Abbas Aflatoonian - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Farideh Arabjahvani - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Maryam Eftekhar - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Mozhgan Sayadi - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

The authors have been informed that some errors occurred on their published article entitled "Effect of vitamin D insufficiency treatment on fertility outcomes in frozen-thawed embryo transfer cycles: A randomized clinical trial" [Iran J Reprod Med ۲۰۱۴; ۱۲: ۵۹۵-۶۰۰] in the time of study and the tables which do not affect the article's conclusion. The completion date of the investigation was changed from April ۲۰۱۴ to February ۲۰۱۴. Also, the study results were re-analyzed, and some minor modifications were made in the numbers mentioned in the tables without affecting the overall meaning and concept of the study. The author's wishe to apologize for these errors. The online version of the article has been updated on ۱۲ June ۲۰۱۷ and can be found at http://dx.doi.org/۱۰.۱۸۵۰۲/ijrm.v۱۷i۱۲.۵۸۰۱