Identify the hidden meaning behind this picture?

What Deficiency does the below rebus represent?

VIT_MIN

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

You can see it everyday, But cannot touch it at will. What is it?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

When it's bad luck to meet a black cat?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

Detective Rockford was jogging near the beach at 4:30 am.
He hears a sound near the shack "No Michael, Please Do not shoot me".
Next instance he heard the sound of gunfire. Rockford rushes to the shack where he finds women lying dead and a gun in close proximity of three "Doctore Lawyer and a Teacher".

Rockford immediately knew that the Lawyer has committed the crime. How?