Vitamin D therapy in adults with diabetes mellitus

We read with interest the News and Views article by Joanna Mitri and Anastassios G.Pittas (Shining a light: the role of vitamin D in diabetes mellitus Nat. Rev. Endocrinol. 6, 478–480; 2010).¹ We fully agree on the utility of vitamin D supplementation in diabetes mellitus; however, we have an important observation on the author conclusions, in particular, in the Practice point box, concerning the suggested doses of vitamin D supplementation, it should be considered an important clinical point. We suppose that the authors are suggesting a supplementation with 25-hydroxycholecalciferol because in our clinical experience the doses of a supplementation with 1,25-dihydroxycholecalciferol that we can use in clinical practice are much lower, ranging between 0.5 μg to 1.5 μg daily, at maximum. We think that this aspect should be pointed out to avoid important mistakes by physicians.