Kelps are seaweeds that grow in particular shallow and nutrient-rich waters around the world. They've been eaten and used medicinally for hundreds of years in various forms. Sea kelp is a natural source of vitamins A, B1, B2, C, D and E, as well as minerals including zinc, iodine, magnesium, iron, potassium, copper and calcium. It contains the highest natural concentration of calcium of any food and 10 times more than milk. The nutrients in kelp are said have many health benefits, including potentially helping with weight loss, anti-ageing and hair growth.