Unless you have a restricted diet, try boosting the Vitamin C in your diet. Like tomatoes, citrus fruits, berries, broccoli, spinach and other things rich in Vitamin C.
While no major deficiency was found (although I am mildly anemic), my doctor suggested I boost my Vitamin C (SPECIFICALLY with foods/drinks, not pills) to see if it helped with my bruising. I do fall a lot and run into things, most of my bruises are accounted for. After I started to make myself shakes and smoothies (using the fruits/veggies listed above) and I eat a few tomato slices throughout the day, I noticed less bruises and when I have them, they are less severe.
You should
ask your doctor first before trying this to make sure this would be OK for you.