Rainforest foods spirulina powder 200g a microscopic plant that grows in fresh water spirulina contains more essential nutrients than almost any food available it is an excellent source of protein which is easily absorbed by the body and contains high concentrations of all eight essential amino acids spirulina contains significantly more vitamin a than carrots up to 50 times more iron than spinach and over 25 times the calcium of milk it is a powerful source of antioxidants including