Depends. If it's an onboard video card (one built into the motherboard) chances are it already does. Go through the BIOS at startup and allocate more or less shared memory as desired.
Otherwise, if you have a graphics card with dedicated memory, then you can't share memory from the ram sticks to the video card 'cuz although the ram sticks and video card both have "memory" but they're not the same thing (i.e., not compatible).