Spirulina is one of the natural sources containing the highest amount of protein. Spirulina provides the majority of essential and nonessential amino acids. It has a fairly well-balanced amino acid pattern and contains the highest amount of beta-carotene, a precursor of vitamin A. It is the only vegetable source of vitamin B12. It is also the source of the essential fatty acid γ-linolenic acid which is the precursor of hormones involved in regulation of body functions. The constituents of spirulina include protein (50-70%) including all essential amino-acids, essential fatty acids, polysaccharides, B vitamins particularly vitamin B12, beta-carotene and minerals particularly iron.