What is Active B12 1000 derived from? Emily April 01, 2019 17:16 Updated Follow The adenosylcobalamin and methylcobalamin are synthetic. Related articles Can Active B12 1000 be used for children? Potassium Deficiency Is Active B12 1000 suitable for vegans and vegetarians? If not, why? What is the best form of vitamin B12 for someone who is histamine intolerant? 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.