I have read and understand that PPI's do cause B12 deficiency.

I guess each person is differnt and individual though, so it's really hard to say. I also believe you have to wait an hour after B12 before eating. I think taking only water with your B12 would be better also, but that's just cuz they say water is what all supplements and medications should be taken with.

Thankfully I learned to control my gerd with ACV and baking soda. I took nexium for 3 weeks but quit and when it acts up I do the ACV and baking soda 3 times a day, otherswise once a day for maintainence.

Hope you find what helps for you, I am still searching myself.