Vitamin D and COVID-19
We are in the dark days of a novel pandemic where any glimmer of preventive hope on the horizon is appreciated in this battle. Research has recently sounded the horns of prevention in terms of taking vitamin D to fortify the body’s immune system against influenza and the novel coronavirus. According to the most recent public health outcry, the most at-risk population should be fortifying themselves with 10,000 IU of vitamin D daily in the weeks before winter and then stabilize intake at 5,000 IU per day to maintain blood levels of 40–50 ng/ml, although, admittedly, this research is controversial and needs more study.
What Role Does Vitamin D Play in Reducing COVID 19 Risk?
Vitamin D acts by three mechanisms — maintaining a physical barrier, increasing natural cellular immunity, and increasing adaptive immunity. Vitamin D helps keep tight gap junctions between cells. Several articles have suggested how viruses disturb junction integrity, increasing infection by the viruses and other microorganisms that can squeeze through the leaky membranes. This is a physical barrier function.
Innate immunity is enhanced through the induction of antimicrobial peptides, which exhibit direct antiviral and antimicrobial activities against a spectrum of microbes, including enveloped and nonenveloped viruses, fungi, and bacteria. These peptides kill the invading pathogens by invading their cell membrane and neutralizing necessary biological activities.
Cellular immunity is enhanced in part by reducing the cytokine storm induced by the innate immune system. The innate immune system generates both pro-inflammatory and anti-inflammatory cytokines in response to viral infections. Vitamin D can reduce the production of pro-inflammatory cytokines while increasing the expression of anti-inflammatory cytokines.
Vitamin D supplementation also enhances the expression of genes related to antioxidation. Increased glutathione productions spare the use of vitamin C, which has antimicrobial and antioxidant capabilities. Glutathione is a peptide involved as an antioxidant, and vitamin D affects its expression.
What is the Optimal Blood Level for Vitamin D in the Prevention of COVID-19?
Research shows that 38 ng/L was sufficient for reducing community-acquired pneumonia, although the degree of protection increased as blood level increased with the optimal range being 40–60 ng/ml.
High doses of vitamin D seem to be well tolerated with doses of 60,000IU/d found in the literature to treat asthma, rheumatoid arthritis, rickets, and tuberculosis in the 1930s and 40s. High doses of vitamin D over prolonged periods can damage the kidneys; however, we are talking about high doses for a short time. The tolerable upper limit for vitamin D is 4,000 IU/day. Research shows that doses of 25,000 IU have not caused severe side-effects. Everyone is different, and we err on the side of caution.
Obviously, the research on COVID is challenging the tolerable upper limit in its recommendations suggesting that supplementation could improve the outcome of the clinical COVID 19 condition.
Improvement of Clinical Outcomes of COVID-19 with Supplementation
Recent research results have shown that having a favorable clinical outcome rather than a critical outcome was increased approximately 19.61 times with a high vitamin D level. Vitamin D status was found to be significantly associated with clinical outcomes. Of 212 cases of COVID 19, 23.1 % were identified as mild, 27.8 % were ordinary, and 26.4 % were severe, and 22. % were critical. Mean serum vitamin D level was 23.8 ng/ml with < 20 being defined as deficient. Using multinomial logistic regression, a distinct relationship was found between the level of vitamin D and the severity of clinical outcomes between all levels of severity compared to levels of vitamin D.
As for the link with immune function, one systematic review and one met-analysis of data from 11,321 people published in the British Medical Journal found that people who took weekly or daily supplements of vitamin D were less likely to develop respiratory tract infections than those who didn’t. There is a conflicting review in the same journal that said there was no relationship. Then, another review published in the same journal issue stated that according to the Royal Society there is a biologically plausible reason to suspect vitamin D deficiency to be involved in immune dysregulation. Clearly we see confusion in study results. In the midst of all this mud, Dr. Fauci himself states he takes two vitamins to ward off COVID, vitamin D, and vitamin C.
Public Health Call to Action
Research is showing that vitamin D deficiency is common and may contribute to increased risk of respiratory infection, particularly COVID-19. It is advised by some groups that the following be urgently supplemented with 800–2,000 IU of vitamin D to enhance their resistance to COVID-19:
· All older adults
· Hospital inpatients
· Nursing home residents
· Those with darker skins
· Vegetarians
· Those who are overweight or obese
· Smokers
· Healthcare workers
Conclusion
While there is a slight discrepancy between the amounts of vitamin D being recommended, the fact that supplementation is being recommended should not be taken lightly. Every nursing home resident should have it in their care plan to increase vitamin D intake to 1,000–10,000 IU per day, depending on their blood levels. Deficient individuals may need to supplement with 10,000 IU 5 days per week for six weeks and then drop down to 5,000 IU per day until optimal blood levels are reached, and then maintenance may be set at 2,000 IU/d. Others who have higher blood levels of vitamin D may only need 800 IU per day.
The best thing to do is get your blood level for vitamin D measured and then consult with your health care provider for repletion and maintenance dosing recommendations.
