Cobalt is an essential trace element and forms part of the active site of Vitamin B12. The amount of cobalt required in the human body is very small and it contains only about 1 mg. Cobalt salts in small doses have been found to be effective in correcting mineral deficiencies in certain animals. But in large doses it is carcinogenic. The radioactive isotope Cobalt 60 is sometimes used in some countries to irradiate food to preserve it. There are no established criteria limits for cobalt in medicinal plants[37]. Cobalt was not detected in this plant extract.