# New Paper - Vit D use and Covid Risk

**URL:** <https://forum.barbellmedicine.com/t/new-paper-vit-d-use-and-covid-risk/13005>\
**Category:** Medical Q&A \[Moderated\]\
**Created:** [November 20, 2022, 2:53pm UTC](https://forum.barbellmedicine.com/t/new-paper-vit-d-use-and-covid-risk/13005 "2022-11-20T14:53:13Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Limie](https://sea1.discourse-cdn.com/flex001/user_avatar/forum.barbellmedicine.com/limie/32/1432_2.png) [@Limie](https://forum.barbellmedicine.com/u/Limie)\
**Post date:** [November 20, 2022, 2:53pm UTC](https://forum.barbellmedicine.com/t/new-paper-vit-d-use-and-covid-risk/13005/1 "2022-11-20T14:53:13Z")

</div>

I saw this new paper in Nature Scientific Reports and thought I’d share it to get your perspective given your skepticism on the general value of Vit D supplementation

[https://www.nature.com/articles/s41598-022-24053-4#Sec19](https://www.nature.com/articles/s41598-022-24053-4#Sec19)

In short it’s a retrospective cohort study of people in the VA system comparing risk of covid infection and mortality between those who were Rxed Vit D vs those who were not. In their analysis, supplementation was associated with reduced risk of all outcomes, with the association being greater the higher the Vit D levels measured

Reasons for skepticism

- Rx does not actually mean supplementation
- They used a propensity matching approach to control for confounders that eliminated 340,000 controls from their analysis population (approx 80%). The more statistical fuckery employed, especially when not well described, the more dubious I am.
- One of the characteristics controlled for was Vit D deficiency. This means the supplementation (assuming Rx does equal supplementation) wasnt even addressing Vit D deficiency. In that context, I am not sure what supplementation is supposed to represent, but presumably could represent some sort of cohrt bias (are the people, regardless of Vit D status) who obtain Vit D from their VA doctor in some way different regarding health consciousness?  
​

---

<div class="post-metadata">

**Author:** ![Austin\_Baraki](https://sea1.discourse-cdn.com/flex001/user_avatar/forum.barbellmedicine.com/austin_baraki/32/1095_2.png) [@Austin\_Baraki](https://forum.barbellmedicine.com/u/Austin_Baraki)\
**Post date:** [November 20, 2022, 7:18pm UTC](https://forum.barbellmedicine.com/t/new-paper-vit-d-use-and-covid-risk/13005/2 "2022-11-20T19:18:53Z")

</div>

Yeah, these sorts of retrospective correlational studies can be hypothesis-generating for prospective randomized trials, but otherwise don’t really add anything to the conversation beyond what we’ve already discussed on our [Vit D podcast](https://soundcloud.com/user-344313169/vitamin-d-mixdown-1).