Originally Posted by mrsD

I personally don't think sublingual vs oral swallow is much of an issue. I don't believe that sublingual works very well. This form has historically been the favorite OTC version, but B12 is a huge molecule and water soluble and not likely to cross the small area under the tongue in reasonable amounts of time. What really happens is that the sublingual dissolves and the resultant saliva is swallowed. And what can happen is that the tablet kept under the tongue may irritate tissues over time, and cause inflammation in sensitive people or those reactive to flavors or sweeteners. If you want to dissolve your sublingual under the tongue fine, but I don't think you HAVE to.