I've been suffering with lightheadedness, weakness, fatigue, balance problems for about 6 months. No room-spinning vertigo, but a general sense of weakness and not being able to stand up for long before feeling wobbly. And generally feeling crap. I haven't actually collapsed or fallen. I've seen ENT and Cardiology and both are clear. I've been referred to Neuro but haven't been yet. Can't help but try and self-diagnose. I'm here because I recently became aware of a possible connection between long-term use of PPIs and B12 deficiency. I've been taking omeprazole for about 25years. I insisted on having my B12 tested recently and according to my GP it was "normal" - it was around 330. Any advice on where I go from here? Am I likely to be deficient despite my "normal" test?