The english word 'sanctify' has implications that are not suitable for Bible doctrine, so does repent. Repent or re-pennance has nothing to do with metanoia. Therefore both are related in that way.
So you know, if anyone asks to 'sanctify' anything it's automatically a point of humour.
Concerning, 1 Timothy 4:4-5.
The context had to do with food to be made clean/sanctified through prayer. Clean, as in "kosher." They had no concept of germs back then. The cleanliness spoken of food held a spiritual connotation. That is why sanctify was used.
People today who pray over junk food and think its now clean are going to reap what they sow because of their ignorance of what the Word was speaking about. Foods were considered clean and unclean according to religious standards, not health. Praying over bad food is going to lead to obesity and worse.