Why Vitamin D is so important and not only for COVID, use this as a wake-up call; what is its role in the immune system (in T-cell immunity)?

by Paul Alexander

I have prepared the following piece for you to keep in your library...the key finding surrounds the critical need for vitamin D for proper immune functioning and the dramatic risks if it is low

The guidance by the NIH is however nonsensical, given the overwhelming evidence of effectiveness.

I wanted to give some information on Vitamin D for on my deeper study, I have come to learn extensively how critical Vitamin D is to proper immune functioning (T cell immunity e.g. natural acquired immunity etc.) in COVID and other pathogen.

Vitamin D has important roles in addition to its classic effects on calcium and bone homeostasis. As the vitamin D receptor is expressed on immune cells (B cells, T cells, and antigen-presenting cells), and these immunologic cells are all capable of synthesizing the active vitamin D metabolite, vitamin D has the capability of acting in an autocrine manner in a local immunologic milieu. Vitamin D can modulate the innate and adaptive immune responses. Deficiency in vitamin D is associated with increased autoimmunity and an increased susceptibility to infection”.

For example, T-lymphocytes require a level of minimum 40ng/mL (optimally 50ng/mL) in order to function properly (internal cell signalling). For example, India has a severe insufficiency of vitamin D (97% for adults and elderly had 91% outright deficiency (<20ng/ml).

Evidence indicates that persons with auto-immunity often have a CD8+ T-cell deficiency. CD8+T-cells express the highest amount of the Vitamin D receptors of all immune system cells and can be upregulated with high-dose Vitamin D. A rapid and competent response by CD8+T-cells is a game-changer in COVID-19 outcomes.  “Antibody response is often a poor marker of prior coronavirus infection, particularly in mild infections, and is shorter-lived than virus-reactive T-cells”.

Researchers argue that monitoring and assessing circulating vitamin D levels status and clinical prognostic indices in COVID-19 patients is critical in the responding. “Vitamin D deficiency is associated with compromised inflammatory responses and higher pulmonary involvement in COVID-19 affected patients. Vitamin D assessment, during COVID-19 infection, could be a useful analysis for possible therapeutic interventions”.

Researchers report that in order for T cells to become active members of the body's immune system, “they must transition from so-called "naive" T cells into either killer cells or helper cells (which are charged with "remembering" specific invaders). And, if ample 25-hydroxyvitamin D is not around, the T cells do not make that crucial transition”. “When a T cell is exposed to a foreign pathogen, it extends a signaling device of 'antenna' known as a vitamin D receptor, with which it searches for vitamin D”, Geisler said in a prepared statement. If there is an inadequate vitamin D level, he noted, "they won't even begin to mobilize." “If ample 1,25-hydroxyvitamin D, acting as a paracrine agent (diffused from nearby autocrine / paracrine production in nearby cells) is not around, the T cells do not make that crucial transition” (personal communication, Dr. Whittle).

Persons with auto-immunity need higher doses of Vitamin D to modulate the immune system.  “A 2009 Archives of Internal Medicine study found that 77 percent of U.S. adults and teenagers surveyed did not have the estimated minimum healthful level of 30 nanograms per milliliter in their blood. And just three percent of blacks in the survey were getting enough of the vitamin”.

Vitamin D prevents cytokine storms and “the active metabolite of Vitamin D, alfacalcidol, and cortico-steroids were among the top predicted pharmaceuticals that could normalize SARS-CoV2 induced genes…adjunct therapy with Vitamin D in the context of other immunomodulatory drugs may be a beneficial strategy to dampen hyperinflammation in severe COVID-19”.

At least 50ng/ml 125nmol/L circulating 25-hydroxyvitamin D (25OHD) is required for immune cells to work properly.  This was known in 2008 https://www.grassrootshealth.net/project/our-scientists/ and the Quraishi et al. 2014 infection graph below proves beyond reasonable doubt that this is the case.  50ng/ml circulating 25OHD is needed for fast, complete, innate and adaptive responses to pathogens and to prevent the wildly dysregulated pro-inflammatory responses which cause severe COVID-19, Kawasaki disease, Multisystem Inflammatory Syndrome, sepsis and probably ARDS and severe pneumonia from influenza.


This is a new RCT with inflammatory markers as endpoints rather than clinical covid-19 outcomes.

Only ~44 patients in each arm (treatment & control), so small and will probably be dismissed even if good. The conclusion of their abstract:

"Therapeutic improvement in vitamin D to 80–100 ng/ml has significantly reduced the inflammatory markers associated with COVID-19 without any side effects. Hence, adjunctive Pulse D therapy can be added safely to the existing treatment protocols of COVID-19 for improved outcomes.

A recent ore-print publication by Davies (June 2021) looked at the causal relationship between COVID-19 severity and latitude, and constructed a causal inference framework to validate this hypothesis. Their results verified that that vitamin D status plays a key role in COVID-19 outcomes. Vitamin D prophylaxis potentially offers a widely available, low-risk, highly-scalable, and cost-effective pandemic management strategy including the mitigation of local outbreaks and a second wave. Timely implementation of vitamin D supplementation programs worldwide is critical with initial priority given to those who are at the highest risk, including the elderly, immobile, homebound, BAME and healthcare professionals. Population-wide vitamin D sufficiency could also prevent seasonal respiratory epidemics, decrease our dependence on pharmaceutical solutions, reduce hospitalizations, and thus greatly lower healthcare costs while significantly increasing quality of life”.

A very recent July 2021 report (The EPOCH Times) evidenced the potency of Vitamin D in countering the immune dysregulation that’s common with COVID-19. “As early as November 2020, it was known that there were striking differences in vitamin D status among people who had asymptomatic COVID-19 and those who became severely ill and required intensive care unit (ICU) care. In one study, 32.96 percent of those with asymptomatic cases were vitamin D deficient, compared to 96.82 percent of those who were admitted to the ICU for a severe case.

Kaufman used a retrospective, observational analysis of deidentified 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. “The association between 25(OH)D levels and SARS-CoV-2 positivity was best fitted by the weighted second-order polynomial regression, which indicated strong correlation in the total population (R2 = 0.96) and in analyses stratified by all studied demographic factors. The association between lower SARS-CoV-2 positivity rates and higher circulating 25(OH)D levels remained significant in a multivariable logistic model adjusting for all included demographic factors (adjusted odds ratio 0.984 per ng/mL increment, 95% C.I. 0.983-0.986; p<0.001). SARS-CoV-2 positivity is strongly and inversely associated with circulating 25(OH)D levels, a relationship that persists across latitudes, races/ethnicities, both sexes, and age ranges”. 

COVID-19 patients who were deficient in this inexpensive and widely available vitamin had a higher inflammatory response and a greater fatality rate. The Indian study authors recommended “mass administration of vitamin D supplements to populations at risk for COVID-19,” in a study published in Scientific Reports, but this hasn’t happened, at least not in the United States.

As of April 21, the date the U.S. National Institutes of Health (NIH) last updated its COVID-19 treatment guidelines/vitamin D page, the agency stated, “There are insufficient data to recommend either for or against the use of vitamin D for the prevention or treatment of COVID-19.” The guidance by the NIH is however nonsensical, given the overwhelming evidence of effectiveness.