What is Active B12 1000 derived from? Emily April 01, 2019 17:16 Updated Follow The adenosylcobalamin and methylcobalamin are synthetic. Related articles What is Active B12 with L-5-MTHF derived from? Can Active B12 1000 be used for children? Potassium Deficiency Is Active B12 1000 suitable for vegans and vegetarians? If not, why? I am sensitive to folate. Is there anything I can do to help with the side effects when using L-5-MTHF Lozenges? Comments 0 comments Article is closed for comments.