key: cord-0883570-ryzwdqos
authors: Khalili, Farnaz; Yarani, Reza; Haghgoo, Seyyed Mortaza; Emami Aleagha, Mohammad Sajad
title: Letter to Editor in response to the article “Vitamin D insufficiency as a potential culprit in critical COVID‐19 patients”
date: 2021-03-03
journal: J Med Virol
DOI: 10.1002/jmv.26912
sha: 7cc4c769af9334571c7b578a210e5f25121b20cd
doc_id: 883570
cord_uid: ryzwdqos

We carefully read the meta‐analysis article on the association between serum vitamin D status and outcome of COVID‐19 by Munshi et al. This article is protected by copyright. All rights reserved.

We carefully read the meta-analysis article on the association between serum vitamin D status and outcome of COVID-19 by Munshi et al. 1 

Vitamin D insufficiency as a potential culprit in critical COVID-19 patients

Measurement of vitamin D status: background, clinical use, and methodologies

Vitamin D assays in clinical laboratory: Past, present and future challenges

The determination of circulating 25-hydroxyvitamin D: no easy task

Current assays to determine free 25-hydroxyvitamin D in serum

Measurement of 25-hydroxyvitamin D in the clinical laboratory: current procedures, performance characteristics and limitations

 It is a sensitive and specific method. 6 -In some cases it has acceptable performance in the healthy individuals and in the vitamin D3supplemented patients, but the performance is unacceptable in patients who receive vitamin D2supplements. - 

 Can detect 25OH-Vit D2 and D3 separately.  Minimizes the interferences and matrix effects.  It is considered as a goldstandard method.  High sensitivity, specificity and repeatability. 3, 8, 9 -Time consuming and low throughput. 3,7 -A common problem with LC-MS/MS is its relative inability to discriminate between 25OH-Vit D3 and its inactive isomer 3-epi-25OH-Vit D3 which causes overestimation of total concentration of vitamin D. 3, 8, 9