foetal brain damage caused by the deficiency is
irreversible it would seem that scientists in the UK are not prepared to use
the word irreversible because it is likely to frighten people. Perhaps we, the
research workers and the Department of Health need scaring into action.
Meanwhile
please pass this on to all friends and relatives for whom it might it be relevant.
Vic
Shorrocks 9th May 2013
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