I am a newbie to this site and am very impressed with the support and information provided here and desperately seek some advice as I am at a crossroad. Just when it all seemed crystal clear, it's now clear as mud.... Research of my symptoms led me to believe that I would be an ideal candidate to benefit from the B12/methylation protocol . While continuing my research, I asked my doctor for a B12 test (already having had folate, B6 and full blood tested). I realised immediately after the B12 test that the test ordered was Serum B12 and not Active B12 and would be useless. So, back I went for Active B12 and homocysteine to be tested. In the meantime my own research continued and I was just about to order the critical and essential basics per Freddds protocol when my Active B12 results came in. In short, my Serum B12 was high (this was not unexpected as I was taking a B-complex 4x/week and the serum result would likely be mirroring the B12 (cyanocobalamin) in my blood but not providing Active B12 levels. A few days ago the Active B12 (HoloTC) result came in high at 128 (reference range 23-100 pmol/L). tHcy (homocysteine) = 9 umol/L (referance range 5-12 umol/L) RBC Folate = 2093 nmol/L (reference range 800 3000 nmol/L) Serum B12 = 740 pmol/L (reference range 200 700 pmol/L) I have not yet gone down the more extensive diagnostic testing route and have only had the standard blood tests above (plus full blood) through my GP. Q: Should I start on the methylation protocol anyway (based on a comment by Freddd Treating to specific test results appears to produce unreliable and poor results in the realm of b12 and folate testing including the indirct Hcy and MMA tests. Only trying both active b12s plus methylfolate can tell you if you will respond to one, two or three of them Or should I undergo further testing before starting methylation/B12? Advice desperately sought. Big thanks in advance.