Usually they won't even heal you unless other party members (including themselves) are below 50 % health so be sure to bring a good amount of health items to each mission. (monstervine.com)
Other things you can do include using existing open databases for pedigree research on health items. (ashgi.org)
As with any non-traditional health items, apple cider vinegar should not replace regular medical care. (midwestmodernmomma.com)