(Nature's Way) In order for the thyroid gland to function properly, it must have a ready supply of natural food based iodine. Nature's Way Kelp contains 400 mcg. of iodine, which is 267% of your daily intake. Since this iodine is food based, it will not accumulate in the body causing a toxic condition, as would iodine prepared from a chemically based drug. One capsule daily with food.