Vitamin D deficiency has now been shown to increase susceptibility to COVID-19 and increase the risk of COVID-19 severity, including ICU admission and death. Conversely, other published studies have also shown those with higher vitamin D levels (over 30 ng/ml or 75 nmol/L) have a reduced risk of severe symptoms and death due to COVID-19. In fact, an analysis of over 190,000 Americans found that having vitamin D levels of at least 50 ng/ml resulted in a 53% lower positivity rate than those whose levels were less than 20 ng/ml! The first-published randomized controlled trial on vitamin D and COVID-19 found that adding vitamin D to the standard treatment nearly eliminated ICU admissions and did eliminate deaths.
It sounds almost too good to be true... Yet vitamin D is known to influence the expression of thousands of genes and is involved in regulating over 80 biological pathways in the body. Vitamin D is not a miracle drug, nor does it act alone, but it is an important mediator of immune function, and we can largely control whether or not we get enough vitamin D from our daily habits (sun, diet and supplements).
Today we will explain HOW vitamin D acts to protect you from getting COVID-19, and in an upcoming Part 2, we will discuss how vitamin D helps improve symptoms if you do get COVID-19.
Vitamin D is Known to Help Prevent Upper Respiratory Tract Infections
Vitamin D is known to help fight upper respiratory tract infections. As previously discussed, a large meta-analysis including 25 randomized controlled trials with over 11,300 individuals showed that vitamin D supplementation reduced the risk of respiratory tract infections by 70%. GrassrootsHealth participants with vitamin D levels greater than or equal to 40 ng/mL were 41% less likely to have had the flu and 15% less likely to have had a cold in the prior 6 months than participants with levels less than 20 ng/mL.
Acute Respiratory Distress Syndrome (ARDS) is a major complication and cause of death among those with serious COVID-19 infections. When comparing vitamin D levels among those with and at risk of ARDS, one study found that 96% of those at risk of ARDS were deficient in vitamin D.
Vitamin D Can Protect Lung Cells from SARS-CoV-2 Attack
COVID-19 is caused by a coronavirus (a specific type of virus) called SARS-CoV-2. Infection of COVID-19 begins when the SARS-CoV-2 virus enters the cells of the lung by binding the angiotensin-converting enzyme 2 (ACE-2) receptor and de-activating it, resulting in inflammation. Vitamin D is responsible for increasing ACE-2 expression, which allows it to carry out its anti-inflammatory actions to help protect the lungs and keep inflammation at bay.
During the early incubation stage when the virus is hijacking the cell there are generally no symptoms. Most people who are infected with SARS-CoV-2 experience mild-moderate respiratory symptoms and recover without any need for hospitalization or therapy. In those who do experience more severe symptoms, only a small percentage have severe enough symptoms for the virus to be life threatening. This difference in both susceptibility (whether the virus is able to invade) and recovery (how well the body fights it off if it does invade) is attributed to the individual’s immune response. Vitamin D may help protect against COVID-19 specifically through maintenance of physical barriers (susceptibility) and regulation of innate and adaptive immunity (mounting an effective immune response to the virus).
The graphic below provides a very clear illustration of several ways vitamin D acts to directly protect the lungs, from its effect on the protective barrier of the lungs, to its involvement in the maturation of immune cells, and its role in regulating the inflammatory response and inhibiting the cytokine storm (which will be covered in more detail in Part 2).
Vitamin D Regulates the Immune Response
Vitamin D plays a crucial role in regulating immune system activity – both innate and adaptive responses. As previously described, the innate immune system is responsible for the initial defensive front with a central role played by phagocytes. Vitamin D stimulates expansion of these phagocytes (monocytes and macrophages) increasing their ability to fight off the virus by increasing their numbers, as well as increasing their killing capacity through stimulating the production of the anti-viral protein cathelicidin. Vitamin D also acts to regulate the maturation of dendritic cells which are important for activating CD4+ T cells and in turn the rest of the immune response.
Earlier studies have shown that in SARS and influenza the adaptive immune cells, T cells and B cells, are vital in defending the body against the virus. Many studies have found this to be the case in COVID-19 as well, with both antibody and cellular defenses being recruited to the fight. Vitamin D is a potent regulator of adaptive immunity, including both cell-mediated (T cell) and humoral (B cell) immunity.
Once SARS-CoV-2 has been successful at replicating itself and spreading to surrounding cells, mild to moderate symptoms progress (e.g. sore throat, cough, fever and muscle aches) that result from localized and appropriate inflammation, associated tissue damage and antiviral activity of B cells and T cells. CD4+ and CD8+ T cells secrete cytokines (chemical signals that instruct other cells what to do) and are central to the successful elimination of COVID-19, as happens in most people. Unfortunately, more serious symptoms and death can result with an over-reactive or ineffective immune response, as can happen when there is not enough vitamin D for use. The role of vitamin D at this stage will be covered in Part 2.
Thus, vitamin D is important to help fend off an attack by SARS-CoV-2. Ensuring optimal levels of vitamin D is an easy way to help support your immune system response.
Better Results when Taken Together
Nutrients work synergistically in order to carry out specific functions within the body. For example, we have recently discussed how different immune cells rely on a variety of nutrients, including vitamins D, C, B6, B12, zinc, and magnesium, in order to carry out their actions in an immune response. Without these necessary nutrients, immune function may be hindered.
Could a nutrient deficiency be putting a damper on your immune response? Find out by testing your vitamin D, omega-3s, magnesium and other essential elements (including selenium), as well as your inflammation levels, with the new Immune Boost home test kit offered by GrassrootsHealth. Measuring levels is the only way to know if you are supporting your immune system and whether additional changes should be made, with supplementation, dietary changes, or both.
Vitamin D is used by every cell of the body, influences the expression of thousands of genes, and is involved in regulating over 80 biological pathways – importantly, vitamin D is a potent regulator of immune function. However, it may still be surprising how much one vitamin can influence the body’s response to a COVID-19 infection. Vitamin D deficiency has now been shown to increase susceptibility to COVID-19 and increase the risk that if you do have COVID-19, it will be severe enough to require hospitalization in the ICU and lead to death. Conversely, published studies have also shown reduced risk of severe symptoms and death due to COVID-19 with higher vitamin D levels (over 30 ng/mL). In fact, an analysis of over 190,000 Americans found that having a vitamin D level of at least 50 ng/ml resulted in a 53% lower positivity rate for SARS-CoV-2 infection than those with levels less than 20 ng/ml! The first-published randomized controlled trial on vitamin D and COVID-19 found that adding vitamin D to the standard treatment nearly eliminated ICU admissions and did eliminate deaths!
In Part 1 we reviewed how vitamin D acts to protect against COVID-19. Today we will describe how vitamin D influences the immune system in ways that are beneficial, such as preventing the hyper-inflammatory response characteristic of severe COVID-19 infection.
Vitamin D Regulates the Immune Response
Vitamin D plays a crucial role in regulating immune system activity – both innate and adaptive responses. As described in Part 1, vitamin D increases the innate immune response and may help reduce entry of SARS-CoV-2 into cells in the lung and reinforce the physical barriers, or junctions, between cells, which in turn may help prevent the spread of the virus between cells. Vitamin D also stimulates expansion of phagocytes (monocytes and macrophages) increasing their ability to fight off the virus by numbers. In addition, vitamin D directly stimulates phagocytes and lung cells to produce anti-viral proteins, cathelicidin and defensins, that kill the virus. However, an appropriate adaptive immune response is a vital part of the body’s defense against SARS-CoV-2. Vitamin D is a potent regulator of adaptive immunity, including both cell-mediated (T cell) and humoral (B cell) immunity. Vitamin D is needed by these white blood cells to help them recognize, bind to, and destroy SARS-CoV-2.
Click to Enlarge & Print
What Causes A Severe SARS-CoV-2 Infection?
Once SARS-CoV-2 has been successful at replicating itself and spreading to surrounding cells, mild to moderate symptoms progress (e.g. sore throat, cough, fever and muscle aches) as part of a normal immune response to the virus. CD4+ and CD8+ T cell responses including secreted inflammatory cytokines are central to the successful elimination of COVID-19, as happens in most people.
However, in some people the immune response goes awry at this point and generates a hyper-inflammatory state referred to as the “cytokine storm” as depicted in the diagram below. The cytokine storm is the leading theory that explains why some people have a severe reaction to coronaviruses while others only experience mild symptoms. Moderate levels of inflammation are associated with mild-moderate symptoms of COVID-19, whereas the cytokine storm generates a hyper-inflammatory state associated with severe COVID-19 symptoms.
Click to Enlarge & Print
The cytokine storm results from a sudden acute increase in circulating levels of different pro-inflammatory cytokines including IL-6, IL-1, TNF- a, and interferon produced mostly by T cells. These inflammatory cytokines, in addition to the ongoing replication and spread of the virus, trigger more immune cell involvement and tissue damage that leads to acute respiratory distress, multiple organ failure and possibly death. By dampening the cytokine storm, we can reduce the severity of symptoms and the risk of death.
Vitamin D Helps Control the Cytokine Storm and Reduce Symptom Severity
Vitamin D acts in many ways to regulate the adaptive immune response. Vitamin D stimulates CD4+ T cell proliferation and cytokine production, and antibody activity (B cells). Vitamin D acts to regulate T cell response through initiating dendritic cell tolerance. These dendritic cells in turn stimulate the increased production of T regulatory (Treg) cells and their production of anti-inflammatory interleukin (IL)-10, switching the response from being Th1-driven and pro-inflammatory to a Th2-driven anti-inflammatory response.
Vitamin D acts to suppress the production of inflammatory cytokines (such as IL-1, IL-6 and IFN which are predominant in the cytokine storm characteristic of severe COVID-19). Vitamin D also has an effect on the actions of B-cells and inhibits the production of antibodies. Overall, the immunomodulatory actions of vitamin D play a very important role in preventing the activation of an inappropriate hyper-inflammatory immune response.
Because the virus also binds ACE-2 receptors it interrupts the renin-angiotensin system, responsible for regulating blood volume, a pathway that is also regulated by vitamin D. Ensuring sufficient vitamin D may improve response to the virus in the lungs and lessen the impact of SARS-CoV-2 infection on reduced levels of surfactant (a liquid secretion that allows the lungs to open and fill with air) which may then reduce the impact of SARS-CoV-2 infection on the ability to breathe.
Thus, vitamin D is important to help regulate the immune response to a SARS-CoV-2 infection. Ensuring optimal levels of vitamin D is a safe and easy way to help support your immune response.
Do you know your vitamin D level?
Measure your vitamin D level today! When you know what your level is, you can determine next steps to take and how much supplementation may be needed if you are below your target level. A panel of 48 International Vitamin D scientists recommend a level between 40-60 ng/ml (100-150 nmol/L) - where are you?
COVID-19 and Dark Skins
COVID-19 treated by Vitamin D - studies, reports, videos
As of April 7 the page had: 34 trials, 5 trial results, 16 meta-analyses and reviews, 52 observations, 34 recommendations, 54 associations, 86 speculations, 43 videos see related: Governments, HealthProblems, Hospitals, Dark Skins, 26 risk factors are ALL associated with low Vit D, Recent Virus pages Fight COVID-19 with 50K Vit D weekly
and has the following recent updates
- Less COVID-19 infection, mortality in countries with higher Vitamin D (Asia in this case) – May 2021
- COVID-19 was the third-leading cause of death in the US, especially in those with dark skins - April 1, 2021
- Children with COVID-19 and low levels of Vitamin D have more severe cases – March 31, 2021
- Risk of COVID-19 death was 4.9 X higher if very low vitamin D – March 31, 2021 17th mortality observation
- Diabetes has many bidirectional links with COVID-19 – March 2021
- Diabetes is one of the 26 health risks identified by the CDC for getting COVID-19 - ALL of which are associated with low vitamin D
- COVID-19 was 2.6X more severe if very low Vitamin D (43 studies) – meta-analysis March 26, 2021
- To protect against COVID-19, how much vitamin D – 20 to 50 ng – March 19, 2021
- COVID-19 mortality for Parkinson’s is 1 in 5, speculates that vitamin D could help - March 18, 2021
- Prefer 40 – 60 ng of Vitamin D to minimize COVID-19 – March 17, 2021
- The lower the Vitamin D, the worse the COVID-19 (600 in Turkey)– March 2021
- COVID-19 prognostic indicators in plasma extrapolate to zero if Vitamin D is 40 to 80 ng – March 2021
- COVID public health messages 1, 2, and 3 should be - vitamin d vitamin d, vitamin d (video and transcript) - Mar 5, 2021
- COVID-19 mortality 2X higher if low Vitamin D (Mexican hospital, preprint) - March 2021
- Chronic Fatigue Syndrome and long-haul COVID-19
- low vitamin D, autoimmune and cytokine storms may be involved on both
- 2.1 X more COVID-19 deaths in European countries with less than 20 ng of vitamin D – March 12, 2021
- Supporting non-standard but proven ways to fight COVID-19 can result in job loss – March 2021
- 3X less likely to die of COVID-19 if good level of vitamin D (seniors in Boston)– March 8, 2021
- Low Vitamin D associated with 2.7X more severe COVID-19 – 12th MA March 5, 2021
- COVID-19 fought by Vitamin D or Heat - Drs Seheult and Patrick video - March 3, 2021
- Vitamin D Deficiency and Covid-19: Book by Drs Anderson and Grimes - July 2020
- Vitamin D recommendations for COVID-19 – Spanish Geriatrics Society – March 2021
- 250,000 FREE bottles of vitamin D to fight COVID-19 by Dr. Murray at iHerb – March 3 2021 Dr. Oz show
- Vitamin D and COVID-19 webinar - Feb 24, 2021
- Mongolia's National Vitamin D3 Program started in 2019
- COVID-19 what it is, prevention by Functional Nutrition doctor - Feb 2021
- Vitamin D reduced COVID-19 inflammation (60,000 IU daily for 8 days) - RCT Feb 2021
- All COVID-19 in ICU had low vitamin D, no difference in outcome if low vs very low – Feb 2021
- Low-cost Ivermectin and Vitamin D fight COVID-19 – Marik video 1 hr – Feb 18, 2021
- Low vitamin D associated with COVID-19 problems in NYC hospitals – Feb 2021
- All COVID-19 patients had low vitamin D, the lowest were more likely to die – Feb 18, 2021
- 200,000 IU of Vitamin D can not catch up when COVID-19 has a 10 day head start – RCT Feb 17, 2021
- 5X less likely to enter ICU with COVID-19 if get Calcifediol (semi-activated vitamin D) - RCT Feb 19, 2021
- Ultra-Orthodox Jews have high levels of COVID-19 (and ultra low Vitamin D ) - Feb 2021
- c19study.com/d Summary of Vitamin D and COVID studies (the following is updated automatically)
- Vitamin D can prevent severe COVID-19 in Latin America too – review Feb 1, 2021
- Vitamin D and COVID-19: 1 hour simple video - Jan 31, 2021
- Higher vitamin D in a country is associated with fewer COVID-19 cases (in Asia) Feb 3, 2021 44th association
- Vitamin-D and COVID-19: time for the profession to take a stand – Jan 20, 2021
- Roll Call of Credible Experts Advocating Vitamin D for COVID-19 - Jan 26, 2021
- Call for immediate action - Fight COVID-19 with vitamin D (up to 4,000 IU) - Jan 28, 2021
- Vitamin D, Zinc, etc. look promising for COVID-19 (Holick) – Jan 25, 2021
- Heavy Smokers 2.2 X more likely to be hospitalized with COVID-19 (they typically have 10 ng less Vitamin D) Jan 25 FREE PDF
- Vitamin D plus Inositol might help pregnancies during COVID-19 – April 2021
- MATH plus protocol for COVID-19 includes Calcifediol or Vitamin D - Jan 2021
- Vitamin D supplementation fights COVID-19 – 11th meta-analysis Jan 24, 2021
- Vitamin D helps the immune system fight COVID-19 – video Jan 21, 2021
- COVID-19 2.7 X more likely to be severe if less than 8 ng of vitamin D (China) – Jan 2021
- 2.7 fewer COVID-19 hospital deaths in those having more than 30 ng of vitamin D – Mayo Jan 9, 2021
- Vitamin D Help Us Fight Infections - interview of Dr. Thakkar (transcript) Jan 20, 2021
- COVID-19 onset strongly associated with latitude in Europe (Vitamin D)– Jan 21, 2021
- France: 73 experts and 6 academies recommend vitamin D to prevent COVID-19 Jan 19, 2021
- Worse COVID-19 patients got 400,000 IU of vitamin D, deaths cut in half – Jan 14, 2021
- Vitamin D-COVID interview by Dr. Campbell of Davies (member of UK Parliament) - Jan 17, 2021
- Iranians with COVID-19 were 2.3 X more likely to die if low vitamin D – Jan 2021
- Many COVID-19 risks are associated with low vitamin D (7 studies) – Systematic Review Jan 2021
- 40 ng of Vitamin D to fight COVID 15K to 50K weekly or 100K monthly - Spanish Jan 2021
- Poor COVID-19 prognosis was 6 X more likely if low vitamin D – Jan 21, 2021
- Unraveling the roles of vitamin D status and melanin during COVID-19 (Review) Jan 11
- 30 x fewer COVID-19 deaths in those getting 400,000 IU of Vitamin D - Jan 2021
- 2.8 X fewer COVID-19 nursing home deaths if add 10,000 IU Vitamin D daily for a week (small observation)- Jan 2021
- 3.7 X less likely to die of COVID-19 if supplemented with Vitamin D - meta-analysis Jan 5, 2021
- COVID-19 test positive 4.5 X more likely if had low vitamin D test within 4 years – Jan 6, 2021
- Don’t Let COVID-19 Patients Die With Vitamin D Deficiency - Jan 5, 2021
- Less likely to test positive for COVID-19 if higher Vitamin D – meta-analysis Jan 6, 2021
- Vitamin D reduces COVID-19 by 80 percent - anonymous meta-analysis - Jan 5, 2021
- COVID 19 Video - Drs. Seheult and Campbell : Lessons Learned and a Look Ahead - Jan 4
- Many drugs increase ACE2 and COVID-19 (176 page review) - Dec 2020
- Italian nursing home COVID-19 – 4X less likely to die if taking Vitamin D– Dec 22, 2020
- Take 50,000 IU of Vitamin D weekly before and after COVID-19 vaccination by VItaminDWiki
- COVID-19 lung infection upsets Vitamin D genes (so more or different form of Vit D is required) - Dec 22, 2020
- COVID-19 Disease and Vitamin D: A Mini-Review – Dec 15, 2020
- French Consensus – 200,000 IU of Vitamin D if get COVID-19 – Dec 22, 2020
- Rational approach to COVID-19: 50k-100k of Vitamin D weekly – Dec 2020
- Shift workers 2X more likely to get COVID-19 (low Vitamin D) - Dec 2020
- COVID-19 plus pneumonia in ICU with low vitamin D equaled Death - Dec 2020
- Excellent on-going analysis of Vitamin D and COVID-19 publications
- Those getting intermittent vitamin D were 7 X less likely to die of COVID-19 - Dec 11, 2020
- COVID-19 patients with low vitamin D had far fewer natural killer cells – Dec 2020
- COVID-19 Vitamin D: Overview of Evidence by Dr. Seheult (Video and transcript) - Dec 10, 2020
- 75 articles indicate that Vitamin D should fight COVID-19 – Evidence Review Dec 10, 2020
- COVID-19 Vitamin D: Overview by Dr. in Sri Lanka (Video and transcript) - Dec 8, 2020
- Vitamin D recommended to fight COVID-19 by 2 groups – Dec 7, 2020
- Vitamin D helps athletes while reducing their COVID-19 risk - Dec 4, 2020
- 5X more likely to test positive for COVID-19 if low vitamin D in previous 5 years (900,000 people) - Dec 4, 2020
- 5.8 X more likely to die of COVID-19 if low vitamin D - Systematic Review Dec 3, 2020
- Evidence of Vitamin D fighting COVID-19 etc. - take 4,000 IU if less than 20 ng (UK) – Dec 1, 2020
- 3.8 X higher risk of COVID-19 death if low vitamin D – Belgium Nov 25, 2020
- Hyperglycemic 2X more likely to have severe COVID-19 - Nov 2020 Diabetes
- A Medical School COVID-19 protocol includes Vitamin D for all phases – Marik Nov 2020
- Fight COVID-19 without drugs or vaccines, Vitamin D is the single most-studied way – Nov 2020
- Hospital COVID-19 observation: 7X more likely to live if more than 20 ng of vitamin D– Nov 19, 2020
- Higher vitamin D associated with fewer cases and deaths in India Nov 2020
- COVID-19 defeated 3x faster by 420,000 IU Vitamin D nanoemulsion – RCT Nov 12, 2020
- 9X COVID-19 survival in nursing home if had 80,000 IU dose of vitamin D in previous month – Oct 2020
- Rate of COVID-19 test positive is 40 pcnt lower if high vitamin D (192,000 people) - Holick Sept 2020