ISSN: 1223-1533

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Authors: Mihaela Avram, D. Koukoulas, Ada Cean, C. Julean, I. Avram, Florentina Cadariu, S. Olariu

Received for publication: 25th of May, 2013
Revised: 15th of June, 2013

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SUMMARY: (Hide the summary)

Iodine deficiency has multiple adverse effects on growth and development due to inadequate thyroid hormone production that are termed the iodine deficiency disorders (IDD). In nearly all iodine-deficient countries, the best strategy to control IDD is salt iodization, but the possibility of using iodine from algae should be evaluated. We conducted a study on 20 hybrid -NMRI female virgin mice. For 4 weeks they were fed a low iodine diet, containing 25% of mice iodine requirements. The mice presented weight gain (average of 3.55g) and skin lesions which we attributed to hypothyroid induced status. For the following 4 weeks the group was split in two, 10 mice receiving iodine supplement in the form of potassium iodide and the rest receiving iodine from dry Laminaria digitata Algae. The KI group presented weight loss (average of -1.5g), probably due to hyperthyroidism, while the one receiving algae had weight gain (average of 1.1g). All skin lesions, in both groups improved. We concluded that using controlled dose of iodine supplements from algae seems to have fewer side effects than using potassium iodide in iodine deprived animal models, while being as efficient.

Key Words:

iodine deficiency, potassium iodide, algae




Iodine  deficiency  has  multiple adverse  effects on growth and  development   due  to inadequate thyroid hormone production that are termed the iodine deficiency disorders (IDD). IDD remains the most common cause of preventable mental impairment worldwide.  In nearly all iodine-deficient countries, the best strategy  to control IDD is salt iodization, one of the most cost-effective ways to contribute to economic  and social development.[1] When salt iodization is not possible, iodine supplements can be targeted  to vulnerable groups. Introduction  of iodized salt to regions of chronic  IDD may  transiently increase the incidence of thyroid disorders. Taking into consideration the way non iodine deficient  population naturally  have their daily iodine  intake  from diet the possibility of using molecular iodine from sea food should be  evaluated,  as  it may be  more  physiological  than adding potassium iodide to salt.



We formed one lot of 20 hybrid -NMRI female virgin mice subjects aged 8 weeks and one control lot of 5 hybrid  -NMRI female  virgin  mice, same  age.  The experiment was done respecting the European rights of laboratory   animals and   it  took place   in  constant temperature conditions: 21±1oC, with a light cycle of 12 hours per day. 
The experiment  had two  parts:  4 weeks of iodine deficiency followed by  4  weeks   of  iodine supplementation. 
The study lot was fed low iodine diet .The feeding formula (Table 1) was prepared using as a start point Dr Astwood’s  nr. 30 diet [2]. This diet provides 50% (100 ìg iodine /kg) of necessary iodine for mice. We added the necessary  micro nutrients  to the original  formula  to prevent the operation of other diet deficiencies besides iodine. The very low iodine diet was made by combining the special feeding formula with a drinking solution  of sodium perchlorate (400mg/100ml).  This diet provides 50% (100 1g iodine /kg) of necessary iodine for mice. The sodium perchlorate used additionally reduced the iodine intake by 50%[3] By this method the mice received 25% of their recommended iodine intake. The control group received regular mice food and normal drinking water. 
For the iodine supplement of iodine deficient mice we prepared two separated feeding formulas knowing that the iodine necessary for mice is 200 1g iodine /kg nutrient and we aimed an iodine supplementation of 500 1g iodine /kg .

The iodine deficient group was divided into 2 groups: 
10  mice receiving   feeding formula enriched   with potassium iodine and 10 mice receiving feeding formula enriched with algae powder. The control group continued the regular mice diet. All mice received tap water. 
The first iodine rich feeding formula was made using the feeding  formula  prepared  for the first part of experiment   and   adding potassium   iodine 2,7g/kg nutrient.  That way we managed to imitate the iodine supplementation using sodium or potassium iodine from cooking salt that Romanian population receives. 
The second feeding formula was achieved by adding an edible alga into the nutrient made at the first part of the experiment. This way we wanted to imitate the iodine intake of populations with high algae consumption,  like Japan.

We used the Laminaria digitata Algae (Fig 1), a brown specimen that grows in oceans and seas. It belongs to Phaeophyceae    species of  Laminarisaceae    family, Laminaria type. It is used in fresh salads in Japan and China and dried in food preparation. It contains 440 1g iodine /100g .[4]We  used 114 g of powder algae for a kilogram of nutrient.

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Table 1. Low iodine feeding formula


Fig. 1. Dry Laminaria digitata Algae

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All mice were weighted every week and the skin and fur were attentively examined.



After 4 weeks of iodine insufficiency we observed that the mice put on more weight  than the control group, probably due to the hypothyroidism state induced. After reintroduction  of iodine  in the diet the  group  which received KI supplement  had weight  loss, probably due to the hyperthyroidism induced. The lot that received algae supplement   had weight gain, although not as important as the control group. (Table 2, 3, 4)

All mice from the study lot presented skin lesions (eritematous, dry skin patches), the fur became gray and matte, with areas of alopecia. (Fig.2)The mice from the control group presented white, shiny, thick fur. After 4 weeks  of iodine  supplement,  all  mice, no  difference between   KI  and  algae  supplement,   had  the lesions healing.(Fig.3)



Mice receiving a low iodine diet presented signs of hypothyroidism (weight gain, skin lesions) compared to the control group. After reintroducing iodine in the diet, the mice receiving KI had weight loss, compared to the control group and to  the group receiving algae supplement, probably due to  the  induction of hyperthyroidism.  All skin lesions healed, regardless of the way iodine was introduced in the diet. Algae seem to have fewer side effects than KI in iodine deprived mice.


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Table 2. Weight gain in iodine deprived mice and after receiving KI.


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Table 3. Weight gain in iodine deprived mice and after receiving algae.


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Table 4. Weight gain in control group mice.


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Fig. 2. Skin and fur lesions after 4 weeks of low iodine diet


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Fig. 3. Healing skin and fur lesions after iodine supplement.


Studies  were done  to evaluate  supplements  of inorganic iodine salts or algae containing high iodine in pigs. Meat products with a higher iodine content can be produced through feeding animals with a diet supplemented with iodine. This may help to improve daily iodine intake and to control iodine deficiency disorders (IDD) in man. It is suggested that the carry-over of iodine through feeding pigs with an algae-supplemented feed could be beneficial to both the control of IDD and the improvement of pig production. [5]

Most countries  use salt iodization to prevent  IDD. However, salt elevates blood pressure, which is the most important cause for 62% of strokes and 49% of coronary heart diseases[7].  Reducing salt intake has become a global  trend  to decrease  the risk of cardiovascular diseases. Seaweed could be useful to remedy dietary iodine deficiency without the side effect of hypertension. Seaweed consumption has been shown to lower blood pressure as revealed in the studies of Bocanegra [8], Fitzgerald [9], and Wada [10].

We point out the fact that we controlled algae intake in the experiment, as ingesting higher quantities could lead to serious side effects. Algae and other iodine rich food should not be eaten indiscriminately. For consumer health, the World Health Organization set a provisional maximum tolerable daily intake of 1.0 mg iodine/d (0.017 mg/kg body weight) from all sources[11]. Iodine concentration in food needs to  be monitored for consumer health, and this is carried out in many other countries. The European Union has  not issued  any regulation on maximum permissible iodine levels in algae food products.  France has set a limit of 5 mg/kg dry matter for iodine in edible seaweeds[12].  The Federal Institute for Risk Assessment  in Germany warned that dry algae food products with more than 20 mg/kg dry weight might damage health [13]. Iodine-induced toxic effects through consumption of kelp-containing tea have been reported by Müssig  [14]. Crawford reported serious thyroid dysfunction in those who  consume soy milks enriched with kombu in Australia. [15]



Using  controlled  dose  of iodine  supplements  from algae  seems  to have  fewer side  effects  than using potassium iodide in iodine deprived animal models, while being as efficient.



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Correspondence to:
Avram Mihaela, MD, PhD ( First Clinic of Surgery, Timișoara County Hospital, 10 Iosif Bulbuca St., 300736