Endemic thyroid iodine content

We have already cited evidence to indicate that iodine needs vary substantially from individual to individual. Not only does the thyroid hormone content of the blood show high inter-individual variation, but in endemic regions not all individuals exhibit simple goiter due to iodine deficiency. And, in nonendemic regions where the iodine content of the foods is sufficient for most individuals, there are still some who suffer deficiency. Furthermore, even the iodine in iodized salt is said to be sufficient to yield unfavorable results for some individuals. 

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