Against my better judgement, I decided to follow the advice of my GP. After finding my B12 to be 205 (mma 0.38, I think), she recommended 2 weeks of 100mcg b12 (no specifications of type/method) and then simply the RDA. We suspected the low levels were due to a nearly vegan diet for 20 years. I started with liquid cyano, then after researching, switched to sublingual methyl, which I couldn't tolerate. So, I tried a sublingual dibencozide b complex and tolerated it ok. After getting several weeks of at least 100mcg/day (+ a daily whole foods vitamin with A, C, and E), I went to drop down to the RDA and wasn't sure how to get the correct amount using a B complex, so I switched to sublingual hydroxyb12 and broke off a little chunk (more than the RDA, maybe 25 mcg if I had to guess) and have been taking that daily for awhile. It's now 3 months later and my level came back lower, at 157. Obviously I need higher dosage, and am frustrated that my GP wouldn't retest me sooner. So, I have two questions: 1. With a sublingual dosage of any sort/dosage, is it odd that my level dropped this much in 3 months? Though I'm not surprised it didn't raise it, I thought having a daily sublingual intake of some sort would at least keep the level stable. 2. Can vitamin C interfere with absorption? I read this somewhere and (since fruit is one of a handful of things that my stomach will tolerate) I often followed my B12 shortly after with orange juice or a smoothie. If anyone can shed light on either of these, it would be very appreciated!