I know this will not be news to many of you but it was to me when I just read lithium is needed to transport B12 and folate into the cells. (See the attachment by Amy Yasko.) On hair analysis, my lithium levels were just about non-detectable (can't remember the exact number but extremely low). I started taking lithium orotate (Swanson brand, 5 mg.) several days ago and felt calmer that same night, and slept better. I was amazed. I also read in the below attachment that if lithium levels are low, and you take B12, it can deplete lithium even further. Lithium can be very calming (I can feel it!) I'm wondering if the negative reaction some people have to B12 and/or folate, stems from lithium depletion. Yasko talks about normalizing lithium levels before starting the methylation supplements. I know lithium can negatively affect the thyroid but this is a pretty low dose and I seem to need it. And also, very low lithium can be an indication of mercury problems, which I'm pretty sure I have. I'm doing the Quicksilver Mercury Tri Test in the very near future, plus 23andme, and hope to get some answers there as detoxing is always very hard for me.