1
$\begingroup$

I’ve come across a few other people asking this question on different forums such as on Quora, and Reddit…

With my current understanding, we evolved from sea creatures which is why we still need iodine in our system.

The RDA is 150 mcg, 220 for pregnant women.

Isn’t this amount of iodine something a person can get merely from sea plants and sea animals?

Do land animals need such a high amount of iodine as well, and are a majority of them iodine deficient? Unless there is some way for them to get iodine from land plants. Or are we supposed to eat iodine rich soil?

If sea plants and sea animals are a required for proper iodine RDA, this implies that they should be staple foods within our diets.

Sorry for all the questions.

$\endgroup$
4
  • $\begingroup$ Thyroid Hormone is needed by nearly every cell in our bodies, and without it, we would die. And, as @David said, Iodine is an integral part of the hormone. As a requirement for vertebrates, it is also found in vertebrates (whose products and flesh we consume) as well as in their diets. The majority of vertebrates today are not iodine deficient, but in the past, humans were moreso than they are today. $\endgroup$ Feb 6 at 17:41
  • 2
    $\begingroup$ saying sorry does get around the one question per post policy, I suggest looking up the goiter line to get a lot of answers at once. Iodine is only limited in specific environments. $\endgroup$
    – John
    Feb 10 at 3:46
  • $\begingroup$ @John I lean towards a mostly vegan diet. So it interests me that unless a vegan eats seaweed, supposedly they aren’t getting enough iodine. But I can only assume that realistically if an environment has soil that is rich in iodine then sea plants wouldn’t be a requirement. $\endgroup$
    – Lecifer
    Feb 17 at 15:57
  • $\begingroup$ that's a problem with a vegan diet, IE without and meat, dairy or eggs. non-sea plants in general are low in iodine. most animals including most herbivores get them from the same places we do eating animals or eggs.. Or they are bulk plant feeders and make up for it with sheer volume and eating plants that would be toxic to us. keep in mind a 100lb deer will eat almost 10lb of vegetation a day plus the occasional bird or egg. $\endgroup$
    – John
    Feb 18 at 17:48

1 Answer 1

4
$\begingroup$

Iodine is a component of the thyroid hormones, thyroxine and triiodothyronine, so it is indeed a human nutritional requirement.

According to this Harvard University webpage, milk (especially), eggs and other dairy products are sources of iodine, as well as fish, mentioned by the original poster. In addition, in advanced countries iodine is added to table salt to help combat iodine deficiency.

Although iodine is also added to the diet of dairy cows, I have read that iodine is also present in their natural food. Iodine enters the soil from marine spray in coastal areas, and from rainfall further inland, and is retained by metals in the soil. It can therefore be taken up by plants. However I do not know which plants that would constitute a natural bovine diet are particularly rich in iodine or why that would be so.

$\endgroup$
3
  • 1
    $\begingroup$ I am not so sure that the cows that are being eaten regularly see any of their "natural food" ever, as they are not maintained on grass. $\endgroup$
    – CaroZ
    Feb 8 at 13:36
  • $\begingroup$ @CaroZ — It's their milk. You have to approach these things from a historical viewpoint — when dairy farming emerged originally the cattle would certainly have been maintained on grass. As for the contemporary situation in factory farms, iodine is actually added to animal feed, so supermarket milk in Britain and the US is, in fact, a good source of iodine. $\endgroup$
    – David
    Feb 8 at 16:15
  • $\begingroup$ Thanks for the answer! I lean towards a mostly vegan diet. So it interests me that unless a vegan eats seaweed, supposedly they aren’t getting enough iodine. But I can only assume that realistically if an environment has soil that is rich in iodine then sea plants wouldn’t be a requirement. $\endgroup$
    – Lecifer
    Feb 17 at 15:57

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .