Wakame seaweed is a good source of vitamin A. Kelp and other types of seaweed contain measurable amounts of vitamins C, E and K, as well as niacin, folate and choline.ulse is also a source of potassium, and all seaweeds provide magnesium, iron and zinc among other minerals. Kelp is a good source of calcium, offering 17 percent of daily needs in one cup.