Hi all! I've tried to search through these forums to see if anyone has had a situation like mine... I'm hoping someone might have suggestions of where to start or what I should have tested. I'll try to include as much information as I can, without being too lengthy... (for reference, I'm a 33 year old female with normal weight at 114ish, 5'4''). In March 2013 I found out I was deficient in B12 (343) and Vitamin D (22). I was told to supplement with a sublingual and monthly injections for 3 months, and then they'd check to see if my levels changed. Well, not knowing there was a difference in B12's, I grabbed the Trader Joe's B12 sublingual and started that daily for a week prior to my first injection (both were cyanocobalamin). I had a handful of side-effects but didn't realize it was from the B12 until the second injection. It seemed crazy to me (and my Dr) that I never experienced any symptoms of low B12 until I started supplementing B12! Major fatigue, dry & itchy skin (that has now turned into hives all over my body), brain fog, dizziness, weak muscles, rapid heartbeat, extreme thirst. I declined the 3rd month of injections and did research while I waited for my bloodwork checkup. My levels went up to 552 for B12 and 54 for Vit D, so my Dr wasn't concerned with pursuing it further, and I decided to find a Multi Vitamin with methylcobalamin (I chose the NOW brand), and see if I slowly got better. A little bit of background, just in case it matters: I had been vegetarian from 2009 to near the end of 2012, and in Oct 2012 I abruptly changed my diet to paleo/primal (eating meat again and removing all grains, beans, sugars and most dairy). Other than totally out of whack menstrual cycles since 2008, prior to going paleo the only symptoms I felt were weight gain, horrible acne, crazy anxiety, unstable blood sugar levels. After adding meat back into my diet (and cutting out starches) a lot of these symptoms subsided. For the first 6 months of eating paleo I kind of felt amazing! I still had some hormonal acne, and also found out I had a uterine fibroid, which was removed late in 2013. It's been almost a year now (since the B12 injections) and I knew I was very, very slowly feeling less and less tired. I'd have a bad day here and there, but for the most part I was managing things. Against my best wishes I'm on an H-1 and H-2 (antihistamine) to manage the red skin/hives and itchiness, which has morphed and gotten worse since the B12 injections. I've sort of narrowed these issues down to a histamine intolerance (if anyone has experience in that), since meat (especially cured or left-over meats) are very high in histamines. I'm not sure if the cyanocobalamin brought this out or it was purely coincidence that it happened 6-9 months after starting to eat meat again. I'm finally posting on this forum, after months of looking around, because this week has been horrible! It feels like the first week after my injections, and I didn't realize I had been feeling so much better until I felt worse again. I've had a very stressful month, but other than that nothing has changed. I haven't changed any supplements or eating habits. I used to be very active (triathlons, regular runs and yoga) but since the fatigue from the cyanocobalamin over the last year I haven't been exercising nearly as much as I used to (which is a bit ok, I'm a woodworker and work on my feet 80% of the time), but now even standing up (or sitting down!) is exhausting. Months ago I tried experimenting with my diet, thinking maybe I wasn't getting enough carbs. I'd make sure I had a sweet potato with breakfast, and almost over-salt my food (I already like things salty). These two things seemed to help with the afternoon fatigue (this week, nothing has helped). Was that the potassium? I also generally have low blood pressure, usually 100-110/80. Before the B12 injections, potassium was at 4.0, folate at 18.3, thyroid (T4) was 1.07. My mother swears I have CFS... she had suffered from Epstein-Barr/Mono in the past, possibly CFS, and now has arthritis at 62. She also had her thyroid removed due to a benign tumor. My grandmother, her mother, has Fibromyalgia. I don't like thinking the cards are stacked against me, and want to make sure I'm taking care of things before they get worse. I've read through the B12 protocol and have a very simple understanding of it. I have a checkup with my Dr coming up... are there any tests I should request them to run? I have my online cart full of supplements, but I guess I'm waiting for... I don't know. Guidance from someone other than my somewhat less-than-helpful Doctor.