Supplements with too much Vitamin A can be toxic to the liver since Vitamin A is a fat soluble vitamin (meaning more gets stored than excreted.) Sweet potatoes and other foods rich in Vitamin A, however, do not cause liver toxicity and can not be stored for long-term use like supplements can.
The wound healing stages are made up of three basic phases: inflammation, proliferation and maturation. There are many types of wounds that require different wound care products for proper recovery from an ulcer or laceration, but most go through similar healing stages.
Normally wound healing takes place over 3 stages which help your body to repair. These stages can be disrupted however by infection/ picking/ pulling at the wound this can cause problems either by stopping the wound from keeping healing or going back to a previous stage.