Spirulina contains rich vegetable protein (60~ 63 %, 3~4 times higher than fish or beef ), multi Vitamins (Vitamin B 12 is 3~4 times higher than animal liver), which is particularly lacking in a vegetarian diet.
It contains a wide range of minerals (including Iron, Potassium, Magnesium Sodium, Phosphorus, Calcium etc.), a high volume of Beta- carotene which protects cells (5 time more than carrots, 40 time more than spinach), high volumes of gamma-Linolein acid (which can reduce cholesterol and prevent heart disease).
Further, Spirulina contains Phycocyanin which can only be found in Spirulina.