Calculus is not tested on the MCAT, as far as I know. You will not be asked to differentiate, or integrate (calculus procedures) any equations on the MCAT. However, Physics is absolutely crucial. Unless you were an EXTREMELY strong student in Physics in high school, I would take first year Physics over your humanities course.
On the MCAT, your Physical sciences section will draw roughly half of its questions from Physics, with the other half coming from Inorganic Chemistry. Physics is one of those animals that, unless you are intuitively numbers-minded, requires a great deal of repetition and practice to master. This is exactly what you'll get out of a first-year Physics course.
Also, most of the Ontario schools seem to use MCAT cut-offs quite stringently as a way of screening out applicants. This means that if you don't make a certain score in the Physical Sciences section, the Ontario school will reject your med school application on the spot, without even looking at your grades, and extra-curricular activities.
Take the Physics course. You'll probably hate it (I know I did :) ), but you'll be far better off in the end.