Vitamin D and covid-19
BMJ 2021; 372 doi: https://doi.org/10.1136/bmj.n544 (Published 04 March 2021) Cite this as: BMJ 2021;372:n544Read our latest coverage of the coronavirus outbreak
All rapid responses
Dear Editor
In their editorial on vitamin D and covid-19, Vimaleswaran and colleagues repeat the claim that vitamin D has a modest protective effect against acute respiratory infection.[1] However, this claim does not withstand close scrutiny.
In the meta-analyses cited by the editorialists to support it,[2] the authors report risk estimates using odds ratios, which are misleading because the outcome is common.[3] In fact, using data from this meta-analysis, the relative risk reduction for vitamin D supplements in preventing acute respiratory infection is 0.97 (95%CI 0.95-1.00, P=0.049). Further, the authors of the meta-analysis noted the possibility of publication bias in favour of beneficial results for vitamin D and substantial heterogeneity in the results. In subgroup analyses exploring this heterogeneity, the purported benefits of vitamin D were confined to the trials conducted in children aged 1-16 years. In that subgroup, the relative risk was 0.91 (95%CI 0.84-0.98), with 2/15 trials reporting statistically significant reductions in risk. However, the trial with the most positive result[4] had a cluster design which was not accounted for in the meta-analysis;[3] its removal produces a pooled risk reduction that is no longer statistically significant. By contrast, in children aged 0-1 years, and in adults 16-64 and 65+ years, the relative risks were 0.96 to 0.99, the CIs included 1, and only 1/42 trials reported a statistically significant reduction in risk.
Even if vitamin D does have a very small protective benefit for respiratory infections, it is unwise to generalise results from a subgroup analysis in children to the broader population. While people can hope that benefits will emerge in trials of vitamin D in Covid-19 currently being undertaken, based on current evidence that hope is largely based on wishful thinking.
References
1. Vimaleswaran KS, Forouhi NG, Khunti K. Vitamin D and covid-19. BMJ 2021;372:n544.
2. Jolliffe DA, Camargo CA, Sluyter JD, et al. Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of aggregate data from randomised controlled trials. medRxiv 2020.
3. Bolland MJ, Avenell A. Incorrect and Misleading Claims Regarding Vitamin D. Ir Med J 2020;113(7):P145.
4. Camargo CA, Jr., Ganmaa D, Frazier AL, et al. Randomized trial of vitamin D supplementation and risk of acute respiratory infection in Mongolia. Pediatrics 2012;130(3):e561-7.
Competing interests: We have conducted systematic reviews of the effect of vitamin D, and have critically reviewed the evidence for effects of vitamin D on non-skeletal outcomes in several articles.
Dear Editor,
In their editorial Vimaleswaran et al call for more research linking vitamin D and Covid-19, despite a significant body of observational and trial data, a sound safety profile, overlapping risk factors for both vitamin D deficiency and severe Covid-19: older age, obesity and darker skin types, as well as higher winter and higher latitudinal prevalence.
In contrast, 220 international physicians, researchers and experts call for action now to improve the vitamin D status for the many vitamin D deficient populations: they signed an open letter in December 2020, stating the size of the vitamin D supplement they themselves take.(2)
Isn’t this the crucial point: advising an adequate effective dose capable to elevate serum 25-hydroxyvitamin D to effective levels for the important well-researched immune modulatory function of vitamin D, more pertinent in a pandemic, rather than for bone health? Not only has the UK guidance to take 400 IU been in existence for a while, but is also not well adhered to, as the authors rightly point out. In addition this small dose is insufficient even for just the bone health of a quarter of people in Scotland (3).
In this pandemic, has the time not come to act on the balance of probabilities, rather than claiming insufficient research in a gate keeping fashion?
(1) Vimaleswaran K S, Forouhi N G, Khunti K. Vitamin D and covid-19 BMJ 2021; 372 :n544 doi:10.1136/bmj.n544
(2) Over 200 Scientists & Doctors Call For Increased Vitamin D Use To Combat COVID-19. VitaminDforAll.org
(3) Zgaga L, Theodoratou E, Farrington SM, et al. Diet, environmental factors, and lifestyle underlie the high prevalence of vitamin D deficiency in healthy adults in Scotland, and supplementation reduces the proportion that are severely deficient. J Nutr. 2011;141(8):1535-1542. doi:10.3945/jn.111.140012
Competing interests: No competing interests
Dear Editor
Further to the editorial on Vitamin D and COVID-19 (1) the following points need consideration -
Prevention
The recent NICE guideline recommends a vitamin D3 dose of only 400 IU (10 micrograms) (2). This is for adults (and perhaps surprisingly also for infants from 1 year of age upwards). Recommendations for higher adult doses of 4000 IU (or at least 2000 IU) have been made by over 200 well known doctors and scientists to combat COVID-19.
Vitamin D toxicity from supplements is rare. It is associated with serum levels higher than 250 nmol/L. (3, 4). A daily dose of 4000 IU (100 micrograms) for three months will not result in levels anywhere near this figure and leaves a wide margin of safety. (5)
Vitamin D is a safe and inexpensive medication. A high incidence of vitamin D deficiency has been reported in the UK (6) and increases the risk of severe COVID-19 infection. The precautionary principle (briefly mentioned in the editorial) makes the point that lack of full scientific evidence does not preclude action if damage would be otherwise serious and irreversible.
Treatment
Significantly reduced severity of COVID-19 infection has been reported in a randomised controlled trial with a vitamin D derivative (calcifediol) rather than the usual form of vitamin D3 available in the UK (cholecalciferol) (7). Calcifediol is more rapidly effective, better absorbed and 3.2 times more active than cholecalciferol (8). Also, cholecalciferol may take over a week to be fully active and this may be too late for moderately or severely ill patients to respond to treatment. Shouldn’t calcifediol be used for treatment in the UK?
1. Vimaleswaran K S, Forouhi N G, Khunti K. Vitamin D and covid-19 BMJ 2021; 372 :n544 doi:10.1136/bmj.n544
2. NICE. Vitamin D for covid-19: evidence reviews for the use of vitamin D supplementation as prevention and treatment of covid-19. 2020. https://www.nice.org.uk/guidance/ng187/evidence/evidence-reviews-for-the...
3. Jones G. Pharmacokinetics of vitamin D toxicity The American Journal of Clinical Nutrition, Volume 88, Issue 2, August 2008, Pages 582S–586S, https://doi.org/10.1093/ajcn/88.2.582S
4. Vieth R Critique of the considerations for establishing the tolerable upper intake level for vitamin D: critical need for revision upwards. J Nutr 2006 Apr;136(4):1117-22. https://doi.org/10.1093/jn/136.4.1117
5. Vieth R, Chan PC, MacFarlane GD. Efficacy and safety of vitamin D3 intake exceeding the lowest observed adverse effect level Am J Clin Nutr 2001 Feb;73(2):288-94. doi: 10.1093/ajcn/73.2.288
6. Sutherland JP, Zhou A, Leach MJ, Hypp?nen E. Differences and determinants of vitamin D deficiency among UK biobank participants: A cross-ethnic and socioeconomic study. Clin Nutr. 2020 Nov 25;S0261-5614(20)30639-7 doi: 10.1016/j.clnu.2020.11.019
7. Entrenas Castillo M, Entrenas Costa LM, Vaquero Barrios JM, etal. 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 2020 ;203:105751. doi: 10.1016/j.jsbmb.2020.105751. pmid: 32871238
8. J. M. Quesada-Gomez & R. Bouillon Is calcifediol better than cholecalciferol for vitamin D supplementation? Osteoporosis International volume 29, pages1697–1711(2018)
Competing interests: No competing interests
Dear Editor,
We have seen 5 responses now in relation to the article that continues to advocate the UK dose of Vitamin D, all suggesting that as a nation we are using much too low a dose.
I have yet to see though any article or research that supplementing vitamin D at a higher dose makes any difference to anything, be it Covid, cancer, MS or even bone health - so we have an association and lots of opinions. If such data exists that supplementing Vitamin D pre covid in a higher dose makes a difference to catching it, getting ill or dying why are we not seeing it?
Other countries have other policies. Can these be shared and in terms of bone health (where as GPs we have been promoting calcium and vitamin D now for 25 years) has this been a waste of time? Should we be adding vitamin K2?
So many basic questions about everyday life and seemingly the answers are missing or we are to blind to see them - useless supplement or too low a dose?
Competing interests: No competing interests
Dear Editor
It is encouraging to read about promises of vitamin D in the fight against COVID-19. The task force of the NNEdPro group has called for almost a year to consider seasonal vitamin D deficiency as a public health emergency that is likely to contribute to the pandemic. Here we want to highlight a couple of points that sometimes get lost in the often contentious debate about the potential merits of supplemental vitamin D.
The first point is that vitamin D has an essential role in the function of innate immunity, the part of our antiviral defenses that acts before antibody production has been activated and when the number of virus particles in the body is still very small (1,2). Weakened innate immune response in vitamin D deficient individuals allows the virus to multiply before antibody-dependent defenses can raise some protection. Because of the exponential progression of virus multiplication, the effectiveness of supplemental vitamin D is highly time critical and within days becomes increasingly inconsequential. This is important to consider because the referenced Brazilian trial (3) enrolled only symptomatic COVID-19 patients, on average more than ten days after symptom onset. This means that they received the vitamin D supplement about two weeks after the start of the infection. A robust intervention trial of vitamin D supplementation in individuals at an earlier stage of infection, for example with individuals attending testing sites, would be of great value.
The second point is that there is a common misconception about seasonal vitamin D deficiency as a harmless temporary state with no relevant consequences. About half of non-supplemented healthy residents in the UK and other countries at latitudes over 39 degrees have low vitamin D levels during the dark months and not necessarily high prevalence of osteoporosis and risk of bone fracture. What may be relevant for immune cells with rapid turnover does not apply to much more slowly proliferating bone cells. Viral infections of the respiratory tract should be seen as the consequences of vitamin D malnutrition just like deadly childhood infections in children with vitamin A malnutrition. Without the deficiencies the infections are much less likely to take hold and kill.
In countries at high latitude, vitamin D deficiency as defined by current government standards is the most common nutritional deficiency in the winter season. It may be debatable how much supplemental vitamin D should be recommended, 400 IU (10 μg) per day like in the UK, or much more in most other countries at similarly high latitude. The fact is that too few people in the UK get even that much and too few healthcare providers guide their patients to add moderate amounts of vitamin D to their deficient diet (4,5). Analyses of supplement use in the UK and several other countries found a modest but helpful COVID-19 risk reduction with getting some extra vitamin D (6,7).
It is remarkable that we continue to be so blasé about this public health threat that is known to increase the risk of many diseases and pathological conditions. COVID-19 is probably only the latest example of deficiency diseases and we hope that it finally draws attention to this inexcusable state of affairs.
References
1 Calder PC. Nutrition, immunity and COVID-19. BMJ Nutrition, Prevention & Health
2020;3:e000085
2 Zdrenghea, M. T., Makrinioti, H., Bagacean, C., Bush, A., Johnston, S. L., and Stanciu, L. A. Vitamin D modulation of innate immune responses to respiratory viral infections, Rev Med Virol. 2017; 27:e1909. doi: 10.1002/rmv.1909.
3 Murai IH, Fernandes AL, Sales LP, Pinto AJ, Goessler KF, Duran CS, Silva CBR, Franco AS, Macedo MB, Dalmolin HHH, Baggio J, Balbi GGM, Reis BZ, Antonangelo L, Caparbo VF, Gualano B, Prereira RMR. 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 2021 doi:10.1001/jama.2020.26848
4 Lanham-New SA, Webb AR, Cashman KD, et al. Vitamin D and SARS-CoV-2 virus/COVID-19 disease. BMJ Nutrition, Prevention & Health2020;3:e000089
5 Williams J, Williams C. Responsibility for vitamin D supplementation of elderly care home residents in England: falling through the gap between medicine and food. BMJ Nutrition, Prevention & Health2020;3:e000129
6 Ma H, Zhou T, Heianza Y, Qi L. 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 2021:nqaa381. doi: 10.1093/ajcn/nqaa381
7 Louca, P, Murray B, Klaser K, Graham M, Mazidi M, Leeming E, Thompson E, Bowyer R, Drew D, Nguyen L, Merino J, Gomez M, Mompeo O, Costeira R, Sudre C, Gibson R, Steves C, Wolf J, Franks P, Ourselin S, Chan A, Berry S, Valdes A, Calder P, Spector T, Menni C. Dietary supplements during the COVID-19 pandemic: insights from 445,850 users of the COVID Symptom Study app. BMJ Nutrition, Prevention & Health 2021;0. doi:10.1136/bmjnph-2020-000250
Competing interests: No competing interests
Dear Editor
Once again we read a selective approach to evaluating the role of this autocrine signal in the pandemic. The authors do not acknowledge the primacy of physiology in medicine. The physiological serum 25(OH)D3 is between 100 and 150 nmol/L. To acheive this by supplements requires ca 4000 IU pd or more for the obese and some indivduals. This amount is well within the known physiological maximum production rate in the skin exposed to whole-body summer sunlight (10 to 20,000 IU pd).
The authors also ignore evolution. The vitamin D receptor has a 500 million year evolutionary history, its first role being in regulating innate immunty, our first line of defence against microbes, and one which lyses coronavirus rendering them unviable, a trick that vaccines do not replicate. Innate immune defences are pan-specific.
D3 also acts on adaptive immunity to calm the cytokine storm, although this is unlikely to arise if innate defences are fully D3-primed.
Competing interests: No competing interests
Dear Editor:
There are numerous studies that strongly suggest that susceptibilities to COVID-19 severity and complications are driven largely by vitamin D deficiency.
Jain et al found Vitamin D deficiency in 97% of severely ill patients who required ICU admission but in only 33% of asymptomatic cases, suggesting that low levels are a necessary component of severe COVID-19.[1]
De Smet et al found that Vitamin D deficiency on admission was associated with a nearly FOUR-FOLD risk of COVID-19 mortality, and specify that this is independent of age, chronic lung disease, coronary artery disease, hypertension, or diabetes. [2]
Those findings are all the more remarkable considering that vitamin D deficiency is also strongly associated with increased age, chronic lung disease, asthma, coronary artery disease, blood clotting disorders, hypertension, types 1 AND 2 diabetes, obesity, even exposure to tobacco smoke,-- all known as signficant susceptibilities to COVID-19 severity and complications. [3] - [18]
It’s also worth noting that the first two COVID-19 outbreak epicenters were in Wuhan, China and Milan, Italy, both with well-known high levels of air pollution and resulting lung issues in inhabitants. Multiple studies have documented strong correlation between air pollution exposure and vitamin D deficiency. [19] [20] [21]
?
Don’t all of these astonishing parallels indicate that far earlier addressing of vitamin D deficiency is called for than that used in the study protocol for the Sao Paulo, Brazil trial cited by Vimaleswaren, Forouhi, and Khunti??[22] The study protocol used there seems awfully illogical: rather than being given the treatment at diagnosis, it was at a mean of 10.4 days after onset of symptoms that patients were given a single enormous dose of vitamin D — 200,000 IU dissolved in 10 mL of peanut oil (I’m not sure I would keep that down, and I’m not even sick) — rather than lower daily doses, as other studies with successful outcomes did. ??Could such a high single dose have caused hypercalcemia and increased the mortality rate of the test group? And if so, for which individuals/susceptibilties???
It also seems curious that absolute risk reduction rather than relative risk reduction was noted, when vaccine efficacy testing always uses relative risk reduction.??
Further study is always a good call, but given the staggering correlations between vitamin D deficiency and every known susceptibility to COVID-19 severity and complications, doesn’t it do more harm than good to withhold addressing the widespread vitamin D deficiency that is putting citizens of every country at grave risk???
References
1. Jain, A., Chaurasia, R., Sengar, N.S. et al. Analysis of vitamin D level among asymptomatic and critically ill COVID-19 patients and its correlation with inflammatory markers. Sci Rep 10, 20191 (2020). https://doi.org/10.1038/s41598-020-77093-z
2. Dieter De Smet, MD, Kristof De Smet, MD, Pauline Herroelen, MSc, Stefaan Gryspeerdt, MD, Geert A Martens, MD, PhD, Serum 25(OH)D Level on Hospital Admission Associated With COVID-19 Stage and Mortality, American Journal of Clinical Pathology, Volume 155, Issue 3, March 2021, Pages 381–388, https://doi.org/10.1093/ajcp/aqaa252
3. Kweder H, Eidi H. Vitamin D deficiency in elderly: Risk factors and drugs impact on vitamin D status. Avicenna J Med. 2018;8(4): 139-146. Dos:10.4103/ajm.AJM_20_18
4. Boucher B; The Problems of Vitamin D Insufficiency in Older People. Aging Dis. 2012 3(4): 313– 329
5. Martineau A et al; Vitamin D reduces lung disease flare-ups by over 40 percent The Lancet Respiratory Medicine, 2014; DOI: 10.1016/S2213-2600(14)70255-3
6. Gilbert CR, Arum SM, Smith CM. Vitamin D deficiency and chronic lung disease. Can Respir J. 2009; 16(3):75-80. Doi:10.1155/2009/829130
7. Kelly A, Sen C. Is Vitamin D Deficiency the Root of All Pulmonary Evils? Ann Am Thorac Soc. 2014 Feb;11(2):220-2. doi: 10.1513/AnnalsATS.201401-009ED. PMID: 24575988issue 2
8. Martineau??AR, Cates??CJ, Urashima??M, Jensen??M, Griffiths??AP, Nurmatov??U, Sheikh??A, Griffiths??CJ. Vitamin D for the management of asthma. Cochrane Database of Systematic Reviews 2016, Issue 9. Art. No.: CD011511. DOI: 10.1002/14651858.CD011511.pub2. Accessed 06 March 2021.
9. Dhibar DP, Sharma YP, Bhadada SK, Sachdeva N, Sahu KK. Association of Vitamin D Deficiency with Coronary Artery Disease. J. Clin Diagn Res. 2016;10(9):OC24-OC28. Dos:10.7860/JCDR/2016/227188526
10. Khademvatani K, Seyyed-Mohammadzad MH, Akbari M, Rezaei Y, Eskandari R, Rostamzadeeh A; The relationship between vitamin D status and idiopathic lower-extremity deep vein thrombosis Int J Gen Med. 2014;7:303-309. Published 2014 Jun 19. doi:10.2147/IJGM.S64812
11. Mehta V, Agarwal S. Does Vitamin D Deficiency Lead to Hypertension?. Cureus. 2017;9(2):e1038. Published 2017 Feb 17. doi:10.7759/cureus.1038
12. C Michos, ED Do lower vitamin D levels mean higher risk for cardiovascular disease?
https://www.hopkinsmedicine.org/health/wellness-and-prevention/vitamin-d...
13. Vimaleswaran KS, Cavadino A, Berry DJ; LifeLines Cohort Study investigators, et al. Association of vitamin D status with arterial blood pressure and hypertension risk: a mendelian randomisation study. Lancet Diabetes Endocrinol. 2014 Sep;2(9):719-29. doi: 10.1016/S2213-8587(14)70113-5. Epub 2014 Jun 25. PMID: 24974252; PMCID: PMC4582411.
14. Schwalfenberg, G; Vitamin D and diabetes: improvement of glycemic control with vitamin D3 repletion. Can Fam Physician. 2008;54(6):864-866.
15. Jacobo Wortsman, Lois Y Matsuoka, Tai C Chen, Zhiren Lu, Michael F Holick, Decreased bioavailability of vitamin D in obesity, The American Journal of Clinical Nutrition, Volume 72, Issue 3, September 2000, Pages 690–693, https://doi.org/10.1093/ajcn/72.3.690
16. Vimaleswaran KS, Berry DJ, Lu C, et al. Causal relationship between obesity and vitamin D status: bi-directional Mendelian randomization analysis of multiple cohorts. PLoS Med. 2013;10(2):e1001383. doi:10.1371/journal.pmed.1001383
17. Zakharova I, Klimov L, Kuryaninova V, et al. Vitamin D Insufficiency in Overweight and Obese Children and Adolescents. Front Endocrinol (Lausanne). 2019;10:103. Published 2019 Mar 1. doi:10.3389/fendo.2019.00103
18. Nwosu BU, Kum-Nji P. Tobacco smoke exposure is an independent predictor of vitamin D deficiency in US children. PLoS One. 2018 Oct 8;13(10):e0205342. doi: 10.1371/journal.pone.0205342. PMID: 30296288; PMCID: PMC6175516.
19. Agarwal KS, Mughal MZ, Upadhyay P, et al The impact of atmospheric pollution on vitamin D status of infants and toddlers in Delhi, India Archives of Disease in Childhood 2002;87:111-113.
20. Hosseinpanah F, Pour SH, Heibatollahi M, Moghbel N, Asefzade S, Azizi F. The effects of air pollution on vitamin D status in healthy women: a cross sectional study. BMC Public Health. 2010;10:519. Published 2010 Aug 29. doi:10.1186/1471-2458-10-519
21. Hoseinzadeh E, Taha P, Wei C, Godini H, Ashraf GM, Taghavi M, Miri M. The impact of air pollutants, UV exposure and geographic location on vitamin D deficiency. Food Chem Toxicol. 2018 Mar;113:241-254. doi: 10.1016/j.fct.2018.01.052. Epub 2018 Feb 1. PMID: 29409825.
22. Murai IH, Fernandes AL, Sales LP, 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. JAMA2021. doi:10.1001/jama.2020.26848. PMID:33595634
Competing interests: No competing interests
Dear Editor
The failure of the medical profession to promote vitamin D and to fail to correct known widespread deficiency within the population during the pandemic of Covid-19 has been a disgrace. There appears to be a serious and inexcusable ignorance of the function of vitamin D in defensive immunity, and there also appears to be a failure or even a resistance to learn. At risk groups such as the elderly, the obese, those of African or Asian ethnicity, Haredi Jews and others have been dying in excessive numbers and they are all known to have a high incidence of serious vitamin D deficiency. Their deaths could have been minimised by doctors following their medical duty irrespective of the blinkered view of NICE, which regards vitamin D as a pharmaceutical agent rather than for correction of a vitamin/hormone deficiency state, and which avoids the huge evidence base accumulated during the past forty years.
To follow Pascal's wager, what is to be gained by identifying and correcting vitamin D deficiency? A large reduction of deaths. What is to be lost? ￡10 per person per year. What is to be gained by NOT using vitamin D? ￡10 per person per year. What is to be lost? A large number of avoidable deaths.
As a nation we have chosen the option of many avoidable deaths with the saving of a trivial amount of money.
Many individual doctors have been taking and promoting vitamin D. They are to be applauded. But the absence of leadership within the profession has, I repeat, been a disgrace.
Competing interests: No competing interests
Dear Editor,
The Editorial by Vimaleswaran and colleagues [1] rightly calls for further trials of Vitamin D as a therapeutic option in Covid-19, but its recommendations, based primarily upon the NICE review, which only included one small randomised controlled trial of vitamin D as treatment [2], do not go far enough.
They also cite a recent unsupportive Brazilian trial [3], but that study did not administer Vitamin D until a mean of 10 days from onset of symptoms [3]. I wrote to the authors of that study, seeking data to test the hypothesis that the earlier Vitamin D was administered, the shorter the hospital stay, and received the following response: "We agree when you argue that 10 days could be late to verify a significant effect of vitamin D3. Nevertheless, in order to investigate the effect of vitamin D3 in patients with earlier symptoms, the study should be conducted in a primary health care unit, which was not our objective. Furthermore, our sample has a little number of patients with time from symptom onset to enrollment < 5 days, which makes underpowered all the analyses of primary and secondary endpoints."
Hence, in accord with Vimaleswaran and colleagues [1], there are insufficient data to rule in or out a therapeutic role for Vitamin D in Covid-19, but there is a strong physiological rationale for a specific effect [4], and at accepted therapeutic dosing, it really does not cause any harm. Can we afford not to prescribe it?
References
1. Vimaleswaran K S, Forouhi N G, Khunti K. Vitamin D and covid-19 BMJ 2021; 372 :n544 doi:10.1136/bmj.n544
2. NICE. Vitamin D for covid-19: evidence reviews for the use of vitamin D supplementation as prevention and treatment of covid-19. 2020. https://www.nice.org.uk/guidance/ng187/evidence/evidence-reviews-for-the....
3. Murai IH, Fernandes AL, Sales LP, 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 2021. doi:10.1001/jama.2020.26848. pmid:33595634
4. Silberstein M. Correlation between premorbid IL-6 levels and COVID-19 mortality: Potential role for Vitamin D. Int Immunopharmacol. 2020;88:106995. doi:10.1016/j.intimp.2020.106995
Competing interests: No competing interests
In response to John Sharvill
Dear Editor
I'd like to respond to John Sharvill's assertion, "We have seen 5 responses now in relation to the article that continues to advocate the UK dose of Vitamin D, all suggesting that as a nation we are using much too low a dose."
In my previous response, I was not recommending any dosage for anyone in any nation, but rather suggesting that vitamin D deficiency be identified and addressed, BEFORE those suffering from the myriad of health issues associated with both D deficiency and COVID-19 complications are exposed to COVID-19.
To fail to do so invites significant and easily avoidable risk.
Competing interests: No competing interests