COVID-19 death 40 percent less likely if supplemented with Vitamin D and got above 30 ng (Spain 108,000 people)

Created July 2021

Vitamin D supplementation and COVID-19 risk: a population-based, cohort study

Journal of Endocrinological Investigation (2021) https://doi.org/10.1007/s40618-021-01639-9

J. Oristrell, J. C. Oliva, E. Casado, I. Subirana, D. Domínguez, A. Toloba, A. Balado & M. Grau

Subset of a table in PDF

Supplemented with cholecalciferol or calcifediol Other studies have found that Vitamin D levels >40 ng are even better, especially when achieved via non-daily or loading dosing 1. COVID-19 treated by Vitamin D - studies, reports, videos * {include} 1. Pages in both VitaminDWiki categories Virus and Calcidiol (calcifediol): {category}

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Purpose

To analyze the associations between cholecalciferol or calcifediol supplementation, serum 25-hydroxyvitamin D (25OHD) levels and COVID-19 outcomes in a large population.

Methods

All individuals ≥ 18 years old living in Barcelona-Central Catalonia (n = 4.6 million) supplemented with cholecalciferol or calcifediol from April 2019 to February 2020 were compared with propensity score-matched untreated controls. Outcome variables were SARS-CoV2 infection, severe COVID-19 and COVID-19 mortality occuring during the first wave of the pandemic. Demographical data, comorbidities, serum 25OHD levels and concomitant pharmacological treatments were collected as covariates. Associations between cholecalciferol or calcifediol use and outcome variables were analyzed using multivariate Cox proportional regression.

Results

Cholecalciferol supplementation (n = 108,343) was associated with slight protection from SARS-CoV2 infection (n = 4352 [4.0%] vs 9142/216,686 [4.2%] in controls; HR 0.95 [CI 95% 0.91–0.98], p = 0.004). Patients on cholecalciferol treatment achieving 25OHD levels ≥ 30 ng/ml had lower risk of SARS-CoV2 infection, lower risk of severe COVID-19 and lower COVID-19 mortality than unsupplemented 25OHD-deficient patients (56/9474 [0.6%] vs 96/7616 [1.3%]; HR 0.66 [CI 95% 0.46–0.93], p = 0.018).

Calcifediol use (n = 134,703) was not associated with reduced risk of SARS-CoV2 infection or mortality in the whole cohort.

However, patients on calcifediol treatment achieving serum 25OHD levels ≥ 30 ng/ml also had lower risk of SARS-CoV2 infection, lower risk of severe COVID-19, and lower COVID-19 mortality compared to 25OHD-deficient patients not receiving vitamin D supplements (88/16276 [0.5%] vs 96/7616 [1.3%]; HR 0.56 [CI 95% 0.42–0.76], p < 0.001).

Conclusions

In this large, population-based study, we observed that patients supplemented with cholecalciferol or calcifediol achieving serum 25OHD levels ≥ 30 ng/ml were associated with better COVID-19 outcomes.

Comment by Robin W - July 18

This is an observational study with no real control group. The artificially selected controls include people who are supplementing D3 without a prescription. Only those supplementing vitamin D (D3 I guess, but maybe D2) due to a prescription are in the D3 supplementation group.

Likewise the calcifediol supplementation group - and they are only included if they had a creatinine test, which makes me think that most or all of them are being treated for chronic kidney disease.

The calcifediol supplementation group has an average age of 70 and 85% of them are women.

The artificially constructed control group matches those individuals other characteristics as much as possible - the only difference being that they are not being prescribed calcifediol. But some of them will be supplementing D3 or perhaps D2 without prescription - possibly at decent levels rather than the lower intakes many doctors are likely to prescribe. Also, I guess this artificial control group probably contains lots of people with chronic kidney disease.

There may well be some useful observations about 25OHD levels and disease severity, but we already have such observations.

Tags: Calcidiol Virus