Yes, it is still necessary to report any Mutual Fund Capital Gains if no Schedule D is required. The Mutual Fund Capital Gains will go directly to your Form 1040 "Capital Gain or (Loss)" line if you don't have any other activity requiring a Schedule D.
Check out the TurboTax FAQ below for how to enter your Form 1099-DIV:
https://ttlc.intuit.com/replies/5646916
