I'm not sure if you can still deduct that with the new limitations starting in 2018. Otherwise you get the loss by having less income to report when you take a distribution. @dmertz
But the rule before 2018 was.....
If this was your ONLY IRA and you closed it AND did NOT take the tax deduction for your contributions you may be able to claim some of the loss.
If you have a loss on your traditional IRA investment, you can recognize (include) the loss on your income tax return, but only when all the amounts in all your traditional IRA accounts have been distributed to you and the total distributions are less than your unrecovered basis, if any.
Your basis is the total amount of the nondeductible contributions in your traditional IRAs.
