Review the Research
Get summaries of key research on vitamin D and COVID-19
No association between vitamin D status and COVID-19 infection in São Paulo, Brazil.
Take Home Message
This retrospective study analyzed the data of 13,930 individuals >18 years of age in Sao Paulo, Brazil with RT-PCR results for SARS CoV-2 and serum 25(OH)D measurements within 30 days of the collection of the sample for COVID-19 RT-PCR test. There were no differences in the distribution of serum 25(OH)D values between the COVID-19 positive and negative groups [mean 25(OH)D of 28.8 ± 21.4 ng/mL (72 ± 53.5 nmol/l) vs 29.6 ± 18.1 ng/mL (74 ± 45.3 nmol/l) respectively]. The authors state that in the specific population studied, clinical, environmental, socioeconomic and cultural factors may have greater relevance than 25(OH)D in determining the susceptibility to COVID-19.
- No difference between the Detected and Not Detected groups were observed regarding the percentage of men and women, or regarding the age distribution. There was no significant difference for the mean serum 25(OH)D between men and women, or between younger adults and the elderly (>60 years) by t-test analysis.
- The Detected Group had a mean 25(OH)D of 28.8 ± 21.4 ng/mL (72 ±5 nmol/l), with a median of 26.0 ng/mL (65 nmol/l). The not Detected Group had a mean 25(OH)D of 29.6 ± 18.1 ng/mL (74 ± 45.3 nmol/l), with a median of 27.0 ng/mL (67.5 nmol/l).
- When the data was stratified using ranges of serum vitamin D concentrations, neither the percentage of individuals nor the means of serum 25(OH)D levels, were significantly different between the Detected and Not Detected groups. The ranges of the values were:
- < 12 ng/mL (<30 nmol/l) vitamin D [Detected=5.84%, mean=8.68 ng/ml (21.7 nmol/l) vs Not Detected= 5.79%, mean=9.01 ng/ml (22.5 nmol/l)]
- 12-20 ng/mL (30-50 nmol/l) vitamin D [Detected=19.1%, mean=15.83 ng/ml (39.6 nmol/l) vs Not Detected= 17.8%, mean=16.08 ng/ml (40.2 nmol/l)]
- 20-30 ng/mL (50-75 nmol/l) vitamin D [Detected=38.8%, mean=24.51 ng/ml (61.3 nmol/l) vs Not Detected= 37.2%, mean=24.6 ng/ml (61.5 nmol/l)], and
- > 30 ng/mL (> 75 nmol/l) vitamin D [Detected=36.2%, mean=43.4 ng/ml (108.5 nmol/l) vs Not Detected= 40.0%, mean=42.84 ng/ml (107.1 nmol/l)].
This study analyzed the data of 13,930 individuals in Sao Paulo, Brazil who underwent RT-PCR testing for the diagnosis of COVID-19 by a medical organization that provides supplemental health services and who also had serum 25(OH)D measurements. Men and women were represented equally, and the ages ranged from 18-90 years. The patients were divided into two groups: “Detected” or positive for COVID-19 (2345 patients) and “Not Detected” or negative for COVID-19 (11585 patients).
Things to Keep in Mind
- The authors stated that the population sample evaluated in this study has a high socioeconomic level, has access to private medical services, and is predominantly of Caucasian origin. Therefore, the authors were unable to assess socioeconomic or ethnic-racial factors that could affect infectivity.
- The pandemic spread in Brazil during late summer and early fall, periods characterized by higher levels of solar irradiation; therefore, low 25(OH)D is less prevalent in the population sample.
- The data for other clinical risk parameters for COVID-19, such as weight, diabetes and other comorbidities were unavailable and, therefore, could not be assessed in multivariate analysis.
- Despite evidence described in the literature on the immunological action of vitamin D, the authors did not observe differences between 25(OH)D status and COVID-19 susceptibility in a large Brazilian population sample. The study population, both with and without SARS CoV-2 infection, has a lower prevalence of hypovitaminosis D, compared to that described in European or American populations, or even within specific population subgroups living in Sao Paulo, such as the elderly over 80, institutionalized or chronically ill patients.
In conclusion, clinical, environmental, socio-economic and cultural factors have greater relevance than vitamin D status in determining the susceptibility to SARS-CoV-2 infections in the population studied.
- This retrospective study collected records from March to July 2020 for individuals of both genders, between 18 and 90 years old, with RT-PCR results for SARS CoV-2 and who simultaneously had their 25(OH)D measured over a period of 30 days before or after the collection of the sample for COVID-19 RT-PCR test.
- Data were collected from the Fleury Group’s Caché database. Fleury Group is a medical organization that provides supplemental health services in Brazil.
- In cases of patients with more than one vitamin D test, the most recent in relation to the RT-PCR date, was selected. Records with 25(OH)D above 100 ng/mL (250 nmol/l) were excluded to avoid distortions in the analysis of vitamin D averages.
- The resulting dataset included 13,930 patients that were divided into 2 groups: “Detected” or positive for COVID-19 (2345 patients) and “Not Detected” or negative for COVID-19 (11585 patients).
Brandão CMÁ, Chiamolera MI, Biscolla RPM, Lima JV Junior, De Francischi Ferrer CM, Prieto WH, de Sá Tavares Russo P, de Sá J, Dos Santos Lazari C, Granato CFH, Vieira JGH. No association between vitamin D status and COVID-19 infection in São Paulo, Brazil. Arch Endocrinol Metab. 2021 Mar 19:2359-3997000000343. doi: 10.20945/2359-3997000000343. Epub ahead of print. PMID: 33740339.