Hacker News Reader

Comment by mulvya | Hacker News Reader

The study did not actually measure Vitamin D levels.

" But further investigation was needed because observational studies couldn’t establish a causal link between blood vitamin D levels and COVID-19. The challenge in establishing a causal link arises because blood vitamin D levels are influenced by multiple factors including genetics, exposure to sunlight, diet and supplements, and are associated with other risk factors for COVID-19, the researchers said.

“We were trying to get at the part of the variation in vitamin D that’s genetic and leave aside the rest to see whether or not there’s an association with the risk of getting COVID-19,” Cassano said. “And when we do it that way, we find no association, and that’s telling.”"

This was covered in early access here: https://www.reddit.com/r/COVID19/comments/kzy3bb/no_evidence...

View on HN

Yeah, as I was reading this, I couldn't help but wonder if genetic markers are sufficient to estimate vitamin D levels alone. Honestly the title of the article should be something like "Genetic markers of increased vitamin D levels do not correlate to lower severity of Covid-19"

From the paper:

> Genome-wide association studies (GWAS) of serum vitamin D levels identified genetic variants that are robustly associated with serum vitamin D status in different populations and ancestries.

Edit: thanks for both the replies below. I just wanted to answer the question about whether genetic markers are predictive, but I see now that leaving it at just that would be misleading.

"This study was not designed to evaluate the effect of acute changes in vitamin D status (ie, from supplementation) on prevention or treatment of COVID-19. One randomised trial and one quasi-experimental trial have provided evidence for a positive effect of vitamin D supplementation around time of diagnosis on COVID-19 prognosis in infected individuals. The doses of vitamin D administered in these studies could result in an acute change in the availability of vitamin D, which may support the immune system’s response to the virus, mitigate acute lung injury and contribute to improved prognosis. Our results, which pertain to long-term vitamin D status, do not preclude the possibility that therapeutic doses of vitamin D may be effective in preventing or treating COVID-19 infection. Larger randomised trials using diverse sample populations are needed to investigate the potential use of therapeutic doses of vitamin D supplementation for COVID-19 prevention and treatment."

The overall estimate of heritability of 25-hydroxyvitamin D serum concentrations attributable to GWAS common SNPs is 7.5%

from

https://www.nature.com/articles/s41467-017-02662-2

Thanks, Reddit is my go to place to find scientific evidence!

Reply on news.ycombinator.com