HER2 Support Group Forums - View Single Post - Iodine deficiency ! - falling intakes - goitregens

R.B. · 11-01-2013, 03:38 PM

Iodine overload - how much is too much ?

Whilst there appears to be significant amount of material suggesting benefits in some from high iodine intake, possibly in those where there has been historic imbalance, or deficiency, and suggestions that some populations have a high intake, there are equally indications that high iodine intake can have adverse consequences.

Daily recommended intakes are in micro grams rather than milligrams. Is this enough given uncertainties as to the level of iodine blockers and competitors such as bromine in our diet. Clearly some think not, and sadly it appears that many are not even getting the minimum requirements in their diet, and that is before the potential blocking of iodine uptake may inhibit their usage of an already very low intake. http://lpi.oregonstate.edu/infocenter/minerals/iodine/

There is much we do not know, for example exactly how other dietary factors interact with iodine intake. The Japanese whatever their historic intake was got their intake from natural food based sources mainly seaweed which would also have been mineral rich and interestingly likely contained significant amounts of bromine (seaweed contains quite high levels of bromine generally).

Iodine contents of seaweeds vary considerably, and iodine is lost in processing and drying, which makes iodine intake through seaweed a bit of a lottery, and clearly if somebody has a lot of bromine in their system from artificially brominated foods then intuitively a food source potentially rich in bromide may not be ideal (although it is possible some of the bromine will also be lost in processing)

Bromine in foods is more of a problem in the US than UK due to brominated soft drinks and flour; but bromine may be used in other products viz the fumigation of dried foods such as nuts; nuts contain quite high amounts of bromine it appears.

It seems potentially lots of foods are fumigated with bromine. Whilst there may be some restriction on fumigation with bromine in the west with foods being sourced all round the world and complex regulations I suspect sadly the reality is overall we do not know what our food contains.

I have no idea if the relatively high levels of bromine found in nut products is from the soil or fumigation, but would guess it is probably largely from fumigation in the county of origin.

Also as previously mentioned bromine/bromide may be used in the brewing industry. Does it reach the beer; I have not been able to find a definitive answer to the question.

http://www.fao.org/docrep/x5042e/x5042e08.htm "Almost invariably, nuts and shelled nuts are fumigated in the country of origin before export, often with methyl bromide. If more than one fumigation is required after importation, there may be danger of taint and a trial treatment should be made."

Methyl bromide may be particularly well absorbed because it is in an organic form (and differently ? metabolised) - oh dear that raises a whole heap of new questions

- as ever things are rarely straight forward - it appears marine organisms produce it and some will end up in the atmosphere. Some plants including the brassicas produce it in small quantities. Large amounts can kill you and do kill customs officers opening containers. http://en.wikipedia.org/wiki/Bromomethane What effect does the sort of levels found in food have? I have no idea but clearly based on the forgoing a bromine iodine imbalance in the metabolic pathways is a potential health issue.

Back to iodine intake; a Japanese Radiological society paper suggest current intake of iodine was around 1mg with their parents consuming more, but exactly how much we do not know. Higher intakes may be problematic particularly for those with other dietary deficiencies including selenium and other minerals.

The paper below looked at a group of Peace Corp staff who had high iodine intake possibly 50mg a day or more for 32 months. The core conclusion is that those using iodination to decontaminate water need regular medical checks. Interestingly the paper does not recommend that sanitisation of water with iodine should not be used, only that regular checks should take place and particular care should be taken in pregnancy. It is a shame the information is not more comprehensive, and does not look at any longer term implications of high dose iodine intake if any.

Effects of Chronic Iodine Excess in a Cohort of Long-Term American Workers in West Africa

http://jcem.endojournals.org/content/87/12/5499.long

The body of the text contains the following comment; if it means this was the result of examination prior to iodine exposure it adds a further dimension to the results.

There was a high prevalence of goiter among Peace Corps volunteers in this study at baseline in both euthyroid and hypothyroid individuals. . .

Abstracts from text

As the arid climate in Niger results in the daily consumption of 5–9 liters water, the volunteers consumed at least 50 mg iodine daily, which is approximately 300 times the daily U.S. Recommended Dietary Allowance (2). Urinary iodine excretion in this iodine-enriched population ranged from 392–153,780 μg/liter (median, 5,048 μg/liter). Volunteers used the water purification devices described above for up to 32 months.

The findings in this study have significant public health implications. In 1998, an estimated 60,000 iodine resin devices and 300,000 bottles of iodine tablets were sold to U.S. civilians for water disinfection (24). In addition, iodine-based water purification systems are routinely used by the military, in international relief efforts, and by other government-sponsored programs. In this regard we have recently reported that excess iodine ingestion by American astronauts from water treated with iodine for purification in space resulted in a small transient rise in serum TSH values upon return to earth (25). Since 1998, the iodine has been removed from astronauts’ potable water by an anion exchange resin just before the water is consumed, and no rise in serum TSH values has been observed. It is probably inadvisable for pregnant women, individuals with a history or a strong family history of thyroid disease, especially autoimmune thyroid disease, or individuals residing in areas of endemic iodine deficiency to use iodine-based methods of water purification unless extremely careful monitoring of the iodine content is carried out. Any individual anticipating prolonged ingestion of excess amounts of iodine in medications or as a byproduct of a water purification system should see a physician for a baseline physical exam to exclude the presence of preexisting goiter and to measure thyroid function tests and serum thyroid antibody levels to rule out abnormalities. Repeat thyroid function tests should then be repeated at intervals until excess iodine ingestion is eliminated.

11-01-2013, 03:38 PM	#59
R.B. Senior Member Join Date: Mar 2006 Posts: 1,843	Re: Iodine deficiency ! - falling intakes - goitregens - competition bromine and fluo Iodine overload - how much is too much ? Whilst there appears to be significant amount of material suggesting benefits in some from high iodine intake, possibly in those where there has been historic imbalance, or deficiency, and suggestions that some populations have a high intake, there are equally indications that high iodine intake can have adverse consequences. Daily recommended intakes are in micro grams rather than milligrams. Is this enough given uncertainties as to the level of iodine blockers and competitors such as bromine in our diet. Clearly some think not, and sadly it appears that many are not even getting the minimum requirements in their diet, and that is before the potential blocking of iodine uptake may inhibit their usage of an already very low intake. http://lpi.oregonstate.edu/infocenter/minerals/iodine/ There is much we do not know, for example exactly how other dietary factors interact with iodine intake. The Japanese whatever their historic intake was got their intake from natural food based sources mainly seaweed which would also have been mineral rich and interestingly likely contained significant amounts of bromine (seaweed contains quite high levels of bromine generally). Iodine contents of seaweeds vary considerably, and iodine is lost in processing and drying, which makes iodine intake through seaweed a bit of a lottery, and clearly if somebody has a lot of bromine in their system from artificially brominated foods then intuitively a food source potentially rich in bromide may not be ideal (although it is possible some of the bromine will also be lost in processing) Bromine in foods is more of a problem in the US than UK due to brominated soft drinks and flour; but bromine may be used in other products viz the fumigation of dried foods such as nuts; nuts contain quite high amounts of bromine it appears. It seems potentially lots of foods are fumigated with bromine. Whilst there may be some restriction on fumigation with bromine in the west with foods being sourced all round the world and complex regulations I suspect sadly the reality is overall we do not know what our food contains. I have no idea if the relatively high levels of bromine found in nut products is from the soil or fumigation, but would guess it is probably largely from fumigation in the county of origin. Also as previously mentioned bromine/bromide may be used in the brewing industry. Does it reach the beer; I have not been able to find a definitive answer to the question. http://www.fao.org/docrep/x5042e/x5042e08.htm "Almost invariably, nuts and shelled nuts are fumigated in the country of origin before export, often with methyl bromide. If more than one fumigation is required after importation, there may be danger of taint and a trial treatment should be made." Methyl bromide may be particularly well absorbed because it is in an organic form (and differently ? metabolised) - oh dear that raises a whole heap of new questions - as ever things are rarely straight forward - it appears marine organisms produce it and some will end up in the atmosphere. Some plants including the brassicas produce it in small quantities. Large amounts can kill you and do kill customs officers opening containers. http://en.wikipedia.org/wiki/Bromomethane What effect does the sort of levels found in food have? I have no idea but clearly based on the forgoing a bromine iodine imbalance in the metabolic pathways is a potential health issue. Back to iodine intake; a Japanese Radiological society paper suggest current intake of iodine was around 1mg with their parents consuming more, but exactly how much we do not know. Higher intakes may be problematic particularly for those with other dietary deficiencies including selenium and other minerals. The paper below looked at a group of Peace Corp staff who had high iodine intake possibly 50mg a day or more for 32 months. The core conclusion is that those using iodination to decontaminate water need regular medical checks. Interestingly the paper does not recommend that sanitisation of water with iodine should not be used, only that regular checks should take place and particular care should be taken in pregnancy. It is a shame the information is not more comprehensive, and does not look at any longer term implications of high dose iodine intake if any. Effects of Chronic Iodine Excess in a Cohort of Long-Term American Workers in West Africa http://jcem.endojournals.org/content/87/12/5499.long The body of the text contains the following comment; if it means this was the result of examination prior to iodine exposure it adds a further dimension to the results. There was a high prevalence of goiter among Peace Corps volunteers in this study at baseline in both euthyroid and hypothyroid individuals. . . Abstracts from text As the arid climate in Niger results in the daily consumption of 5–9 liters water, the volunteers consumed at least 50 mg iodine daily, which is approximately 300 times the daily U.S. Recommended Dietary Allowance (2). Urinary iodine excretion in this iodine-enriched population ranged from 392–153,780 μg/liter (median, 5,048 μg/liter). Volunteers used the water purification devices described above for up to 32 months. The findings in this study have significant public health implications. In 1998, an estimated 60,000 iodine resin devices and 300,000 bottles of iodine tablets were sold to U.S. civilians for water disinfection (24). In addition, iodine-based water purification systems are routinely used by the military, in international relief efforts, and by other government-sponsored programs. In this regard we have recently reported that excess iodine ingestion by American astronauts from water treated with iodine for purification in space resulted in a small transient rise in serum TSH values upon return to earth (25). Since 1998, the iodine has been removed from astronauts’ potable water by an anion exchange resin just before the water is consumed, and no rise in serum TSH values has been observed. It is probably inadvisable for pregnant women, individuals with a history or a strong family history of thyroid disease, especially autoimmune thyroid disease, or individuals residing in areas of endemic iodine deficiency to use iodine-based methods of water purification unless extremely careful monitoring of the iodine content is carried out. Any individual anticipating prolonged ingestion of excess amounts of iodine in medications or as a byproduct of a water purification system should see a physician for a baseline physical exam to exclude the presence of preexisting goiter and to measure thyroid function tests and serum thyroid antibody levels to rule out abnormalities. Repeat thyroid function tests should then be repeated at intervals until excess iodine ingestion is eliminated. Last edited by R.B.; 11-01-2013 at 04:19 PM..