Dr. Stephanie Bloom et al. (10.1542/peds.2015-4003) at University of Michigan call our attention in an interesting set of case reports to what appears to be a growing problem of nutritional deficiencies in the diet of young patients who have restricted their food intake. The restrictions are self or parentally imposed and spring from the belief that the child and/or family is pursuing a healthier diet.
In one of the reported cases, a casein free/ gluten free restricted diet had led to the patient developing hypothyroidism and goiter which corrected with the use of L-thyroxin and iodine supplementation. Eventually thyroid function remained corrected on iodine alone. The second patient who also developed hypothyroidism had food aversions and atopy which added dairy elimination to his already very restricted diet including use of only sea salt as the source of this seasoning.
Dr. Bloom points out that iodization of salt was a highly successful public health measure when it was begun in the US in the 1920s and iodine deficiency was effectively eliminated thereafter. Gluten free diets which eliminate commercially prepared bread also eliminate the iodate use as a bread conditioner. Casein free diets eliminate the iodine in dairy products which is present as an iodine-based cleaner used in product processing. Also the growing interest in using sea salt effectively sidesteps the iodinated salt that has been the grocery store standard for the last century.
Iodine is likely only one of the micronutrient deficiencies that will be seen as families unfortunately adopt fad elimination diets promulgated on the internet without the advantage of the enormous progress made in the nutritional sciences over the last hundred years.
