Being a new parent, I realized this is one thing I have failed at in my 20s with my parents. Should have definitely called them more often, even if it's just for a few minutes here and there.
Calling them every week at least once to see the nephew (we live in a different country ) - but I'll try to do the 1 minute a day I commented earlier.
It sounds like you don't have this chance anymore. . sorry for your loss.