Sorry, totally forgot to respond appropriately to this.

First, folate is actually vitamin B9 and not B12 (I have made that correction above). It also appears one does work for the other.

Then to your question, yes. B12 is found in mostly in meat and meat products (along with b9, anyways), so definitely, it follows logically that vegetarians may have issues with it.

Unfortunately, there are no enough data for other areas of world as far as neural tube defects are concerned. However, there are reports of around 500,000 cases global annual. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827875/