Vitamin D
Three patients with localized scleroderma were reported in 1940 to have improved following treatment with vitamin D2 [3] at a dose of 10,000–12,500 IU daily for one–three months. Perhaps due to the possibility of harmful effects from high-dose vitamin D2, that report did not garner much attention. The biologically active form of vitamin D, 1, 25-dihydroxycholecalciferol, or calcitriol, has been shown in multiple studies to be useful in treating scleroderma when taken orally. Calcitriol has a number of functions that may be seen to limit or reverse the course of the disease, such as immunoregulatory effects, growth inhibition of myoblasts, and collagen synthesis suppression.