Bruises are formed when a bang or a knock breaks capillaries, causing them to leak blood close to the skin's surface, forming an unsightly purple or brownish mark. Medical studies show that smoothing vitamin K cream onto the affected area can limit the leaking, reducing the severity of a bruise, particularly if applied soon after the trauma. Vitamin K cream has been shown to be even more effective if it also contains retinol. Gently rubbing the cream onto a bruise twice a day also helps to break down the blood and assist the body in absorbing it, encouraging the bruise to fade faster.

One of the most common beauty products to contain vitamin K is eye cream. Some dark circles are caused by fragile capillaries leaking blood in the delicate undereye area where the skin is so thin the blood is clearly visible in the form of brown bags. Gently tapping on a vitamin K cream can diminish the discoloration by causing the blood to clot, stopping it from spreading, while also helping to prevent further leakage. 

Healing after cosmetic surgery can often be a disappointingly long process. To help improve patient satisfaction, plastic surgeons have long prescribed vitamin K creams to reduce bruising and scarring during the recovery period. Applying the cream regularly for two weeks before facelift surgery can also help limit postoperative bruising. One medical study has shown topical application of vitamin K reduces bruising after facial laser treatments and would also be likely to help fade bruises caused by other nonsurgical treatments, such as the use of fillers on facial lines.

Many over-the-counter creams that claim to treat unsightly red veins contain vitamin K. The theory is that these thread, or spider, veins behave similarly to bruises because they are both caused by the pooling of blood from damaged blood vessels -- since vitamin K is known to reduce bruising, it should therefore also reduce thread veins.