Does anyone know if it is also true in Canada?

Yup. An enroute/terminal-approved IFR GPS can be
used to substitute for DME and ADF fixes during an
IFR approach in Canada. It's not anywhere in the
CARs, see your AIP. There was a "Supplement" that
came out in the last year or so that dealt specifically
with this issue, plus alternate planning.

The ONLY waypoints that can NOT be substituted by approved GPS in
Canada are NDBs and VORs used for Missed Approaches (i.e. you must
have an NDB or VOR as the case may be or request different missed
approach instructions). Weird but true.

A.I.P. 3.16.4.3.1. says "GPS may be used to identify all fixes defined
by DME, VOR, VOR/DME and NDB, including fixes that are part of any
IAP, to navigate to and from these fixes, ..." So far, so good. Next
paragraph: "For these approaches [NDB and VOR approaches without a GPS
overlay], and for approaches based on a LOC for lateral guidance,
pilots shall not use GPS for missed approach guidance when the missed
approach procedure requires tracking to or from an NDB or VOR."

Gerd
T182 C-FDOW