There is more and more evidence suggesting that vitamin D might help protect against becoming infected with, and developing serious symptoms, of COVID-19. We know, for example, that people with low vitamin D levels may be more susceptible to upper respiratory tract infections. In one study, an analysis of raw data from roughly 11,000 participants in 25 clinical trials conducted in 14 countries showed that optimizing VIT D levels did help reduce the risk of acute respiratory syndromes.1
Another study found a correlation between the amount of circulating vitamin D and COVID risk. This study used a retrospective, observational analysis of de-identified tests performed at a national clinical laboratory to determine if circulating 25-hydroxyvitamin D (25(OH)D) levels are associated with severe acute respiratory disease coronavirus 2 (SARS-CoV-2) positivity rates. Over 190,000 patients from all 50 states with SARS-CoV-2 results performed mid-March through mid-June, 2020 and matching 25(OH)D results from the preceding 12 months were included. Researchers noted “Our findings provide further rationale to explore the role of vitamin D supplementation in reducing the risk for SARS-CoV-2 infection and COVID-19 disease. If controlled trials find this relationship to be causative, the implications are vast and would present a cheap, readily-available method for helping prevent infection, especially for those with vitamin D deficiency.”2
And still more news.
Results from a randomized controlled trial that were published this month (October 2020) showed that vitamin D levels correlated to whether patients infected with COVID required treatment in an intensive care unit (ICU): those with higher levels of circulating vitamin D had less likelihood of ICU admission. Although the number of deaths was todo small to say for sure, vitamin D may actually abolish the risk of death from COVID-19. The study looked at 76 patients with COVID pneumonia in Spain. They were administered the equivalent to 106,400 IU vitamin D on day 1, 53,200 IU on days 3 and 7, and 53,200 IU weekly thereafter. If this were given as daily doses, it would be the equivalent of 30,400 per day for the first week, followed by a maintenance dose of 7,600 IU per day.3
The vitamin D status of the patients was not measured. However, the average vitamin D status in this region of Spain during the time of year in which the study was conducted is 16 ng/mL. A single dose of 100,000 IU vitamin D tends to raise a 25(OH)D of 10 ng/mL into the 20-30 ng/mL range. It’s likely that the bolus dosing (a single dose of a drug or other substance given over a short period of time, usually given by infusion or injection) in the first week brought the patients' vitamin D status into the 30-40 ng/mL range by the end of the week, and that most of the healing took place in the circa 40 ng/mL range. The results showed that 50% of the control group (13 people) required admission to the ICU, but only 2% of those in the vitamin D group (one person) required admission to the ICU.
Expressed as relative risk, vitamin D reduced the risk of ICU admission 25-fold and appeared to eliminate 96% of the risk of ICU admission. Researchers concluded “Our pilot study demonstrated that administration of a high dose of Calcifediol or 25-hydroxyvitamin D, a main metabolite of vitamin D endocrine system, significantly reduced the need for ICU treatment of patients requiring hospitalization due to proven COVID-19. Calcifediol seems to be able to reduce severity of the disease, but larger trials with groups properly matched will be required to show a definitive answer.”
Beyond COVID…the comprehensive benefits of vitamin D.
We have known for a very long time that vitamin D is critically needed for bone health throughout life. Women who are vitamin D deficient can lose as much as 3% to 4% of their skeletal mass per year. More recently we have learned that vitamin D deficiency can contribute to neurodegenerative disease and dementia while a recent study found that being overweight and having low blood levels of vitamin D may increase the risk in children of developing pediatric-onset multiple sclerosis.4 There also is accumulating data to suggest that vitamin D deficiency may play an important role in multiple conditions including cardiovascular disease (CVD) and colon cancer while additionally provoking symptoms like fatigue, depression, and joint pain. Conversely, studies have noted that women who had the highest intake of vitamin D reduced their risk of developing multiple sclerosis by 41% and rheumatoid arthritis by 44%.5
Vitamin D is also recognized as an integral component in our immune defense system. The manner in which it works is by causing the induction of antimicrobial peptides in response to both viral and bacterial stimuli, suggesting a potential mechanism by which vitamin D inducible protection against respiratory pathogens might be mediated. Vitamin D metabolites have also been reported to induce other innate antimicrobial effector mechanisms, including induction of autophagy and synthesis of reactive nitrogen intermediates and reactive oxygen intermediates.6 But what this science really tells us is that vitamin D can help our immunity!
Get your D on.
As important as vitamin D is to so many aspects of our health and brain’s wellbeing, deficiency is extremely common. In my autoimmune neurology practice, almost every patient at an initial visit has unacceptable levels in their serum vitamin D. Insufficiency as a whole is highest among people who are elderly, those who have cancer, autoimmune disease, are indoors more the outdoors, institutionalized, or hospitalized. In the United States, 60% of nursing home residents and 57% of hospitalized patients were found to be vitamin D deficient. However, vitamin D insufficiency is not restricted to the elderly and hospitalized population; several studies have found a high prevalence of vitamin D deficiency among healthy, young adults and children.7
I generally recommend that patients have a vitamin D level in the therapeutic range of 60-90ng/ml. Remember, the upper limit of “normal” on lab values is 30ng/ ml, but that is WAY too low. Everyone should be on vitamin D supplementation for general health and especially relevant to neurodegenerative disease as we’ve discussed in our previous blog:
While it’s not easy to get the vitamin D we all need from being outdoors (more to come about this[FG1] in another update in our vitamin D series) spend time with “Mother Nature” and basking in the beauty that surrounds you are still valid recommendations for your wellness plan!
Dr. Suzanne Gazda
1 University of Queen Mary London. (2017, February 16). Vitamin D protects against colds and flu, finds major global study. ScienceDaily. Retrieved October 25, 2020 from www.sciencedaily.com/releases/2017/02/170216110002.htm
2 Harvey W., Kaufman, Justin K. Niles, Martin H. Kroll, Caixia Bi, Michael F. Holick. SARS-CoV-2 positivity rates associated with circulating 25-hydroxyvitamin D levels. (September 17, 2020)
3 Marta Entrenas Castillo, Luis Manuel Entrenas Costa, José Manuel Vaquero Barrios, Juan Francisco Alcalá Díaz, José López Miranda, Roger Bouillon, José Manuel Quesada Gomez.
“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.” The Journal of Steroid Biochemistry and Molecular Biology.
Volume 203, 2020, 105751, ISSN 0960-0760,
4 National Multiple Sclerosis Society
5 Holick M. F. (2011). Vitamin D: a d-lightful solution for health. Journal of investigative medicine: the official publication of the American Federation for Clinical Research, 59(6), 872–880. https://doi.org/10.2310/JIM.0b013e318214ea2d
6 Martineau AR, Jolliffe DA, Greenberg L, et al. Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis. Southampton (UK): NIHR Journals Library; 2019 Jan. (Health Technology Assessment, No. 23.2.) Scientific summary. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536316/
7 Tangpricha, V. MD, PhD. What is the prevalence of vitamin D deficiency in the US? Medscape. (2020) https://www.medscape.com/answers/128762-54281/what-is-the-prevalence-of-vitamin-d-deficiency-in-the-us
Blog Part 2.