Dasgupta (July 1/10)
Iodine is an essential element. I hardly need tell this group that iodine is needed to make thyroid hormones. If you are getting enough iodine you do not have any need for iodine supplements. If you are not pregnant or lactating and your vitamins have a stated content of 150 mcg iodine (an amazingly high fraction say they have 150 mcg I but actually have 150 mcg of KI which is about 115 mcg I), you are doing ok. Sadly you cannot go to your doctor and get a urinary iodine analysis done; it is not a routine procedure. So there is no easy way for you to know if you are iodine deficient. As I said above, there are reasons to be concerned about the iodine nutrition of women of childbearing age. The suggested daily requirement for an expecting mother is 220 mcg whereas that for a lactating mother is 290 mcg and many are interested in getting these numbers higher. Many people (especially adult women) who show signs of hypothyroid conditions do so because they are not getting enough iodine, not because the thyroid is malfunctioning. Exclusively breastfed babies really need their iodine – thyroid hormones in the neonates govern brain development – this is why WHO and UNICEF go into all the developing countries with salt iodization programs. WHO has categorically stated: Iodine deprivation is the single most preventable cause of mental retardation. In the US and in Canada, even you begin to believe that you are iodine deficient, you cannot go to your corner drugstore and easily buy an iodine supplement as you can buy, e.g. Zinc, Iron, or Selenium supplements. Going to Health/Nutrition food suppliers and buying kelp capsules is not an acceptable solution, the content varies greatly and depending on how it has been harvested kelp may contain an unacceptable amount of toxic heavy metals. Many countries, for example, Germany, have adopted universal salt iodization (USI), where all food grade salt is iodized. I do not know if this is the case for Canada. However, the goal for USI is that at least 92% of households have easy access to iodized salt; this is certainly the case for US and Canada. Having access and using it are not of course the same. You have told me several times that all “Table Salt” in Canada is iodized. By far the large majority of “Table Salt”, e.g., bulk of what you can buy in grocery stores in the US is also iodized. But it is only 20% of the total salt we eat in the US. The salt that is in fast/pre-packaged/pre-prepared foods is not iodized; this goes from McDonald’s to Campbell’s Soup. They may have iodized salt on the tables at McDonald’s to sprinkle even more salt on your fries but that is not what they are using back in the kitchen, at least in the US.
How much is too much? Most agree that as long as you do not change your iodine intake abruptly, amounts up to 1100 mcg a day are perfectly safe; many believe that the real safe limit is 2 to 5 times that much (similar to the average intake in northernmost Japan). There is thus little risk of overdosing yourself on iodine.
Iodine supplements in modest dosage amounts (200 mcg) are free to all expecting and new mothers in Spain, thanks to the efforts one valiant physician/researcher. While there is no country where thyroid disorders/ thyroid cancer is nonexistent, thyroid health (or for that matter general health) is the best in Japan, which also happens to have the highest iodine intake. While better health is not due to iodine nutrition alone, it certainly contributes. In the following, my remarks concern only the US because I am not sure if Canada has really adopted Universal Salt Iodization. Iodine nutrition, especially in young children, has social consequences. Consumption of pre-packaged or fast food is much greater among the less affluent, leading to, and perhaps even perpetuating, the iodine gap. The less advantaged are getting more salt and less iodine. I personally see it as a simple question:
This site complies with the HONcode standard for trustworthy health information: