Kindly check https://www.uspharmacist.com/article/impact-of-vitamins-on-immune-function-in-covid19-patients

Also check https://clinicalmolecularallergy.biomedcentral.com/articles/10.1186/s12948-020-00139-0

Vitamin D has many mechanisms by which it reduces the risk of microbial infection and death, including physical barrier, cellular natural immunity, and adaptive immunity. Vitamin D supplementation has shown favorable effects in viral infections including influenza and HIV. The effects of vitamin D supplementation during covid 19 infection remain controversial. https://clinicalmolecularallergy.biomedcentral.com/articles/10.1186/s12948-020-00139-0

Also check https://royalsocietypublishing.org/doi/10.1098/rsos.201912

Deficiency of Vitamin D increases the risk of COVID-19.

https://www.news-medical.net/news/20200908/Vitamin-D-deficiency-can-increase-risk-of-COVID-19.aspx

https://www.healio.com/news/primary-care/20200908/vitamin-d-deficiency-may-increase-risk-for-covid19

Vitamin D deficiency increases the severity of COVID-19.

Article Vitamin D deficiency and co-morbidities in COVID-19 patients...

Preprint Effect of Vitamin D deficiency on COVID-19 status: A systematic review

Article Does Vitamin D deficiency increase the severity of COVID-19?

Dear Tareq Abdhilkadhim Naser Alasadi ,

This article maybe helpful for you.

https://www.maturitas.org/article/S0378-5122(20)30346-7/pdf

Regards,

Shafagat

There is clear scientific evidence to support that Vitamin D reduces COVID-19 infections, hospitalizations, and deaths.

https://www.nutraingredients.com/Article/2020/12/21/Experts-send-Vitamin-D-and-Covid-19-open-letter-to-world-s-governments

Article Vitamin D and Covid-19: an update on evidence and potential ...

Article Zinc, Vitamin D and Vitamin C: Perspectives for COVID-19 Wit...

https://www.uchealth.org/today/effectiveness-of-vitamins-c-and-d-against-covid-19/

To all respected friends and researchers ,thankyou for your answers ,here i add some of my files on vitamines and covid 19 ,

thanks for all peoples who answer my question here.

Dear Tareq Alasadi, please have a look at the following attached document entitled " Association of Vitamin D Status and Other Clinical Characteristics With COVID-19 Test Results "

Dear Tareq Alasadi, please have a look at the following attached document entitled "The Role of Vitamins on the Prevention and/or Treatment of COVID-19 Infection; a Systematic Review."

Dear Tareq Alasadi, the following attached document entitled, "Vitamin C and coronavirus." might be useful, please have a look.

This publication gives a nice overview of possible effects and associations of vitamin / minerals and COVID19. Remember, deficiency increases the risk and in those situations were the vitamin or mineral status is far from optimal, a significant effect may be seen upon supplementation.

https://www.sciencenews.org/article/coronavirus-covid-19-supplements-vitamins-what-we-know

Article Relation of vitamin D to COVID-19

Article Vitamin D and COVID-19: How Much Vitamin D Does a Man Need?

Of the vitamins and supplements that were studied, vitamin D presented the most promising data demonstrating significant decreases in oxygen requirements, need for ICU treatment, SARS-CoV-2 RNA test positivity, and mortality. All of these benefits were exhibited in hospitalized patients. Other vitamins and supplements that were evaluated in studies did not demonstrate any statistically significant benefits. Common shortcomings of the articles included generally small sample sizes, varying sites of study (which could determine the virus variant), a lack of standard of care as background therapy, and utilization of doses that were higher than standard.

Dear researchers ,thankyou all for your answers.

Also have a look at the following RG links for more insight.

Article Multi-Level Immune Support by Vitamins C and D during the SA...

Article Vitamin D’s Role in Reducing Risk of SARS-CoV-2 and COVID-19...

Article Association of vitamin D status with COVID-19 and its severi...

Article Pre-infection 25-hydroxyvitamin D3 levels and association wi...

The following study demonstrates that individual micronutrient supplementations, including vitamin C, vitamin D, and zinc, are not associated with a mortality benefit in COVID-19.

Article Clinical Significance of Micronutrient Supplements in Patien...

The following study also suggests no link between vitamin D supplements and reduced risk of COVID-19.

Article Effect of a test-and-treat approach to vitamin D supplementa...