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 the 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.
What Role Does Vitamin D Play in Reducing COVID 19 Risk
Vitamin D acts by 3 mechanisms – maintaining a physical barrier, increasing cellular natural immunity, and increasing adaptive immunity. For example, Vitamin D helps maintain tight gap junctions between cells. Several articles have suggested how viruses disturb junction integrity, increasing infection by the viruses and other microorganisms who 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 non-enveloped 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 expressing of anti-inflammatory cytokines.
Vitamin D supplementation also enhances the expression of genes related to antioxidation relative to increased glutathione production. Increased glutathione production spares the use of vitamin C which has antimicrobial and antioxidant capabilities. Glutathione is a peptide molecule that functions as an antioxidant.
What is the Optimal Blood Level for Vitamin D in Prevention of COVID-19? Research shows that 38 ng/ml was sufficient for reducing community acquired pneumonia although the degree of protection rose 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 60,000 IU/d found in the literature to treat asthma, rheumatoid arthritis, rickets, and tuberculosis in the 1930’s and 40’s. High doses of vitamin D over prolonged periods can damage the kidneys, however, there is no evidence that 20-50 mcg/day cause any harm (800-2000 IU). The tolerable upper limit for vitamin D is 4,000 IU/day.
Obviously, the research on COVID is challenging the tolerable upper limit in its recommendations suggesting that supplementation in the given range could improve outcome of the clinical COVID 19 condition. We have to remember that this is for short periods of time, however, such as the time period before winter and in persons who have low vitamin D and need repletion as well as high risk persons. The rate of deficiency in the US is about 41% for Caucasians and 82.1% for black Americans.
Improvement of Clinical Outcomes of COVID-19 with Supplementation.
Recent research results have shown that having a mild clinical outcome rather than a critical outcome were 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 about 22.5% were critical. Mean serum vitamin D level was 23.8 ng/ml with < 20 being classified as deficient. Using multinomial logistic regression, a distinct relationship was found between the level of vitamin D and the severity of clinical outcomes for each clinical risk category vs. vitamin D level.
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 many public health groups that all older adults, hospital inpatients, nursing home residents and other vulnerable groups such as those with darker skins and vegetarians , those who are overweight or obese, smokers and healthcare workers be urgently supplemented with 800-2000 IU of vitamin D to enhance their resistance to COVID 19 and that this advice be quickly extended to the general adult population.
It might be noted that evidence is contradictory. Studies put out by NICE suggest that evidence is inconclusive for a role for vitamin D in the prevention of respiratory infections. However, recent evidence also points to the contrary. Clearly more evidence-based trials are needed before a formal public health call to action can be appreciated in a research sense.
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 2,000-10,000 IU per day depending on their blood levels. Deficient individuals may need to supplement with 10,000 IU 5 days per week for 6 weeks and then drop down to 5,000 IU per day until blood levels reach 50-60 ng/ml and then continue with 800- 2,000 IU/day. 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. Nevertheless, no individual should be left with a vitamin D deficiency during this pandemic.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
#COVID-19 #vitaminD #coronavirus #vitamins #vitamin D deficiency