Well my blood test says I have high B12 levels. It also reveals that I have low Vitamin D but I've been taking Vitamin D regularly and noticed a slight improvement but not much as of yet. I do have digestion problems....food comes back up in my throat, have have acid reflux and heartburn regularly. What is UID? Didn't start gradually....comes and goes normally but it came again about 2months ago and didn't leave yet.