Now Kelp Supplement is a nutritional powerhouse supplement that contains iodine from the greatest natural sources. Kelp is a big, leafy seaweed from the brown algae family that grows in "forests" in the world's cooler oceans. Kelp has been used for generations as a healthful staple ingredient in Chinese, Japanese, and Korean cuisine. Kelp contains a high concentration of naturally occurring and accessible iodine. It is also high in iodine, which has been demonstrated to be necessary for proper thyroid function. Your thyroid needs iodine to function correctly. Iodine is not produced by the body, hence it must be obtained through diet. Iodine deficiency can cause goiter (enlargement of the thyroid gland) and have an impact on your metabolism. NOW kelp dietary supplement provides the natural nutritional profile found in genuine whole foods.