[or your own] 

Read, and you will understand

Until today B12 Deficiency is often overlooked by doctors, even neurological departments!

Let’s summarize: anyone with unexplained symptoms [whatever they are] should be given a trial with vitamin B12.

Not doing so may cause irreversible damage.

https://www.peoplespharmacy.com/articles/curing-cracks-at-corners-of-the-mouth-saved-moms-life?utm_source=The%20People%27s%20Pharmacy%20Newsletter&utm_campaign=b9af8bbf3d-EMAIL_CAMPAIGN_2023_01_03_03_10&utm_medium=email&utm_term=0_7300006d3c-b9af8bbf3d-%5BLIST_EMAIL_ID%5D