Bladderwrack is rich in iodine, calcium, magnesium, potassium, sodium, sulfur, silicon and iron and high in some B-complex vitamins. It contains moderate amounts of phosphorus, selenium, manganese and zinc and small amounts of vitamins A, C, E and G. It also contains anti-sterility vitamin S as well as vitamin K. It is rich in algin and mannitol, carotene and zeaxantin with traces of bromine.