Iodine Supplements Before, During, and After Pregnancy


“Iodine Supplements Before,
During, and After Pregnancy” Although severe iodine deficiency
was eliminated in the United States nearly a century ago after the
introduction of iodized salt, iodine intake has declined
in recent decades. Public health efforts
to limit salt intake to decrease cardiovascular risk, in conjunction with increasing
use of non-iodized salt may in part be to blame. Now not adding salt to
food is a good thing, as sodium is considered the second
leading dietary killer in the world, second only to not
eating enough fruit, but if you do
add table salt, make sure it’s iodized,
as it is a myth, and often also
false advertising, that so called “natural” sea salt contains
significant amounts of iodine. Fruits and vegetables
provide iodine, but the amounts can vary
depending on where it’s grown; how much iodine’s in the soil. Because iodine is
particularly important for fetal brain development, there’s a recommendation
that all US women who are pregnant, lactating, or
even planning a pregnancy should ingest dietary supplements containing 150mcg of
potassium iodide per day. Is there evidence that
they’re not getting enough now? Well, we’d like to see urine
levels in pregnant women over 150, but in the U.S. pregnant women
only average about 125. For example, a recent
survey in New York City showed only about half
of pregnant women were making the cut. Don’t most women take
prenatal vitamins though? Only about half of
prenatal multivitamins contain any iodine at all and so only about 1 in 5
pregnant women in the U.S. are following the recommendations
of the American Thyroid Association to take a daily
iodine supplement, specifically in the form
of potassium iodide rather than seaweed, as the levels in seaweed are
subject to natural variability. Though the iodine content
was as much as 90% off in some of the potassium
iodide prenatal supplements, the kelp supplements
varied even wider, off by as much as 170%. Now the American Thyroid Association
admits they don’t have evidence that the current borderline
insufficiency levels are leading to
undesirable outcomes, and so their rationale
that all pregnant women take iodine supplements
is a bit tenuous, but until such data
is available they figure better
safe than sorry. A randomized placebo-controlled
interventional trial would answer the question
once and for all, but the existing evidence for iodine
supplementation during pregnancy is so convincing that it would
be considered unethical to randomize pregnant
women to a placebo. And so when it comes to sufficient
iodine intake during pregnancy I’d recommend
just do it.