49 replies to this topic

[Skötkonung]

BBC: "A study involving more than 700 teenage girls at nine UK centres found more than two-thirds had a deficiency."

The researchers suggest drinking more milk (something I personally do not favor). Other top food sources include:

• Fish - The iodine content of fish is quite variable. In general, marine fish have more iodine than fresh water fish, and a significant part of the iodine is in the head of the fish (where the thyroid is). Here are some typical amounts for some common fish, in mcg/100g: Cod (110), Haddock (250), Herring (29), Mackerel (140), Sardines (29), Tuna (30), Atlantic Salmon (76), Rainbow Trout (13). Here are a few ranges to give you a sense of the variability of iodine in fish (mg/100g): Haddock (60 – 920), Pollack (23 – 266), Cod (18 – 1270).
• Sea vegetables - Iodine levels in seaweed are quite variable, depending primarily on the type of seaweed. Kelp has the highest amount of iodine, with some kelp granules having 8165 mcg/gm. Most Kelp or Kombu has about 2500 mcg/gm. Other common seaweeds are much lower; for example, Nori (16 mcg/gm), Wakame (32 mcg/gm), Dulse (72 mcg/gm), Hijiki (629 mcg/gm). Iodine content is reduced by storage (e.g., in paper bags or open to the air) and cooking. Most of the iodine in seaweed comes in the form of iodide, but it varies depending on the type of seaweed. Absorption of the iodine from seaweed is variable. Seaweed contains lots of stuff besides iodine, some may be useful (e.g., other minerals) and some may be harmful (e.g., goitrogens like bromide and various chemicals like mercury contaminants). Large amounts of seaweed may be problematic.
• Other Dairy Products
• Eggs - The Office of Dietary Supplements estimates that one large egg contains about 24 mcg of iodine.
• Meat - The iodine in meat depends on the iodine in the feed. Numerous studies have been done experimenting with different amounts of iodine in the feed. Here are some ranges. I suspect that most meat will have iodine levels toward the low end of the range. In mcg/kg: Beef heart (24 – 434), Liver (40 – 356), Kidney (32 – 532). Another study on beef, giving the mean iodine levels in mcg/kg: Muscle (173), Liver (70), Kidney (61).
• Shellfish - Shellfish is variable, but some typical amounts of iodine (mcg/100 g) are Oysters (60), Mussels (140), Lobster (100), Shrimp (100), Prawns (21).

Does your diet put you at risk? Consuming less (or no) animal foods seems to be a risk factor:

• Iodine deficiency in vegetarians and vegans.
  "One fourth of the vegetarians and 80% of the vegans suffer from iodine deficiency (iodine excretion value below 100 microg/l) compared to 9% in the persons on a mixed nutrition. The results show that under conditions of alternative nutrition, there is a higher prevalence of iodine deficiency, which might be a consequence of exclusive or prevailing consumption of food of plant origin, no intake of fish and other sea products, as well as reduced iodine intake in the form of sea salt."
• Iodine intake and iodine deficiency in vegans as assessed by the duplicate-portion technique and urinary iodine excretion
  "The probability of IDD in the group investigated was moderate to severe: three of five subgroups were classified as moderate and two subgroups were classified as severe IDD possibility. The findings highlight that vegans are an 'at risk' group for I deficiency. The I status of vegans and the subclinical effects of low I intakes and infrequent high I intakes on thyroid function in this group should be further studied. Our work has also raised the question of adequate I intakes in groups where cow's milk is not consumed, and has exposed a need for more research in this area."
• Increased risk of iodine deficiency with vegetarian nutrition
  "Our results provide experimental confirmation of literature findings indicating that I supply is higher with non-vegetarian than with vegetarian diets. Specifically, the extremely low intake and urinary output of I as analytically determined for one exemplary vegetarian diet, demonstrate that dietary I may be limiting when strict forms of vegetarian dietary practices (no iodized salt, no I supplements) are followed."

Bottom line: If you consume factory farmed meat, consume little meat and dairy, and / or avoid seafood... you should seriously consider taking iodine. Vegetarians and vegans seem to be highest at risk for deficiency. There is no RDI for iodine in CRON-o-meter so it is not a nutritional parameter that can easily be tracked.

Edited by Skötkonung, 13 April 2011 - 04:58 PM.

[Skötkonung]

A few other points:
Certain vegetables, such as cabbage and spinach, can block iodine absorption when eaten raw or unfermented. Proper iodine utilization requires sufficient levels of preformed vitamin A. In excess, iodine can be toxic. Consumption of high amounts of inorganic iodine (as in iodized salt or iodine-fortified bread) as well as of organic iodine (as in kelp) can cause thyroid problems similar to those of iodine deficiency.

[TheFountain]

A few other points:
Certain vegetables, such as cabbage and spinach, can block iodine absorption when eaten raw or unfermented. Proper iodine utilization requires sufficient levels of preformed vitamin A. In excess, iodine can be toxic. Consumption of high amounts of inorganic iodine (as in iodized salt or iodine-fortified bread) as well as of organic iodine (as in kelp) can cause thyroid problems similar to those of iodine deficiency.

Some of this might be true of people who already get enough dietary iodine and then supplement with something like kelp in excessive doses. But for vegans who supplement a little kelp iodine, we should be quite fine. I don't know where this silly connection between animal foods and iodine deficiency stems from but it sounds like fear mongering to me. These vegetarians either had poor diets or did not supplement. I bet if a raw vegans numbers were tested they would be just dandy. And remember skot, you said 'in excess, high amounts of inorganic iodine'. Most supplements are at the RDA threshold. Iodine has been generally considered thyroid protective, I think you are using the small study as a jump off point to speculate and then adding the arbitrary notion of animal foods being a better source of iodine than plant foods to these already skewed notion. Especially when the first study, involving the 700 teenage students, makes no such distinctions between vegetarian and meat based diets. Seems more like nutrient void, overly processed foods would be the culprit there.

[Skötkonung]

Some of this might be true of people who already get enough dietary iodine and then supplement with something like kelp in excessive doses. But for vegans who supplement a little kelp iodine, we should be quite fine. I don't know where this silly connection between animal foods and iodine deficiency stems from but it sounds like fear mongering to me. These vegetarians either had poor diets or did not supplement. I bet if a raw vegans numbers were tested they would be just dandy. And remember skot, you said 'in excess, high amounts of inorganic iodine'. Most supplements are at the RDA threshold. Iodine has been generally considered thyroid protective, I think you are using the small study as a jump off point to speculate and then adding the arbitrary notion of animal foods being a better source of iodine than plant foods to these already skewed notion. Especially when the first study, involving the 700 teenage students, makes no such distinctions between vegetarian and meat based diets. Seems more like nutrient void, overly processed foods would be the culprit there.

A couple points worth considering:

• Both plant and animal foods have recently decreased in iodine content due to soil depletion and changes in animal husbandry.
• Animal foods are the predominant sources of iodine. Even in best cases, terrestrial plant foods have very little iodine.
• Most vegetarians and (especially) vegans are deficient in iodine because plant foods have initially little iodine and are grown in iodine depleted soil.

These results are confirmed in multiple studies in multiple countries. Vegans and vegetarians are at a high risk for iodine deficiency. Raw vegans are probably at the highest risk for iodine deficiencies since many fruits, legumes, and vegetables are goitrogenic -- meaning they interfere with iodine uptake. Wikipedia has an excellent list of goitrogenic foods. Note that soy isoflavones are very potent goitrogens. These goitrogens will significantly reduce the bioavailability of dietary iodine. Cooking and fermentation inactivates goitrogens.

Inactivation of thyroid peroxidase by soy isoflavones, in vitro and in vivo.

I'm not surprised many omnivores are also iodine deficient because they are probably eating few sea vegetables / foods and changes in animal husbrandry has significantly reduced iodine content in meat / eggs.

Edited by Skötkonung, 14 April 2011 - 06:44 PM.

[Skötkonung]

From a vegan / vegetarian advocacy group:

"Iodine is typically undesirably low (about 50 micrograms/day compared to a recommended level of about 150 micrograms per day) in UK vegan diets unless supplements, iodine rich seaweeds or foods containing such seaweeds (e.g. Vecon) are consumed. The low iodine levels in many plant foods reflect the low iodine levels in the UK soil, due in part to the recent ice age. About half the iodine consumption of omnivores in the UK comes from dairy products."

...

"Low zinc intakes exacerbate the effect of low iodine intake. Some otherwise healthful foods contain goitrogens - substances which can interfere with iodine uptake or hormone release from the thyroid gland. These foods are generally only a concern if iodine intake is low."

...

"Most vegans have low iodine intakes but a significant minority consume excessive amounts of iodine from seaweed, particularly kelp. Both low and excessively high iodine intakes in vegans have been linked to elevated TSH levels. The optimal range for TSH appears to be 1-2 mIU/l with values below 0.5 suggesting hyperthyroidism and values above 5 suggesting hypothyroidism."

...

"The key to good thyroid function is adequate, but not excessive iodine intake. Intakes in the range 100-300 micrograms per day are desirable, though intakes up to 500 micrograms per day are probably not harmful. If taking supplements for iodine go for about 100-150 micrograms per day, to give a total intake of 150-200 micrograms per day."

...

"Consumption of more than 100g/year (by dried weight) of most seaweeds carries a significant risk of thyroid disorder due to iodine intakes in excess of 1000 micrograms per day."

I would caution against excess supplementation of iodine.

Edited by Skötkonung, 14 April 2011 - 06:53 PM.

[Michael]

I agree entirely with Sköt that vegetarians and esp. vegans are at risk of iodine deficiency. And unfortunately, it's hard to track one's intake due to wide variability and the lack of iodine info for most foods in teh USDA database. I'd also caution against using "sea vegetables" as a source, because levels in same can be EXTREMELY high and in particular kombu kelp can savage your thyroid gland (and see followup on kombu and thyroid risk).

I also agree that excess supplementation of iodine from any source is a risk, and unfortunately most supplements are kelp-derived and high-dose -- and occasionally unreliable or contaminated with arsenic.


Happily, I've discovered a good iodine supplement. I've been taking a very modest dose by splitting the tablets in four, and taking it on alternate days.

Q for Sköt: what is your basis for thinking that factory farmed meat is any more likely to be low in iodine than grass-fed? Indeed, much of the reason that milk is has become source in iodine in recent times is exactly because it's added artificially to the feed.(1)

Reference
3: Hemken RW. Milk and meat iodine content: relation to human health. J Am Vet
Med Assoc. 1980 May 15;176(10 Spec No):1119-21. PubMed PMID: 7216884.

[Skötkonung]

It was my supposition that cows fed corn and soybean meal would be more likely to be iodine depleted. Corn and soy are goitrogenic. I wasn't sure that cattle being rapidly brought to slaughter would be adequately supplemented with iodine. Dairy makes sense since the cattle will live longer and milk production falls when iodine is inadequate.

This is interesting:
Journal of Dairy Science Volume 55, Issue 7 , Pages 931-934, July 1972 Iodine Intake Related to Milk Iodine and Performance of Dairy Cattle

"Sixteen cows were fed corn silage and a concentrate mixture of corn, barley, soybean meal, and minerals starting 6 to 8 weeks prior to calving. The cows were divided into two groups and received either 6.8 or 68.0mg of supplemental iodine daily starting at 7 to 11 weeks following calving. There were no significant differences in feed intake, milk production, milk fat content, or body weight changes during the experimental period. Milk samples from 4 cows on each iodine level and from 4 cows receiving no supplemental iodine had significant differences in milk iodine. No iodine supplementation resulted in 8 μg I/liter which is evidence of a deficiency compared With 81 and 694μg I/liter for the 6.8 and 68.0mg of I feeding. Eighteen calves were fed a ration with about 40% of the dry matter as soybean meal. Three amounts of supplemental iodine (none, 1.1, and 6.8mg daily) did not produce any differences in growth rate. Feed and milk samples were obtained for iodine analysis from farms in Northern Illinois and Maryland. Differences due to location were large for forage samples. Corn silage samples were consistently lower in iodine content than hay samples collected from the same farm. No evidence of iodine deficiency based on iodine of milk was noted."

And (relating to my comment about less milk production when iodine deficient):
Journal of Dairy Science Volume 54, Issue 1 , Pages 85-88, January 1971 Goitrogenic Effects of a Corn Silage-Soybean Meal Supplemented Ration
"A group of seven cows not receiving supplemental iodine bore calves with enlarged thyroid glands, consumed less feed, produced less milk with a lower milk fat content, and lost less weight during early lactation than another seven cows receiving supplemental iodine. All cows were fed corn silage as the only forage and a concentrate mix of corn, barley, soybean meal and minerals. In a second trial 16 cows were fed corn silage as the only forage. Half received soybean meal as a source of protein and the others received cottonseed meal and urea. Cows receiving the soybean meal produced calves with larger thyroid glands; however, milk production was not evaluated due to the removal of cows from the experiment. The goitrogenic effect of a corn silage-soybean meal ration appears due to soybean meal."

[Skötkonung]

Happily, I've discovered a good iodine supplement. I've been taking a very modest dose by splitting the tablets in four, and taking it on alternate days.

What do you think about getting iodine from fortified salt?

[HaloTeK]

Micheal, you say that you split your supplement into 4. Which means your typical dose is 225/4 = 56.25mcg on the days that you supplement (which is to say not every day). Obviously you feel you get enough iodine from food for the most part.

Do you have an upper limit per day for iodine considering the RDA is 150mcg a day.

I am still partial to this supplement (it doesn't seem to aggravate as potassium-iodide).
http://www.wellnessr...osol_iodine.php

It is a water soluble iodine.


Usually I dilute it to 1/4 dose and take it once a week. Which gives me a dose of about 450mcg. Do you think I have to break this up or is this ok to do at once.

[Michael]

It was my supposition that cows fed corn and soybean meal would be more likely to be iodine depleted. Corn and soy are goitrogenic.

Right, but that's because they block uptake of iodine by the thyroid, not because they block uptake from the gut. The meat could well have the normal level of iodine, even if goiterogenic feed made them functionally iodine-deficient. And, IAC, pasture forage also often contains goiterogens, such as Leucaena; similarly, "cyanogenetic goitrogens include the thiocyanate derived from cyanide in white clover and the glucosinolates found in some Brassica forages such as kale, turnips, and rape."

Happily, I've discovered a good iodine supplement. I've been taking a very modest dose by splitting the tablets in four, and taking it on alternate days.

What do you think about getting iodine from fortified salt?

Since most people already ought to cut their sodium intake in half, I don't think intentionally consuming more table salt is a good solution for almost anyone.

[Skötkonung]

It was my supposition that cows fed corn and soybean meal would be more likely to be iodine depleted. Corn and soy are goitrogenic.

Right, but that's because they block uptake of iodine by the thyroid, not because they block uptake from the gut. The meat could well have the normal level of iodine, even if goiterogenic feed made them functionally iodine-deficient. And, IAC, pasture forage also often contains goiterogens, such as Leucaena; similarly, "cyanogenetic goitrogens include the thiocyanate derived from cyanide in white clover and the glucosinolates found in some Brassica forages such as kale, turnips, and rape."

Good point but corn and soy have very little iodine content as-is, likely due to poor growing conditions. Basically cows are being fed an iodine deficient diet full of goitrogens. I'm not expecting them to have adequate levels of iodine in their flesh. Pasture may also contain some goitrogens, but the food source as a whole provides a better source of iodine. Plus, cows tend to due better in terms of total health outcomes on silage / pasture than on corn and soy feed (these types of food cause intestinal ulceration, liver disorders, and likely contribute to O157:H7 contamination). Because of this, it seems like a reasonable supposition that cattle may have digestive mechanisms better suited towards handling goitrogens found in pasture.

When I was looking for the iodine values in beef, I found they varied quite a bit based on the source of the meat and feeding conditions.

Changes in Plasma Iodine Levels in Beef Cattle Turned Out to Spring Pasture
This study (apologies if you don't understand German) found that the serum iodine levels increased 24% on pasture versus hay silage.

Edited by Skötkonung, 14 April 2011 - 10:51 PM.

[TheFountain]

I respectfully disagree with both skot and michael on this subject.

If you two are contending that iodine deficiency is evident in normal vegetarian diets, without any emphasis on nutrient source or variation, I would tend to agree, especially in those who do it specifically for 'ethical' reasons. These people are not vegetarians or vegans for health reasons. Therefor their diets are not very well constructed to that end. That and the fact that alot of people, both vegetarian and non-vegetarian have iodine deficiencies, should be cause to reconsider said position. I personally consume alot of seaweed and I supplement with iodine. Therefor I do not foresee a problem.

Wait, lacto-ovo vegetarians should have fine iodine numbers because they tend to eat alot of dairy. *smacks self*.

[Skötkonung]

Wait, lacto-ovo vegetarians should have fine iodine numbers because they tend to eat alot of dairy. *smacks self*.

One study listed in my initial post indicates that 25% of vegetarians versus 80% of vegans have iodine deficiency. Mixed nutrition reduced iodine deficiency to 9% for omnivores. Since the vegetarian category includes eggs and cheese (otherwise they would have been considered vegans) it seems reasonable to assume that dairy and eggs alone are either 1.) not being consumed in adequate amounts by the vegetarian group or 2.) they don't provide enough iodine to completely protect against deficiency. It's probably a combination of both.

The thing that scares me about getting most of my iodine from dairy is the high casein (protein) levels. And I'd still be cautious about too much seaweed.. I like Michael's approach to supplementation, though!

[Sillewater]

I agree entirely with Sköt that vegetarians and esp. vegans are at risk of iodine deficiency. And unfortunately, it's hard to track one's intake due to wide variability and the lack of iodine info for most foods in teh USDA database. I'd also caution against using "sea vegetables" as a source, because levels in same can be EXTREMELY high and in particular kombu kelp can savage your thyroid gland (and see followup on kombu and thyroid risk).
....

Wow did not know that seaweed varied that much. I have been getting my iodine intake from seaweed (eaten twice a week). But daily I get it from half and half salt.

Thanks for the interesting post Skot.

[niner]

Happily, I've discovered a good iodine supplement. I've been taking a very modest dose by splitting the tablets in four, and taking it on alternate days.

That's exactly what I use, only I'm taking an entire pill every day; eight times your dose. That concerns me, since your diet is very carefully considered. Other than supplementation, my diet is not very high in iodine. I suspect that I was borderline if not frankly deficient for many years, and I noticed a distinct improvement in my usual mid-winter mood decline after I began use of iodine. What would one look for if guarding against iodine excess?

[maxwatt]

... What would one look for if guarding against iodine excess?

Elevated TSH. Goiter in extreme cases. Unlikely if daily intake < 2000mcg.

[APBT]

... What would one look for if guarding against iodine excess?

Elevated TSH. Goiter in extreme cases. Unlikely if daily intake < 2000mcg.

I believe - someone please correct me if I'm wrong - elevated TSH is hypothyroid (underactive). Meaning low circulating hormone levels. Low TSH is hyperthyroid (overactive). An excess of iodine could lead to low TSH (hyperthyroid).

[maxwatt]

... What would one look for if guarding against iodine excess?

Elevated TSH. Goiter in extreme cases. Unlikely if daily intake < 2000mcg.

I believe - someone please correct me if I'm wrong - elevated TSH is hypothyroid (underactive). Meaning low circulating hormone levels. Low TSH is hyperthyroid (overactive). An excess of iodine could lead to low TSH (hyperthyroid).

TSH increases with excess iodine, whilst T4 and T3 decrease. Excess iodine can cause goiter, as can too little. See abstract below.

Journal of Clinical Endocrinology & Metabolism Vol. 87, No. 12 5499-5502
Copyright © 2002 by The Endocrine Society

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

Elizabeth N. Pearce, A. Russell Gerber, David B. Gootnick, Laura Kettel Khan, Ruowei Li, Sam Pino and Lewis E. Braverman
Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine (E.N.P., S.P., L.E.B.), Boston, Massachusetts 02118; Peace Corps Office of Medical Services (A.R.G.), Washington, D.C. 20526; U.S. General Accounting Office (D.B.G.), Washington, D.C. 20008; National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition and Physical Activity, Centers for Disease Control and Prevention (L.K.K., R.L.), Atlanta, Georgia 30341

Abstract

A cross-sectional survey of 102 Peace Corps volunteers in Niger, West Africa, in 1998 had previously demonstrated a high rate of thyroid dysfunction and goiter attributable to excess iodine from their water filters. The Peace Corps volunteers were followed-up a mean of 30 wk after they ceased using iodine-based water filtration systems. Goiter was present in 44% of subjects during excess iodine ingestion and in 30% after removal of excess iodine. Mean serum iodine decreased from 293 µg/liter during excess iodine ingestion to 84 µg/liter after cessation of excess iodine. Mean total serum T4 values increased from 100.4 to 113.3 nmol/liter (7.8 to 8.8 µg/dl). Mean serum free T4 increased from 32.2 to 34.7 pmol/liter (2.5 to 2.7 ng/dl). Mean serum TSH decreased from 4.9 to 1.8 mU/liter. Mean serum thyroid peroxidase antibody levels decreased from 33,000 to 22,000 IU/liter (33 to 22 IU/ml).

[yoyo]

I get a lot of iodine through kombu. But i also use iodized sea salt.

I use the iodized salt in fermented products (mostly my sourdough oatbran/buckwheat flatbread), as well as some foods that don't do with soy sauce etc. I do not notice any problem with the iodine and fermentation, which some people say is a reason not to use iodized salt. Also salt loses its iodine quickly in humid/warm environments.

[APBT]

... What would one look for if guarding against iodine excess?

Elevated TSH. Goiter in extreme cases. Unlikely if daily intake < 2000mcg.

I believe - someone please correct me if I'm wrong - elevated TSH is hypothyroid (underactive). Meaning low circulating hormone levels. Low TSH is hyperthyroid (overactive). An excess of iodine could lead to low TSH (hyperthyroid).

TSH increases with excess iodine, whilst T4 and T3 decrease. Excess iodine can cause goiter, as can too little. See abstract below.

Journal of Clinical Endocrinology & Metabolism Vol. 87, No. 12 5499-5502
Effects of Chronic Iodine Excess in a Cohort of Long-Term American Workers in West Africa
Elizabeth N. Pearce, A. Russell Gerber, David B. Gootnick, Laura Kettel Khan, Ruowei Li, Sam Pino and Lewis E. Braverman

A cross-sectional survey of 102 Peace Corps volunteers in Niger, West Africa, in 1998 had previously demonstrated a high rate of thyroid dysfunction and goiter attributable to excess iodine from their water filters. ...

Max

Thanks for the edification and clarification. I could have sworn I'd read - somewhere - that iodine could/would lower TSH. If I find anything that supports that, I'll post it.

Edited by Michael, 27 June 2011 - 06:12 PM.
trim quotes

[Michael]

Happily, I've discovered a good iodine supplement. I've been taking a very modest dose by splitting the tablets in four, and taking it on alternate days.

That's exactly what I use, only I'm taking an entire pill every day; eight times your dose. That concerns me, since your diet is very carefully considered.

To be honest, I'm really not clear what made me adopt such a conservative dose. I've just upped it to 1/4 pill per day, or ~1/3 RDA, which still leaves me a lot of space for dietary iodine without bumping up against likely toxicity. (To answer HaloTeK's Q: the UL is 1100 µg; a hyper-conservative 500 µg is unlikely to be hit by someone who doesn't eat a lot of seafood, kelp products, or have water contamination. But there have been plenty of unexpected negative side-effects from safe-looking supplements so far, so 1/3 of dietary requirements already strikes me as a generous dose.

What would one look for if guarding against iodine excess?

That's tricky, because depending on what exactly it does you could wind up hypo- or hyperthyroid. A slight elevation of TSH can be a clue, as maxwatt indicates, but can also be due to a lot of other things (including CR). Advanced toxicity can cause goiter -- as, unfortunately, can deficiency. The best test for thyroid problems linked to thyroid toxicity is anti-TPO antibodies, AFAIK.

It was my supposition that cows fed corn and soybean meal would be more likely to be iodine depleted. Corn and soy are goitrogenic.

Right, but that's because they block uptake of iodine by the thyroid, not because they block uptake from the gut. The meat could well have the normal level of iodine, even if goiterogenic feed made them functionally iodine-deficient.

Good point but corn and soy have very little iodine content as-is, likely due to poor growing conditions.

That really has a lot more to do with the geology of the soil in a given area than the specific plant used for feed. Having a hard time finding a specific map on this, but see eg:



This is actually for soil, but is rather hard to see:

Basically cows are being fed an iodine deficient diet full of goitrogens.

Well, again: they may or may not be fed a deficient diet, depending on the soil -- and goiterogens don't affect the quantity of iodine in the meat.

When I was looking for the iodine values in beef, I found they varied quite a bit based on the source of the meat and feeding conditions.

I respectfully disagree with both skot and michael on this subject.

If you two are contending that iodine deficiency is evident in normal vegetarian diets, without any emphasis on nutrient source or variation, I would tend to agree, especially in those who do it specifically for 'ethical' reasons. These people are not vegetarians or vegans for health reasons. Therefor their diets are not very well constructed to that end. ...

Wait, lacto-ovo vegetarians should have fine iodine numbers because they tend to eat alot of dairy. *smacks self*.

... or not. The problem is that, even if you're conscious of the issue,it's difficult to construct a vegetarian diet that is confidently iodine-adequate, because you just don't know what's in the food. Omnivores are much less likely to do so, and median intakes in the USA give plenty of room.

I get a lot of iodine through kombu. But i also use iodized sea salt.

Again: seaweeds, and especially kombu, are not safe sources of iodine. See links in my earlier post. Do not use them.

[yoyo]

You link indicated kelp supplements could have arsenic in them. I went and read the paper, and a follow up, and i do not get the impression that moderate amount of seafood such as seaweed are a significant or unique risk for arsenic toxicity.

[TheFountain]

You link indicated kelp supplements could have arsenic in them. I went and read the paper, and a follow up, and i do not get the impression that moderate amount of seafood such as seaweed are a significant or unique risk for arsenic toxicity.

You will find that anti-vegetarian/vegan propaganda is very high on these forums. Now we must fear supplements because of all sorts of icky toxicities! lol

I bet there are more free toxic substances in factory farmed meats than in any would be 'vegan' designed supplement out there.

[yoyo]

You link indicated kelp supplements could have arsenic in them. I went and read the paper, and a follow up, and i do not get the impression that moderate amount of seafood such as seaweed are a significant or unique risk for arsenic toxicity.

You will find that anti-vegetarian/vegan propaganda is very high on these forums. Now we must fear supplements because of all sorts of icky toxicities! lol

I bet there are more free toxic substances in factory farmed meats than in any would be 'vegan' designed supplement out there.

definately the case for arsenic, since its in chicken feed.

[niner]

You link indicated kelp supplements could have arsenic in them. I went and read the paper, and a follow up, and i do not get the impression that moderate amount of seafood such as seaweed are a significant or unique risk for arsenic toxicity.

You will find that anti-vegetarian/vegan propaganda is very high on these forums. Now we must fear supplements because of all sorts of icky toxicities! lol

I bet there are more free toxic substances in factory farmed meats than in any would be 'vegan' designed supplement out there.

definately the case for arsenic, since its in chicken feed.

Are you saying that chicken is a significant source of arsenic? That it's even close to dangerous? Frankly, that would surprise me.

On the other hand, supplements are capable of containing practically any toxic substance. Many supplement producers do not analyze their source chemicals, or they don't analyze every lot. It's certainly possible to make a supplement that's clean, but it's also easy not to.

[Sillewater]

For those of us who eat a ton of raw cruciferous vegetables (like me) iodine is something we should probably be concious of:

• Cancer Causes Control. 2010 Aug;21(8):1183-92. Epub 2010 Apr 2.Role of dietary iodine and cruciferous vegetables in thyroid cancer: a countrywide case-control study in New Caledonia.Truong T, Baron-Dubourdieu D, Rougier Y, Guénel P. PMID: 20361352

However MR's warning about kombu (and probably other related seafood products) shouldn't be dismissed lightly:

• Hormones (Athens). 2007 Jan-Mar;6(1):25-35.The role of iodine in the evolution of thyroid disease in Greece: from endemic goiter to thyroid autoimmunity.Fountoulakis S, Philippou G, Tsatsoulis A. PMID: 17324915

Man, I live in Vancouver and its hard to get away from the sushi.

[motif]

I take easy to do by yourself supplement - few drops of lugol solution in water.
e.g. 1 drop of 5% of lugol solution contains 6mgs of iodine. Take this since years, usually
12 drops a day with longer or shorter breaks.

[TheFountain]

Happily, I've discovered a good iodine supplement. I've been taking a very modest dose by splitting the tablets in four, and taking it on alternate days.

Why did you choose this form of iodine and this specific company 'now foods'? Research or just happenstance?

Edited by TheFountain, 26 June 2011 - 02:25 PM.

[Michael]

Happily, I've discovered a good iodine supplement.

Why did you choose this form of iodine and this specific company 'now foods'? Research or just happenstance?

Because it's hellishly hard to find ANY standalone iodine supplement, with the pseudo-exception of kelp-based supplements which as I indicated are unreliable and often contaminated.

NOW appears to me to be a generally reliable source for commodity-item supplements.

[TheFountain]

Happily, I've discovered a good iodine supplement.

Why did you choose this form of iodine and this specific company 'now foods'? Research or just happenstance?

Because it's hellishly hard to find ANY standalone iodine supplement, with the pseudo-exception of kelp-based supplements which as I indicated are unreliable and often contaminated.

NOW appears to me to be a generally reliable source for commodity-item supplements.

I ask because I am considering trying out this liquid version of potassium iodide. It's cheap and I can more easily control the dose than having to cut pills up into four pieces or what have you.

http://www.iherb.com...l/7775?at=0&x=1

Edited by TheFountain, 27 June 2011 - 06:49 PM.