Did you enter all you deductions on your Federal return. TurboTax transfers data from your federal return to your state return.
Some federal itemized deductions are not allowed on the New York return. If your New York itemized deductions are less than your New York standard deduction, TurboTax will use standard deduction on your New York return.
Open you NY and continue until you get to the screen Let's Review Your New York Numbers to see it is using the standard deduction or itemized deductions.