AUTHOR=Tondehal Nikhil Ravindranath , Hawa Saadiya , Malik Anem Sajid , Hamid Kazi Nadia , Malekunnel Ashley , Adnan Mahwish , Trivedi Chintan , Mansuri Zeeshan , Jain Shailesh TITLE=Commentary: Correlation analysis of serum vitamin D levels and post-operative cognitive disorder in elderly patients with gastrointestinal tumor JOURNAL=Frontiers in Psychiatry VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2022.971412 DOI=10.3389/fpsyt.2022.971412 ISSN=1664-0640