I have calcium deposits on my front 2 teeth & my dentist said should be gone when I'm adult- why aren't they?

I have calcium deposits, and my mom said that it was caused by lack of some vitamin when I was younger. It wasn't caused by too much calcium, she said. One of my dentists used some sort of tool to sc it off. It was like a polisher I believe. It looks much better now. I don't think they will go away on their own. Mine never change.