Zum Iodbedarf und zur Iodversorgung der Haus- und Nutztiere und des Menschen

Grimminger, Susan Pia To the iodine requirements and the iodine
status of the companion and farm animals and the human beings. This
literatur work is about the iodine requirements and the iodine
supply of companion and farm animals as well as the human. For
humans and animals alike iodine is an essential trace element that
is of vital physiological importance as the major component of all
thyroid hormones. Iodine deficiency is worldwide one of the most
common malnutrition and health problems, affecting approximately
1.6 billion people. The most common and devastating consequences of
iodine deficiency are increased perinatal death and mental
retardation. The iodine requirements in general are depending on
the age, the stage of development and the metabolism of the
individual. For humans it ranges from 40 to 130 µg for children up
to 260 µg for nursing mothers. Similary growth, reproduction and
lactation, as well as dietary factors like goitrous supstances in
animal feed influence the physiological iodine requirements of
domestic animals. In relation to their body weight dogs and cats
have a much higher demand of iodine than humans. The National
Research Council states for dogs a daily intake of 52.5 µg iodine/
MJ metabolizable energy and for cats a daily intake of 0.55 µg
iodine/ kcal metabolizable energy as sufficient. A horse is more
sensitive to iodine than other animals. 0.1 – 0.6 mg iodine per
kilogram fodder satisfy the daily need. For poultry the
recommendations for iodine intake vary depending on the development
and achievement between 0.3 and 1.0 mg iodine per kilogram fodder.
In many countries in the world the supply of iodine of the
population is still insufficient. The WHO resolution of 1990 that
set the goal to remedy the iodine deficiencies by the year 2000
could not be realized, yet. The WHO reports in a current
publication that in Europe alone a total of 40 million children do
not get a sufficient supply of iodine. There is however a distinct
global trend of improvement in the supply of iodine due to the
increased acceptance of iodized salt in private homes and the food
industry. Still an ideal supply of iodine can not be ensured in all
areas and in all circumstances. Especially pregnant and nursing
women and their unborn or newborn face a high risk of diseases
caused by a lack of iodine. To evaluate the state of iodine supply
of a population there are a various clinical and biochemical
methods available. The most reliable, cheapest and fastest
indicator is the urinary excretion of iodine. Other methods include
sonographic determination of the thyroid volume, struma prevalence,
measurement of thyreoglobulin concentration and the concentration
of TSH on newborn. The assessment of iodine supply of domestic
animals is difficult as there is no acknowledged clinical
parameter. Studies show that urinary iodine excretion under
clinical aspects is suited well to evaluate the iodine supply of
dogs, cats and horses. Various research demonstrates that domestic
animals are subject to latent iodine deficiency with regional
distinctions just like in human medicine. Due to the common
practice of feeding fodder that is enriched with iodine or mineral
additives iodine deficiency rarely occurs. More common is a slight
iodine overload. Fighting iodine deficiency and diseases caused by
iodine deficiencies several prophylactic actions have proved
themselves to be effective. Usage of iodine salt when preparing
meals in private households and in the food industry is the method
of choice to remedy iodine deficiencies. Adding iodine to the
feedingstuffs of farm animals can increase the iodine content in
food of animal origin. The iodine content in table salt is set to
15 – 25 mg/kg by law. This is calculated such that even if all food
would be prepared with iodized salt, no overdose would occur. The
risk of absorbing absorbing excessive amounts of iodine by way of
food is minimal while the consequences of iodine deficiency could
prove to be catastrophic. The fear of an overdose with iodine in
nutrition in the public is not justified. It is important to make
differences between the physiological demand in the range of
microgram and high doses of iodine intake in the range of milligram
and gram via iodized drugs. The use of iodized mineral mixtures in
the feeding of farm animals is controlled by the German feedstuff
law (maximum levels: 4, 20 and 10 mg iodine/ kg feed for horses,
fish or all other animals).