My doctor diagnosed me almost a year ago with "the worst case of acid reflux [she'd] ever seen." Literally, I would drink a glass of water and get reflux issues. I was put on Nexium for a long time, and I have since switched to Prilosec OTC because I ran out of health insurance. It's been about five days on Prilosec but I keep feeling nauseous in the morning after I take it, but it's nothing too bad and it goes away fairly quickly. I looked up the side effects today to see if the nausea was typical and discovered by accident that people on proton pump inhibitors tend to have much lower absorption of vitamin B12. So I dug around in my stepfather's vitamins and found liquid B12 and put it under my tongue like the instructions said and went about my day. Around two hours later, I ended up feeling extremely nauseous, weak, tired and dizzy, and nothing is helping any of those symptoms. When I got home, I took my pulse on my stepfather's blood pressure cuff and my pulse was at 85, and it's usually around 130. Is this a delayed reaction to the Prilosec, or is it the Prilosec with the B12? Thanks!!!