Effect of Vitamin D Supplementation on Covid-19 Mortality

by | Apr 1, 2025 | 2025, COVID-19, Recent Articles, Vitamin D - Infections & Immunity, Vitamins

Written by Jessica Patella, ND. High-dose vitamin D3 supplementation was shown to reduce mortality in hospitalized patients with COVID-19.

Covid-19 - maskThere have been over 7 million deaths worldwide due to COVID-191,2. Research has shown vitamin D3 supplementation improved mortality rates in hospitalized patients, but the best dosage was still unclear1.  Researchers therefore compared in-hospital mortality rates between patients that were treated the same, except one group that received 90,000 IU of vitamin D3.  Results of the research indicated high dosage vitamin D3 is safe and effective and may reduce mortality in COVID-19 infections1.

Multiple immune cells in the body (monocytes, dendritic cells, activated T cells) have receptors for vitamin D3. These receptors indicate vitamin D plays a role in immune functioning1.  Vitamin D has been shown to play a role in defending against HIV1, Rotavirus and Hepatitis C 1,4,5.

The current research was a retrospective analysis between December 2022 and April 2023 where patients diagnosed with COVID-19 (via rapid antigen test) in the emergency department were randomly selected to Department 1 or Department 2. All treatments used were the same, except patients in Department 1 received mandatory vitamin D3 on day 1 (30,000 IU/day for 3 days; followed by 3,000 IU per day during their hospital stay)1.

A total of 148 patients were randomly divided into the two departments.  Department 1 included 76 patients (average age 69 +/- 16 years) and Department 2 included 72 patients (average age 66 +/- 14 years).  The following results were observed1:

  • A total of 54 patients (36%) had a lab confirmed deficiency in vitamin D (25(OH)D < 20 ng/ mL). There was no significant difference in deficiency between the 2 departments.
  • Significantly fewer patients died in Department 1 where high dose vitamin D was supplemented compared to Department 2 (10 vs 29 respectively, p<0.01).
  • The high dose vitamin D patients in Department 1 had a reduction in mortality rate in the hospital by 67%.
  • Patients with vitamin D deficiency at admission (day 0) had significantly increased concentrations of 25(OH)D after supplementation on days 4 and 8 (p<0.01 for both days). Vitamin D concentration did not increase further during the 3000 IU/day supplementation.
  • The average value of 25(OH)D in vitamin D deficient patients increased from 11 ng/mL (day 0) to 27 ng/mL (day 8).
  • The average value of 25(OH)D in vitamin D non-deficient patients increased from 37 (day 0) to 45 ng/mL (day 8).

In conclusion, high-dose vitamin D3 supplementation was shown to reduce mortality in hospitalized patients with COVID-19. The researchers recommend dosing 30,000 IU of vitamin D3 for 3 days in hospitalized patients for COVID-19. The researchers found this to be a safe and effective dose.  The study was limited in the fact that it was a single-center, retrospective study1.

Source: Sümegi, Liza Dalma, Marina Varga, Veronika Kadocsa, Balázs Szili, Márk Stempler, Péter András Lakatos, Zsuzsanna Németh, and István Takács. “Effect of Moderately High-Dose Vitamin D3 Supplementation on Mortality in Patients Hospitalized for COVID-19 Infection.” Nutrients 17, no. 3 (2025): 507.

© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

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Posted April 1, 2025.

Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.

References:

  1. Sümegi, L.D.; et al. Effect of Moderately High-Dose Vitamin D3 Supplementation on

Mortality in Patients Hospitalized for COVID-19 Infection. Nutrients 2025, 17, 507. https://doi.org/10.3390/nu17030507

  1. Hewison M, et al. Differential regulation of vitamin D receptor and its ligand in human monocyte-derived dendritic cells.  Immunol. 2003, 170, 5382-5390.
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