Any concern with eating one 4 oz. Small can of tuna fish for lunch each day that contains 6 percent dv (20 mgs.) of chloresterol in each can?

Not likely,, I don't know what your cholesterol is but if you're eating this every day you're likely helping yourself as this is fish which have omega 3 fatty acids which are very good for your circulation and seem to help stop heart disease, etc.. It's also a good source of protein and calories, so keep it up and enjoy. Good luck.