"Indonesian study: Low Vitamin D patients ten times more likely to die of Coronavirus
"If this is confirmed, Coronavirus is almost a disease of Vitamin D deficiency
preprint via http://joannenova.com.au/
http://joannenova.com.au/2020/…to-help-beat-coronavirus/
"After controlling for known risk like being old, or male or having high blood pressure, a Vitamin D level described as deficient (less than 20ng/ml) was associated with a 10 fold greater risk of death. These are quite extraordinary numbers. In most medical studies an OR (odds ratio) as low as 1.3 is notable enough to get published. But these are OR’s of 10."
The devil as always is in the detail. A lot of the COVID studies suffer this same issue that makes the results worthless:
To determine the association of Vitamin D status and mortality outcome, all ORs were adjusted for age, sex, and comorbidity using a generalized linear model. A p-value less than 0.05 was considered statistically significant.
The deconfounding of the very strong age dependence will not work if dependence is treated linearly, because the dependence on age is:
(a) highly nonlinear
(b) very strong
And Vit D will correlate very strongly (and inversely) with age.
So, without checking the maths, or being sensible about what the maths means, you get garbage results.
They could take this data, generate age balanced buckets, look at the correlation with each bucket between vit D and mortality (doing the same linear deconfounding per bucket). Combine results. Within each bucket the dependence on age would be linear (if buckets were small enough - say 3 years). That would give more believable results.
Notwithstanding that it is a good call to make sure Vitamin D levels are high, not proven to help but mild evidence supporting the possibility:
https://www.mdpi.com/2072-6643/12/4/988
Several observational studies and clinical trials reported that vitamin D supplementation reduced the risk of influenza, whereas others did not. Evidence supporting the role of vitamin D in reducing risk of COVID-19 includes that the outbreak occurred in winter, a time when 25-hydroxyvitamin D (25(OH)D) concentrations are lowest; that the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome; and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. To reduce the risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40-60 ng/mL (100-150 nmol/L). For treatment of people who become infected with COVID-19, higher vitamin D3 doses might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations.
That is why it is a pity that observational studies are on this topic are not more carefully conducted! Having said that, the above (v poor) study is not on any of the main preprint servers, and published on a fringe site known for unreliablescience reporting.
if it gets posted on a preprint server it will get commented on severely. I guarantee.
THH