AnnetteB
Intuit Alumni

Get your taxes done using TurboTax

Claiming the student loan interest deduction lowers your income amount.  If doing so resulted in a smaller refund, then you most likely are seeing a change in a tax credit that is calculated based on your income.  One example of this type of credit is the Earned Income Credit. 

There is not a requirement to claim the student loan interest on your tax return.  Generally it is beneficial to do so, but it is not mandatory.