Kelp

Kelp is included here as an example of the “sea vegetables”—oceanic plants that are eaten in many parts of the world, from Ireland and the Canadian Maritimes to Japan and Korea. They are especially rich in minerals, including calcium, iodine, iron, magnesium, and trace minerals. They also contain vitamin A.
Because of the mineral-rich environment of the sea, kelp provides the broadest range of minerals of any food. Kelp is an excellent source of vitamin K, and provides the B vitamins folate, riboflavin, and pantothenic acid. People who eat kelp have been found to have a lower risk of intestinal and breast cancers. Sea vegetables are an excellent source of iodine, necessary to healthy thyroid function and the prevention of goiter. If you have stopped using ordinary iodized table salt, you may wish to add sea vegetables to your meals to provide this essential mineral. You can even keep a container of kelp flakes on the dinner table and use it instead of table salt for seasoning foods.
Nutritional Facts :
Three and one-half ounces of raw kelp provides 43 calories, 9.6 g carbohydrate, 1.7 g protein, 0.6 g fat, 1.3 g dietary fiber, 116 IU vitamin A, 3 mg vitamin C, 180 mcg folic acid, 89 mg potassium, 42 mg phosphorus, 233 mg sodium, 168 mg calcium, 2.85 mg iron, 121 mg magnesium, and 1.23 mg zinc.