I recently stumbled upon this article: Neurodevelopmental Toxins Deplete Glutathione and Inhibit Folate and Vitamin B12-Dependent Methionine Synthase Activity: A Link between Oxidative Stress and Autism. (http://www.fasebj.org/cgi/content/meeting_abstract/22/1_MeetingAbstracts/894.1) I was wondering whether one would first have to do a serious heavy metal cleanse before embarking on the methylation protocol. Methylcobalamin injections, as well as other b-vitamins, folate etc will not work effectively without first treating heavy metals. It sounds reasonable that unless you get rid of the mercury and other heavy metals, it doesnt matter how much b12 you pump into your system it just will not reach your cells. I am not suggesting for one second that b vitamins should not be taken in conjunction with a chelation program as that would be unwise too. This brings me to my question on how one would start chelating safely. As Fred has mentioned many times on this forum Glutathione will eventually induce a b12 deficient state (I too have found this). I have also found this with the following supplements: glycine, glutamine, NAC, chlorella and recently dhea. Does anyone know whether DMSA, EDTA or Lipostabil (phospholipid exchange therapy) will have the same inducing effect? I look forward to hearing your views on this. Many thanks.