Each serving of NB Pure Methyl B-12 Boost delivers 500 mcg of vitamin B-12. Methyl B-12 Boost spray features methylcobalamin, a highly bioavailable form of vitamin B-12. Vitamin B-12 plays a role in healthy nervous system and cardiovascular function and supplies the body with energy. Each 0.172 mL spray provides a potent 500 mcg vitamin B-12.