Hey ,
This supplement contains kelp (brown seaweed) extract which is high in iodine. Recommended for adults is that we consume 140 mcg daily.
Since I don’t know this supplement, I will provide you details on iodine amounts and thyroid health.
How much iodine is in brown seaweed/kelp
Although some sources mention that kelp can contain around 1000 mcg of iodine in 1 gram of kelp, the amount can vary greatly per batch, making it hard to determine the amount of iodine in kelp supplements.
What happens with high dosages of Iodine?
Low iodine intake can cause hypothyroidism, but less known is that a high intake of iodine can also aggravate thyroid issues. In fact, some people can experience hypothyroidism with daily dosages of iodine above 2 mg because they can’t adapt to the amount of iodine and it in time starts to inhibit thyroid hormone production. Some people can experience hyperthyroidism with these amounts of iodine and other people have no problem at all.
Kelp & Thyroid medications
I know that patients taking levothyroxine (medication used with hypothyroidism) are advised to avoid using kelp products since it can alter the amount of medication they should use in an unpredictable way (you can find more information about that here). It is probably for this reason, the warning is on the product.
Advise
Since the amount of iodine isn’t specified here and I don’t exactly know what the concentration of iodine in the kelp extract is, I can’t answer the question with certainty, but I suspect the warning is there for people who are on levothyroxine or other thyroid medication.
Perhaps if you send them an email, they can clarify what they mean with their warning