Hi,
Thanks for asking.
Based on your query, my opinion is as follows.
1. Vegetarians commonly have Vit B12 deficiency, but not necessary always. Vit B12 in vegetarians is usually produced in gut by bacteria.
2. Also, green leafy vegetables are rich in Vit B12.
3. No, all of them are not connected.
ITP is secondary to viral infection and affects usually only platelets. It does not affect Vit B12, neither does
morphea.
4. Additionally, during deficiency, you can take Vit B12 supplements or injections, which will rapidly improve it.
Pernicious anemia will require evaluation, if vit B12 does not get corrected after taking oral Vit B12 for a long time.
Hope it helps.
Any further queries, happy to help again.