No piece of income is taxed in isolation. If the IRA distribution was taxable on the Federal return (and it most likely was), it is already included in the Federal AGI that transferred to line 1 of Ohio form IT1040. There will be no separate entry for the IRA distribution on the Ohio tax forms.
If for some reason, it was not taxable on the federal return (e.g. qualified Roth IRA distribution), it is also not taxable on the Ohio return.
If you are actually retired, the distribution will probably qualify for Ohio's retirement income tax credit