Add vertical space between links in a navigation menu?

Hello I am making a website that has a navigation menu on the left side and the links are working and placed as they should but they are way too close to each other!! :confused:
I want space between each link but I don't know how to do it I have googled but can find nothing helpful so maybe somebody here understands what vertical means.

Right now my list is like

Link 1
Link 2
Link 3

While I would want something more like
Link 1


Link 2


Link 3

My links are also in the form of buttons so they are not just normal links.
I do not want to add space to either side of the links I want to add space UNDER each link... just to clarify. Thank you.