Iodine in seaweed is a natural source which is essential to human life. The thyroid gland adds iodine to the amino acid tyrosine to create these hormones. Without sufficient iodine, your body cannot synthesize them. Because these thyroid hormones regulate metabolism in every cell of the body and play a role in virtually all physiological functions, an iodine deficiency can have a devastating impact on your health and well-being. A common sign of thyroid deficiency is an enlarged thyroid gland, commonly called a goiter. Goiters are estimated to affect 200 million people worldwide, and in all but 4% of these cases, the cause is iodine deficiency.
Dr. Ryan Drum, noted herbalist and sea vegetable gatherer, states in Therapeutic Use of Seaweeds (Proceedings of the 2001 Pacific Northwest Herbal Symposium) "Seaweeds, eaten regularly, are the best natural food sources of biomolecular dietary iodine, no land plants are reliable sources of dietary iodine." For comparison, you would have to eat about 40 lb. of fresh vegetables and/or fruits to get as much iodine as you would from 1 gram of our whole leaf kelp. Iodine is the main component of the hormone produced by the thyroid gland, which regulates our metabolism - thyroid hormone accelerates cellular reactions, increases oxygen consumption and basal metabolism, and influences growth and development, energy metabolism, differentiation, and protein synthesis.
Dr. Linda Rector Page, author and herbalist, writes in Healthy Healing: "Iodine is essential to life, it is an important element of alertness, and rapid brain activity, and a prime deterrent to arterial plaque. Iodine is also a key factor in the control and prevention of many endocrine deficiency conditions prevalent today, such as breast and uterine fibroids, tumors, prostate inflammation, adrenal exhaustion, and toxic liver, and kidney states."
Unfortunately, not all iodine is good for us and the human thyroid cannot distinguish between life sustaining iodine-127 (like iodine in seaweed) and radioactive iodine-131. A full body load of iodine-127 from seaweeds will tend to allow the body to reject topical and air and food-source iodine 131." We all need between 150 and 1100 micrograms in our daily diets to keep our thyroids healthy and prevent uptake of radioactive Iodine. By "loading" the thyroid with healthy Iodine-127 it will not absorb the toxic iodine-131. Healthy thyroids will not absorb unneeded iodine and it is transported out the “natural way”.
It's important to understand that there are different sorts of iodine. Very often when the National Food Administration talk about the danger with iodine, they should refer to the right iodine like table salt, which is not the best source of iodine.