Abstract: In order to provide our readers with timely access to new content, papers accepted by the American Journal of Tropical Medicine and Hygiene are posted online ahead of print publication. Papers that have been accepted for publication are peer-reviewed and copy edited but do not incorporate all corrections or constitute the final versions that will appear in the Journal. Final, corrected papers will be published online concurrent with the release of the print issue. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Am. J. Trop. Med. Hyg., 00(00), 2021, pp. 1–6 doi:10.4269/ajtmh.21-0577 Copyright © 2021 by The American Society of Tropical Medicine and Hygiene Evaluation of Vitamin-D Status and Its Association with Clinical Outcomes Among COVID-19 Patients in Pakistan Muhammad Sohaib Asghar,1* Farah Yasmin,2 Kartik Dapke,3 Syed Muhammad Ismail Shah,4 Muhammad Daim Bin Zafar,2 Anosh Aslam Khan,2 Osama Mohiuddin,2 and Salim Surani5 1 Department of Internal Medicine, Dow University of Health Sciences–Ojha Campus, Karachi, Pakistan; 2Department of Internal Medicine, Dow University of Health Sciences, Karachi, Pakistan; 3Indira Gandhi Government Medical College, Nagpur, India; 4Department of Internal Medicine, Ziauddin Medical University, Karachi, Pakistan; 5Adjunct Clinical Professor of Medicine and Pharmacology, Texas A&M University, College Station, Texas Abstract. The risk of acute respiratory tract infections is particularly pronounced in patients deficient in 25-hydroxyvitamin D (25(OH)D). With respect to COVID-19, there are conflicting evidence on the association of 25(OH)D levels with disease severity. We undertook this study to evaluate the 25(OH)D status in COVID-19 patients admitted in Karachi, Pakistan, and associated vitamin D deficiency with primary outcomes of mortality, length of stay, intubation, and frequency of COVID-19 symptoms. A total of 91 patients were evaluated for 25(OH)D status during their COVID-19 disease course. 25-hydroxyvitamin D levels were classified as deficient (, 10 ng/mL), insufficient (10–30 ng/mL), or sufficient (. 30 ng/mL). The study population comprised 68.1% males (N 5 62). The mean age was 52.6 6 15.7 years. Vitamin D deficiency was significantly associated with intensive care unit (ICU) admission (RR: 3.20; P 5 0.048), invasive ventilation (RR: 2.78; P 5 0.043), persistent pulmonary infiltrates (RR: 7.58; P , 0.001), and death (RR: 2.98; P , 0.001) on univariate Cox regression. On multivariate Cox regression, only death (RR: 2.13; P 5 0.046) and persistent pulmonary infiltrates (RR: 6.78; P 5 0.009) remained significant after adjustment for confounding factors. On Kaplan Meier curves, vitamin D deficient patients had persistent pulmonary infiltrates and a greater probability of requiring mechanical ventilation than patients with 25(OH)D $ 10 ng/mL. Mechanical ventilation had to be initiated early in the deficient group during the 30-day hospital stay (Chi-square: 4.565, P 5 0.033). Patients with 25(OH)D $ 10 ng/mL also demonstrated a higher probability of survival than those with 25(OH)D concentrations , 10 ng/mL. 25-hydroxyvitamin D deficient population had longer hospital stays and worse outcomes.