My 1099-R box 15 includes premiums withheld for Health Benefits and Dental/Vision; in Turbo Tax, box 15 = Local Tax information. Where do I enter health premium data?

Health benefits do not belong on a 1099-R at all.    Boxes 15-17 are only for local taxes (rare).   Looks like the issuer of the 1099-R was trying to give you some additional information and used a unused box to put it in.    Leave boxes 15-17 blank.

The TurboTax Form 1099-R follows the IRS approved Form 1099-R. 

See IRS Form 1099-R - http://www.irs.gov/pub/irs-prior/f1099r--2016.pdf

Call the issuer for an explanation of what they are trying to inform you about.