Has marijuana been proven to delay or harm the healing of fractured bones? Even if it is consumed through food or via a vaporizer?

Likely helps healing. Not only has marijuana not been proven to delay the healing of fractures but recent research shows stimulation of the cannabinoid receptors reduces bone loss and stimulates bone formation in animals. While more research is needed, the current science suggests marijuana likely speeds the healing of fractures. See http://norml.Org/library/item/osteoporosis.