It is a very rich single source of natural vitamins and minerals, including essential trace minerals. It contains iodine, iron, sodium, phosphorus and calcium, as well as magnesium and potassium. Kelp has a reputation for being an especially good source of iodine and potassium. Kelp is a source of vitamins A, B1, B2, C, D and E, plus amino acids. Kelp also makes a popular salt substitute. Because the plant's nutrients come in a natural form, they are easily assimilated by the body. Kelp is especially high in iodine, which must be present for proper glandular function and metabolism. Iodine feeds the thyroid which controls metabolism. Iodine is important for thyroid disorders (both overactive and underactive) and obesity. Kelp is used for weight loss. Kelp contains a viscous fiber called algin. Algin absorbs most nutrients as well as toxins from the digestive tract. This reduces both caloric intake and toxins entering the circulatory system. Alginic acid binds and removes radioactive strontium 90 from the body. Known Hazards: Don't use if you are allergic to iodine in any form, particularly if you have had an allergic reaction to injected dye used for X-ray studies of the kidney or other organs. Doses of iodine in excess of 150 micrograms a day can induce or worsen an overactive thyroid gland.