Vitamin D as an add-on therapy could provide some relief for chronic hives, a condition with no cure and few treatment options, new research indicates. An allergic skin condition, chronic hives create red, itchy welts on the skin and sometimes swelling. They can occur daily and last longer than six weeks, even years. The two-year study looked at the role of over-the-counter vitamin D3 as a supplemental treatment for chronic hives.