This research addressed vitamin d deficiency. review article The new engl and jour nal of medicine n engl j med 357;3 www.nejm.org july 19, 2007 Medical Progress Vitamin D Deficiency Michael F. Holick, M.D., Ph.D. These findings have important implications for understanding vitamin d in MS and improving patient outcomes. The results may inform clinical practice and guide development of more effective MS treatments. This work underscores the value of continued research in advancing MS care..