Where do you think it says your RMD is deductible?
RMD just means that you must withdraw a portion of your IRA each year (equal to or more than the required minimum amount). In other words, you can't leave your IRA untouched tax-free for your family to inherit, you must withdraw it and pay the income tax and use the money.
There is nothing special that makes an RMD tax-deductible, the whole point is you have to withdraw the money and pay the tax. In some cases, your IRA might be partly tax-free—if you invested non-deductible funds in a traditional IRA—but this would be true for all your IRA withdrawals, not just the RMD part. You will need to explain more what you are thinking.
