Spirulina is a micro alga grown in protected ponds for commerial harvesting and human consumption. It is 60% protein with known immune enhancing ability, partly due to its content of calcium spirulan, a component of spirulina known to boost immunity. Others key nutrients include the rich, blue pigment, phycocyanin. This polypeptide (protein) stimulates stem cells in bone marrow to produce both red and white blood cells. It is so effective that stem cells damaged by radiation or toxic chemicals can even be made to respond and build healthier blood.