Good point, Rose, I think that's why it worries me so much that my paternal grandfather died of a heart attack (at an age 40 years younger than my Polish grandfather who gardened a lot). My paternal grandfather worked under stress most of the time.
I know I've often felt uncomfortable chest sensations.
I also know that I found a research paper linking something to do with the left ventricle to low B12.
I remember that when I looked at my heart test, I forget what it's called, that there was something a little out of the ordinary with my left... but the doctors said it wasn't important.
Which of course now reminds me of how Clinton had masses of tests that apparently the doctors didn't find anything important in, just before he had to have emergency heart surgery....
Plus, all the material linking homocysteine with B12... and heart problems.
There are just SO MANY reasons to take B12, preferably the Methylcobalamin form.