Regarding bruises : is it a problem forming a clot or problem with the skin? I get a bruise now and then, but I do not bleed anywhere.! also a vegetarian, no vitamins. 43f. Not pale, runner.

Easy bruising. Easy bruising without bleeding is very common esp in athletes/ runners. If otherwise healthy not to worry . If going to have elective surgery let the doctor know.
There are studies. This has been repeatedly studied in medicine. It is a very common question. When all else is normal these bruises come from minor trauma. The trauma was so minor most people do not remember. The bruise can take 72 hours to appear. I would say I have this question arise in my practice two or three times per month.