How much vitamin D is optimal to take? Part 5 of a series

Vitamin D is indisputably the best early defense against COVID. Here's why.

Endemic vitamin D deficiency is widespread in many countries, [1] especially among seniors in nursing homes, [2] dating from before the COVID phenomenon.  Non-equatorial populations have less vitamin D available in the winter. [3]  Winter presents a trifecta of vitamin D challenges:  First, there are fewer hours of sunlight.  Second the sun is lower in the sky, its rays not so direct on the skin as during summer.  Third, we bundle up against cold weather, leaving minimal skin exposed while outdoors.  All of these reduce opportunity to begin vitamin D production in the skin.  Mask wearing further reduces exposed skin available for vitamin D production.

Therefore, during a time of low availability of sunlight for endogenous vitamin D production, it is likely prudent to supplement this nutrient.  Single bolus dosing of vitamin D3 did not help hospitalized patients with severe COVID. [4]  However, in a double-blind trial, when patients who were hospitalized with acute COVID received 3 or more doses of calcifediol (25-OH vitamin D, which is a pre-cursor to the active form 1,25-OH vitamin D3), the need for intensive care treatment was significantly reduced to only one of 50 patients, and none in the treatment group died, whereas half of the control patients were admitted to intensive care. [5]  Vitamin D supplementation reduced inflammatory markers in COVID patients. [6]

Vitamin D is a fat-soluble vitamin, and therefore not so quickly metabolized and excreted from the body as water soluble vitamins, such as the B family and C vitamins.  Still, regular supplementation seems to be more effective than seldom boluses.  In one study, an enormous initial dose of 200,000 IU, followed by 100,000 IU once per month, resulted in no decrease of severity or incidence of respiratory infections than the control group. [7]  In contrast, to such seldom dosing, daily dosing of vitamin D was associated with better outcomes against Influenza A [8] and other respiratory infections, even as low as 400 IU/day to 2000 IU/day, as in this meta-analysis. [9] 800 IU Vitamin D3 has been associated with decreased incidence of bone fracture. [10]   Such doses are generally considered to be unacceptably low doses among naturopathic physicians, and too low generally to be effective against viral infections such as COVID. 

Vitamin D has a long history of beneficial effect against cancer.  In the author’s cancer clinic, 15 years of daily direct contact with and clinical treatment of cancer patients has relied on daily dosing of 8,000 to 10,000 units of vitamin D3, and has been correlated, among use of many other nutrients, with extraordinary success in both remission from cancer and lack of cancer recurrence. [11]   No signs of intolerance of vitamin D3, nor of hyper-vitaminosis of vitamin D or hypercalcemia (that wasn’t already associated with osseous metastases or with hyperparathyroidism) has been seen in the clinic over those 15 years.  Therefore, my colleagues and I have generally considered this to be a safe and effective dose for ourselves as well, and we have often taken that daily dose also, though generally not so consistently as our cancer patients.  Since the research and writing of this five-part series, beginning over a year ago, cancer patients and I have started taking 14,000 units per day.

Even at supplementation of 20,000 IU per day of vitamin D3, it was found that Canadian adults had no evidence of vitamin D toxicity. [12]  Toxicity that was associated with vitamin D supplementation was found to be extremely rare, and in each case to be accompanied by calcium supplementation. [13] [14] 

Supplementation of vitamin D was significantly associated with lower rates of COVID cases in univariate analysis, [15]  but not multivariate analysis. [16]  The sample size was 349,598 participants with known baseline vitamin D levels, compiled from years earlier. 

How urgent is it for people all over the world to have access to sufficient vitamin D?

Much of the western hemisphere, and people in countries throughout the world have been traumatized by the COVID phenomenon, with fear of death and consequent behaviors from that fear rivalling and likely surpassing the pathogenicity of the associated SARS-CoV-2 virus.  Populations across the world have submitted to the extraordinary measures imposed by their governments to attempt to thwart the feared pandemic.  These efforts have largely failed for reasons given in Part 2 of my book, The Defeat Of COVID.

Vitamin D, on the other hand, might be called a Godsend by some, and should be recognized by now as a necessary nutrient for immune function, and a specifically useful and decisive one in defeating COVID, as we see study after study through this series of articles, from small to enormous, showing --  not just significantly – but drastically improved outcomes for those who supplement vitamin D before and during their experience with COVID.  To achieve adequate vitamin D levels, particularly during fall, winter and spring, when seasonal respiratory viruses are most active, supplementation is highly recommended for everyone.

Vitamin D supplementation should be kept in adequate supply in every household, especially when moving into winter, and to be sure there is enough for daily use for every household member, as an easy preventive measure, with no known drawback to daily use.  The urgency of such widespread vitamin D availability and storage, particularly for the COVID era, cannot be overemphasized, and epidemiologist Hermann Brenner makes a strong case for it here. [17]

It would be quite difficult for a person with adequate serum vitamin D levels to die of COVID.  How difficult is it? 

Mayo Clinic found “Among patients admitted with laboratory-confirmed COVID, 25 (OH) D levels were inversely associated with in-hospital mortality and the need for invasive mechanical ventilation.” [18]  In this study of 120 already severe cases of COVID in Algeria, it was also found that those with the lowest vitamin D levels were the most likely to die with a COVID diagnosis. [19]  Here is their graph of that correlation.

© S Bennouar, A Cherif, et al.

At this writing, the world population is 7,940,065,381 and the number of deaths attributed to COVID is 6,210,759.  [20] Therefore, 0.0007822, which is about 0.078% of the world’s citizens, or about 8 of every 10,000 people, have been alleged to die from COVID.  Considering that even among those with diagnosis of severe COVID illness, represented in the above graph, only 13.3% of those with the modest, and still quite low, 25(OH) vitamin D level of > 30 mcg/l died with a COVID diagnosis, and the other 86.7% survived, then it is exceedingly difficult to die of COVID with adequate vitamin D levels.

Studies from all over the world show significantly and overwhelmingly lower rates of death in COVID patients with adequate vitamin D levels.  Here is a visual representation of those linked, mostly peer-reviewed, studies from the compendium site https://c19vitamind.com.  All of the studies shown in the list below are of diagnosed and hospitalized patients with a diagnosis of COVID.

A diagnosis of COVID, currently defined by governments and media as a “case,” whether sick or well, is already shown in the studies above to be rare with adequate vitamin D levels. [21]  [22] [23] [24]  Symptomatic expression of COVID is still less likely with adequate Vitamin D levels. [25]  Hospitalization and mortality with COVID patients has been found to be significantly lower among those with adequate serum vitamin D levels. [26] [27] [28]   Each of these studies examined different serum levels of vitamin D among people in different parts of the world, with varying access to sunlight, with or without dosing of vitamin D, and with varying intervals of dosing.  The data taken together, however, make a strong case for the difficulty of actually dying of COVID while maintaining adequate vitamin D levels.  The serum levels observed in the studies cited herein rarely reached into >70 ng/ml.  The likelihood of dying from COVID while maintaining vitamin D levels above this level seems to be vanishingly small if not impossible.

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[1] K Cashman, K Dowling, et al.  Vitamin D deficiency in Europe: Pandemic?  Am J Clin Nutr Feb 10 2016.  103 (4).  1033-1044.  https://academic.oup.com/ajcn/article/103/4/1033/4662891

[2] T Griffin, D Wall, et al.  Vitamin D status of adults in the community, in outpatient clinics, in hospital, and in nursing homes in the west of Ireland.  J Gerontol. 75 (12).  Dec 2020.  2418-2425.  https://academic.oup.com/biomedgerontology/article-abstract/75/12/2418/5703038?redirectedFrom=fulltext

[3] T Clemens, J Adams, et al.  Measurement of circulating vitamin D in man.  Clin Chim Acta.  Jun 3 1982.  121 (3).  301-308.  https://pubmed.ncbi.nlm.nih.gov/6286167/

[4] I Murai, A Fernandes, et al.  Effect of a single high dose of vitamin D3 on hospital length of stay in patients with moderate to severe COVID-19: A randomized clinical trial.  JAMA.  Feb 17 2021.  e2026848.   https://pubmed.ncbi.nlm.nih.gov/33595634/

[5] M Entrenas L Entrenas, et al.  Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study.  J Steroid Biochem Mol Biol.  Oct 2020.  203:105751.  https://pubmed.ncbi.nlm.nih.gov/32871238/

[6] M Lakireddy, S Gadiga, et al.  Impact of pulse D therapy on the inflammatory markers in patients with COVID-19.  Research Square.  Feb 23 2021.  https://www.researchsquare.com/article/rs-152494/v1

[7] D Murdoch, S Slow et al.  Effect of vitamin D3 supplementation on upper respiratory tract infections in healthy adults: the Vidaris randomized controlled trial.  JAMA.  Sep 30 2012.  308 (13).  1333-1339.  https://europepmc.org/article/MED/23032549

[8] M Urashima, T Segawa, et al.  Randmized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren.  Am J Clin Nutr.  Mar 9 2010.  91 (5).  1255-1260.  https://europepmc.org/article/MED/20219962

[9] J Charan, J Goyal, et al.  Vitamin D for prevention of respiratory tract infections:  A systematic review and meta-analysis.  J Pharmacol & Pharmacotherapeutics.  Sep 30 2012.  3 (4).  300-303.  https://europepmc.org/article/PMC/3543548

[10] H Bischoff-Ferrari, W Willett, et al.  Fracture prevention with vitamin D supplementation.  JAMA.  May 11 2005.  https://jamanetwork.com/journals/jama/article-abstract/200871

[11] C Huber.  Defeating cancer requires more than one treatment method:  An 11-year retrospective case series using multiple nutritional and herbal agents, 2017 update.  Dec 30 2017.  https://natureworksbest.com/wp-content/uploads/2018/01/2017-Cancer-treatment-paper.2017.12.30.pdf

[12] J Ekwaru, J Zwicker, et al.  The importance of body weight for the dose response relationship of oral vitamin D supplementation and serum 25-hydroxyvitamin D in healthy volunteers.  PLoS One.  Nov 5 2014.  https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111265

[13] C Jacobus, M Holick, et al.  Hypervitaminosis D associated with drinking milk.  NEJM. Apr 30 1992.  326:  1173-1177.  https://www.nejm.org/doi/full/10.1056/NEJM199204303261801

[14] IOM (Institute of Medicine) Dietary Reference Intakes for Calcium and Vitamin D.  Washington, DC: National Academies Press.  2011. 

[15] C Hastie, D Mackay, et al.  Vitamin D concentrations and COVID-19 infection in UK Biobank.  Diab & Metab Syndrome: Clin Res Rev.  14 (4).  Jul – Aug 2020.  561-565. https://www.sciencedirect.com/science/article/abs/pii/S1871402120301156?via%3Dihub

[16] H Ma, T Zhou, et al.  Habitual use of vitamin D supplements and risk of coronavirus disease 2019 (COVID-19) infection a prospective study in UK Biobank.  Am J Clin Nutr.  Jan 29 2021.  https://academic.oup.com/ajcn/advance-article/doi/10.1093/ajcn/nqaa381/6123965

[17] H Brenner.  Vitamin D supplementation to prevent COVID-19 infections and deaths – accumulating evidence from epidemiological and intervention studies calls for immediate action.  Nutrients.  Dec 28 2020.  13 (2).  411.  https://www.mdpi.com/2072-6643/13/2/411/htm#B27-nutrients-13-00411

[18] A Angelidi, M Belanger, et al.  Vitamin D status is associated with in-hospital mortality and mechanical ventilation: A cohort of COVID-19 hospitalized patients. Jan 9 2021. Preprint. Mayo Clin Proc. https://www.sciencedirect.com/science/article/pii/S002561962100001X

[19] S Bennouar, A Cherif, et al.  Vitamin D deficiency and low serum calcium as predictors of poor prognosis in patients with severe COVID-19.  J Am Coll Nutr.  Nov 22 2020.  40. 104-110.  https://www.tandfonline.com/doi/full/10.1080/07315724.2020.1856013

[20] Worldometers.info. Apr 13 2022. https://www.worldometers.info/world-population/

[21] A D’Avolio, V Avataneo, et al.  25-hydroxyvitamin D concentrations are lower in patients with positive PCR for SARS-CoV-2.  Nutrients. Apr 20 2020. 12 (5).  https://www.mdpi.com/2072-6643/12/5/1359

[22] M Demir, F Demir, et al.  Vitamin D deficiency is associated with COVID-19 positivity and severity of the disease. J Med Vir.  Jan 29 2021.  https://onlinelibrary.wiley.com/doi/10.1002/jmv.26832

[23] A Abdollahi, H Sarvestani, et al.  The association between the level of serum 25(OH) vitamin D, obesity and underlying diseases with the risk of developing COVID-19 infection: A case-control study of hospitalized patients in Tehran, Iran.  J Med Virol.  Dec 12 2020.  https://onlinelibrary.wiley.com/doi/10.1002/jmv.26726

[24] A Faniyi, S Lugg, et al.  Vitamin D status and seroconversion for COVID-19 in UK healthcare workers.  Eur. Respir J 2020.  https://erj.ersjournals.com/content/erj/early/2020/11/26/13993003.04234-2020.full.pdf

[25] A Jain, R Chaurasia, et al.  Analysis of vitamin D level among asymptomatic and critically ill COVID-19 patients and its correlation with inflammatory markers.  Sci Rep.  Nov 19 2020.  10 (1) 20191.  https://pubmed.ncbi.nlm.nih.gov/33214648/

[26] A Radujkovic, T Hippchen.  Vitamin D deficiency and outcome of COVID-19 patients.  Nutrients. Aug 9 2020.  12 (9). 2757.  https://www.mdpi.com/2072-6643/12/9/2757/htm

[27] H Susianti, C Wahono, et al.  Low levels of vitamin D were associated with coagulopathy among hospitalized coronavirus (COVID-19) patients: a single-centered study in Indonesia.  J Med Biochem  Feb 12 2021.  https://aseestant.ceon.rs/index.php/jomb/article/view/30228

[28] M Infante, A Buoso, et al.  Low vitamin D status at admission as a risk factor for poor survival in hospitalized patients with COVID-19: An Italian retrospective study.  J Am Coll Nutrition.  Oct 31 2020.  https://www.tandfonline.com/doi/full/10.1080/07315724.2021.1877580