Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy

Abstract:

Nearly four years after its first appearance, and having gone from pandemic to endemic, the SARS-CoV-2 remains out of control globally. The purpose of this study was to evaluate the clinical efficacy of vitamin D (VD) in COVID-19 and long COVID-19, explain the discrepancy in clinical outcomes and highlight the potential impact of metformin on VD efficacy in recent articles.

Articles from January 2022 to August 2023 were selected for this review. The objective of this study was achieved by reviewing, analyzing, and discussing articles demonstrating (1) the mechanism of action of VD (2) observational or randomized clinical trials (RCTs) that support or not the beneficial clinical effects of VD in COVID-19 or long COVID. (3) genetic and non-genetic reasons for the variation in the effects of VD.

Articles were collected from electronic databases such as PubMed, Scopus, MEDLINE, Google Scholar, Egyptian Knowledge Bank, Science Direct, and Cochrane Database of Systematic Reviews. Twenty three studies conducted in vitro or in animal models indicated that VD may act in COVID-19 through protecting the respiratory system by antimicrobial peptide cathelicidins, reducing lung inflammation, regulating innate and adaptive immune functions and up regulation of autophagy gene activity. Our review identified 58 clinical studies that met the criteria. The number of publications supporting a beneficial clinical activity of VD in treating COVID-19 was 49 (86%), including 12 meta-analyses. Although the total patients included in all articles was 14,071,273, patients included in publications supporting a beneficial role of VD in COVID-19 were 14,029,411 (99.7%).

Collectively, extensive observational studies indicated a decisive relationship between low VD levels and the severity of COVID-19 and mortality outcomes. Importantly, evidence from intervention studies has demonstrated the effectiveness of VD supplements in treating COVID-19. Furthermore, the results of 4 observational studies supported the beneficial role of VD in alleviating symptoms of long COVID-19 disease. However, eight RCTs and one meta-analysis of RCTs may contain low-grade evidence against a beneficial role of VD in COVID-19. Twenty-five articles have addressed the association between VDR and DBP genetic polymorphisms and treatment failure of VD in COVID-19.

Impaired VDR signaling may underlie the variability of VD effects as non-genetic mechanisms. Interestingly, in recent studies, metformin has a beneficial therapeutic role in COVID-19 and long COVID-19, possibly by improving AMPK signaling of the VDR and enhancing the efficacy of the VD. In conclusion, evidence has been significantly strengthened over the past 18 months, with several meta-analyses and RCTs reporting conclusive beneficial effects of VD supplementation against COVID-19 and highlighting metformin to improve VDR sensitivity and efficacy in treating COVID-19 and long COVID-19.

Source: Gomaa, A.A., Abdel-Wadood, Y.A., Thabet, R.H. et al. Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy. Inflammopharmacol (2023). https://doi.org/10.1007/s10787-023-01383-x https://link.springer.com/article/10.1007/s10787-023-01383-x (Full text)

Neuroimmunological Effect of Vitamin D on Neuropsychiatric Long COVID Syndrome: A Review

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19). COVID-19 is now recognized as a multiorgan disease with a broad spectrum of manifestations. A substantial proportion of individuals who have recovered from COVID-19 are experiencing persistent, prolonged, and often incapacitating sequelae, collectively referred to as long COVID. To date, definitive diagnostic criteria for long COVID diagnosis remain elusive.
An emerging public health threat is neuropsychiatric long COVID, encompassing a broad range of manifestations, such as sleep disturbance, anxiety, depression, brain fog, and fatigue. Although the precise mechanisms underlying the neuropsychiatric complications of long COVID are presently not fully elucidated, neural cytolytic effects, neuroinflammation, cerebral microvascular compromise, breakdown of the blood–brain barrier (BBB), thrombosis, hypoxia, neurotransmitter dysregulation, and provoked neurodegeneration are pathophysiologically linked to long-term neuropsychiatric consequences, in addition to systemic hyperinflammation and maladaptation of the renin–angiotensin–aldosterone system.
Vitamin D, a fat-soluble secosteroid, is a potent immunomodulatory hormone with potential beneficial effects on anti-inflammatory responses, neuroprotection, monoamine neurotransmission, BBB integrity, vasculometabolic functions, gut microbiota, and telomere stability in different phases of SARS-CoV-2 infection, acting through both genomic and nongenomic pathways.
Here, we provide an up-to-date review of the potential mechanisms and pathophysiology of neuropsychiatric long COVID syndrome and the plausible neurological contributions of vitamin D in mitigating the effects of long COVID.
Source: Chen T-B, Chang C-M, Yang C-C, Tsai I-J, Wei C-Y, Yang H-W, Yang C-P. Neuroimmunological Effect of Vitamin D on Neuropsychiatric Long COVID Syndrome: A Review. Nutrients. 2023; 15(17):3802. https://doi.org/10.3390/nu15173802 https://www.mdpi.com/2072-6643/15/17/3802 (Full text)

Role of Vitamin D Supplementation for Symptoms and Lung Function Improvement in Long COVID Patient

Abstract:

Post-Acute COVID-19 Syndrome (PACS) or acute post-COVID-19 syndrome or also known as “Long Covid”, is a collection of persistent symptoms and long-term complications more than four weeks after the onset of initial symptoms. One of the leading causes of these long-term complications is pulmonary fibrosis, with an incidence of almost 25% in patients a year after hospitalization. Vitamin D is an important substance to our body homeostasis and regulation. Vitamin D has pleiotropic effect as pulmonary antifibrosis. This research aims to directly provide vitamin D3 supplements, especially in improving lung function in pulmonary fibrosis patients after COVID-19 infection.

This study was a one-group, quasiexperimental pretest-posttest design conducted at Labuang Baji hospitals in the eastern part of Indonesia. The population of this study was patients post-covid-19 infection with negative PCR results at least three months, had persistent symptoms of covid 19, and a CT scan confirmed pulmonary fibrosis or destroyed lung results. Lung function was measured using spirometry before and after the intervention (Vitamin D3 5000 IU supplementation with a frequency of once per day for two months). This study included 20 cases of Lung Fibrosis post-Covid-19. The majority of respondents were women and between the ages of 40 and 49. Among 20 patients, most of them fatigue or dyspneu or shortness of breath as their main symptoms.

After 2-months supplementation of Vitamin D 5000 IU, number of patients who had shortness of breath and fatigue reduced significantly (From 11 to 3 and from 11 to 2 patients, respectively). 85% of our patient had deficient-insufficient status of vitamin D. We found restrictive pattern as a dominant lung function in our patient. There was significant improvement in lung function status after 2-months vitamin D supplementation (p=0.02). Vitamin D supplementation for Long COVID may have benefit for symptoms and lung function improvement.

Source: Irawaty Djaharuddin, Muzakkir Amir, Jamaluddin Madolangan, Ahmad Fachry Toaha, Muthiah Nur Afifah, Muhammad Zaki Rahmani, Izza fauziah Irfan.Role of Vitamin D Supplementation for Symptoms and Lung Function Improvement in Long COVID Patient. Teikyo Medical Journal. Volume 45, Issue 09, November, 2022 https://www.teikyomedicaljournal.com/volume/TMJ/45/10/role-of-vitamin-d-supplementation-for-symptoms-and-lung-function-improvement-in-long-covid-patient-638db40f96abb.pdf (Full text)

A Narrative Review on the Potential Role of Vitamin D3 in the Prevention, Protection, and Disease Mitigation of Acute and Long COVID-19

Abstract:

Purpose of Review: The coronavirus disease 2019 (COVID-19) pandemic has challenged global health systems and economies from January 2020. COVID-19 caused by the infectious severe acute respiratory syndrome coronavirus (SARS-CoV-2) has acute respiratory and cardiometabolic symptoms that can be severe and lethal. Long-term physiological and psychological symptoms, known as long COVID-19, persist affecting multiple organ systems. While vaccinations support the fight against SARS-CoV-2, other effective mechanisms of population protection should exist given the presence of yet unvaccinated and at-risk vulnerable groups, global disease comorbidities, and short-lived vaccine responses. The review proposes vitamin D3 as a plausible molecule for prevention, protection, and disease mitigation of acute and long COVID-19.

Recent Findings: Epidemiological studies have shown that individuals who were deficient in vitamin D3 had worse COVID-19 health outcomes and mortality rates. Higher doses of vitamin D3 supplementation may improve health and survivorship in individuals of various age groups, comorbidities, and severity of disease symptoms.

Summary: Vitamin D3’s biological effects can provide protection and repair in multiple organ systems affected by SARS-CoV-2. Vitamin D3 supplementation can potentially support disease-mitigation in acute and long COVID-19.

Source: Moukayed, M. A Narrative Review on the Potential Role of Vitamin D3 in the Prevention, Protection, and Disease Mitigation of Acute and Long COVID-19. Curr Nutr Rep (2023). https://doi.org/10.1007/s13668-023-00471-2 https://link.springer.com/article/10.1007/s13668-023-00471-2 (Full text)

Low vitamin D levels are associated with Long COVID syndrome in COVID-19 survivors

Abstract:

Purpose: Long-COVID is an emerging syndrome affecting 50-70% of COVID-19 survivors which still lacks predicting factors. Due to the extra-skeletal effects of vitamin D, we retrospectively assessed in COVID-19 survivors 6-months after hospitalization the association between 25(OH)vitamin D levels and Long-COVID.

Methods: Long-COVID was defined according to NICE-guidelines. Fifty Long-COVID and 50 non-Long-COVID subjects matched on a 1:1-basis were enrolled from an outpatient-post-COVID clinic-cohort seen from August to November 2020. Therapies/comorbidities affecting calcium/vitamin-D/bone metabolism, and/or admission in ICU during hospitalization were exclusion criteria. 25(OH)vitamin D was measured at hospital-admission and 6-months after discharge.

Results: We observed lower 25(OH)vitamin D levels, evaluated at follow-up, in subjects with Long-COVID than those without (20.1vs23.2 ng/mL-p = 0.03). Regarding the affected health-areas evaluated in the entire cohort, we observed lower 25(OH)vitamin D levels in those with neurocognitive symptoms at follow-up (n.7) as compared to those without (n.93) (14.6vs20.6 ng/mL-p = 0.042). In patients presenting vitamin D deficiency (<20 ng/mL) both at admission and at follow-up (n.42), those affected by Long-COVID (n.22) presented lower 25(OH)vitamin D levels, at follow-up, compared to those not affected (n.20) (12.7vs15.2 ng/mL-p = 0.041). In multiple-regression analyses, lower 25(OH)vitamin D levels, at follow-up, resulted as the only variable significantly associated with Long-COVID in our cohort (p = 0.008, OR 1.09-CI 1.01-1.16).

Conclusions: COVID-19 survivors with Long-COVID have lower 25(OH)vitamin D levels as compared to matched-patients without Long-COVID. Our data suggest that vitamin D levels should be evaluated in COVID-19 patients after hospital-discharge. Role of vitamin D supplementation as preventive strategy of COVID-19 sequelae should be tested in randomized-controlled trials.

Source: di Filippo L, Frara S, Nannipieri F, Cotellessa A, Locatelli M, Rovere Querini P, Giustina A. Low vitamin D levels are associated with Long COVID syndrome in COVID-19 survivors. J Clin Endocrinol Metab. 2023 Apr 13:dgad207. doi: 10.1210/clinem/dgad207. Epub ahead of print. PMID: 37051747. https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgad207/7116659 (Full text available as PDF file)

Long COVID in the Older Adult and Vitamin D

Abstract:

Background: The coronavirus COVID-19 strain that emerged in December 2019 continues to produce a widespread and seemingly intractable negative impact on health and longevity and life quality in all parts of the world, especially, among older adults with chronic health conditions.

Objectives: The first aim of this updated review article was to examine, summarize, synthesize, and report on the research base concerning the possible use of vitamin D in the realm of the recently emergent syndrome termed long or post-acute COVID-19 disease. A second was to establish any health associated preventive and intervention recommendations for the older adult with long COVID-19 manifestations, who may yet be susceptible to future COVID-19 variant infections and others.

Methods: To examine the association between vitamin D and long COVID-19 illness manifestations, articles responding to several key words entered into leading data bases were examined: These included the terms: Vitamin D, Long/Post-Acute COVID-19 and/or COVID-19. Databases employed were PUBMED, PubMed Central and Google Scholar. All relevant articles were carefully examined and those meeting the review criteria were carefully read, and described in narrative form.

Results: Data reveal some possible benefits may accrue in the context of COVID-19 illness prevention and rehabilitation by efforts to ensure optimal vitamin D serum levels among high risk, vitamin D deficient, and chronically challenged post-acute COVID-19 older adults.

Conclusion: More rigorous and carefully construed research efforts to examine vitamin D implications and its moderating or mediating role in averting or mitigating long COVID-19 health complications are strongly warranted.

Source: Ray Marks (2023) Long COVID in the Older Adult and Vitamin D. J Gerontol Geriatr Med 9: 155. https://www.heraldopenaccess.us/openaccess/long-covid-in-the-older-adult-and-vitamin-d (Full text)

Prevalence of vitamin D deficiency among patients attending Post COVID-19 follow-up clinic: a cross-sectional study

Abstract:

Objective: Post-COVID-19 syndrome appears to be a multi-organ illness with a broad spectrum of manifestations, occurring after even mild acute illness. Limited data currently available has suggested that vitamin D deficiency may play a role in COVID-19 cases. However, to our knowledge, no study has examined the frequency of vitamin D deficiency in post-COVID-19 cases and its effect on the symptom severity. The aim of this study is to both screen the frequency of vitamin D deficiency in post-COVID-19 syndrome patients and to study its relation to persistent symptoms.

Patients and methods: A cross-sectional, single-center study was conducted involving all cases attending post-COVID-19 follow-up clinic from November 2020 to May 2021. Complete history, clinical examination, and laboratory analysis [kidney functions, serum calcium, C-reactive protein, serum ferritin, Serum 25-(OH) vitamin D] was done as well as HRCT chest.

Results: The study included 219 post-COVID-19 cases, 84% had deficient vitamin D levels (< 20 ng/dL); 11.4% had insufficient level (20-30 ng/dL) and only 4.9 % reported normal level. There was no link between levels of vitamin D with either the acute or post-COVID-19 symptoms in the studied groups.

Conclusions: Despite the prevalence of vitamin D deficiency among the study population, no association was observed between the levels of vitamin D and post-COVID-19 symptoms. It appears that post-COVID-19 syndrome pathophysiology involves a more complex interaction with the immune system. Dedicated clinical trials are advised to better study vitamin D levels and the related disease severity in COVID-19 patients.

Source: Mohamed Hussein AAR, Galal I, Amin MT, Moshnib AA, Makhlouf NA, Makhlouf HA, Abd-Elaal HK, Kholief KMS, Abdel Tawab DA, Kamal Eldin KA, Attia AM, Othman AEA, Shah J, Aiash H. Prevalence of vitamin D deficiency among patients attending Post COVID-19 follow-up clinic: a cross-sectional study. Eur Rev Med Pharmacol Sci. 2022 Apr;26(8):3038-3045. doi: 10.26355/eurrev_202204_28635. PMID: 35503606. https://www.europeanreview.org/article/28635 (Full text)

Vitamin D status in chronic fatigue syndrome/myalgic encephalomyelitis: a cohort study from the North-West of England

Abstract:

OBJECTIVE: Severe vitamin D deficiency is a recognised cause of skeletal muscle fatigue and myopathy. The aim of this study was to examine whether chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is associated with altered circulating vitamin D metabolites.

DESIGN: Cohort study.

SETTING: UK university hospital, recruiting from April 2014 to April 2015.

PARTICIPANTS: Ninety-two patients with CFS/ME and 94 age-matched healthy controls (HCs).

MAIN OUTCOME MEASURES: The presence of a significant association between CFS/ME, fatigue and vitamin D measures.

RESULTS: No evidence of a deficiency in serum total 25(OH) vitamin D (25(OH)D2 and 25(OH)D3 metabolites) was evident in individuals with CFS/ME. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis revealed that total 25(OH)D was significantly higher (p=0.001) in serum of patients with CFS/ME compared with HCs (60.2 and 47.3 nmol/L, respectively). Analysis of food/supplement diaries with WinDiets revealed that the higher total 25(OH) vitamin D concentrations observed in the CFS/ME group were associated with increased vitamin D intake through use of supplements compared with the control group. Analysis of Chalder Fatigue Questionnaire data revealed no association between perceived fatigue and vitamin D levels.

CONCLUSIONS: Low serum concentrations of total 25(OH)D do not appear to be a contributing factor to the level of fatigue of CFS/ME.

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Source: Earl KE, Sakellariou GK, Sinclair M, Fenech M, Croden F, Owens DJ, Tang J, Miller A, Lawton C, Dye L, Close GL, Fraser WD, McArdle A, Beadsworth MBJ. Vitamin D status in chronic fatigue syndrome/myalgic encephalomyelitis: a cohort study from the North-West of England. BMJ Open. 2017 Nov 8;7(11):e015296. doi: 10.1136/bmjopen-2016-015296  https://www.ncbi.nlm.nih.gov/pubmed/29118054

Effect of intermittent vitamin D3 on vascular function and symptoms in chronic fatigue syndrome–a randomised controlled trial

Abstract:

BACKGROUND AND AIMS: Low 25-hydroxyvitamin D levels are common in patients with chronic fatigue syndrome; such patients also manifest impaired vascular health. We tested whether high-dose intermittent oral vitamin D therapy improved markers of vascular health and fatigue in patients with chronic fatigue syndrome.

METHODS AND RESULTS: Parallel-group, double-blind, randomised placebo-controlled trial. Patients with chronic fatigue syndrome according to the Fukuda (1994) and Canadian (2003) criteria were randomised to receive 100,000 units oral vitamin D3 or matching placebo every 2 months for 6 months. The primary outcome was arterial stiffness measured using carotid-femoral pulse wave velocity at 6 months. Secondary outcomes included flow-mediated dilatation of the brachial artery, blood pressure, cholesterol, insulin resistance, markers of inflammation and oxidative stress, and the Piper Fatigue scale. As many as 50 participants were randomised; mean age 49 (SD 13) years, mean baseline pulse wave velocity 7.8 m/s (SD 2.3), mean baseline office blood pressure 128/78 (18/12) mmHg and mean baseline 25-hydroxyvitamin D level 46 (18) nmol/L. 25-hydroxyvitamin D levels increased by 22 nmol/L at 6 months in the treatment group relative to placebo. There was no effect of treatment on pulse wave velocity at 6 months (adjusted treatment effect 0.0 m/s; 95% CI -0.6 to 0.6; p = 0.93). No improvement was seen in other vascular and metabolic outcomes, or in the Piper Fatigue scale at 6 months (adjusted treatment effect 0.2 points; 95% CI -0.8 to 1.2; p = 0.73).

CONCLUSION: High-dose oral vitamin D3 did not improve markers of vascular health or fatigue in patients with chronic fatigue syndrome.

TRIAL REGISTRATION: www.controlled-trials.com, ISRCTN59927814.

Copyright © 2014 Elsevier B.V. All rights reserved.

 

Source: Witham MD, Adams F, McSwiggan S, Kennedy G, Kabir G, Belch JJ, Khan F. Effect of intermittent vitamin D3 on vascular function and symptoms in chronic fatigue syndrome–a randomised controlled trial. Nutr Metab Cardiovasc Dis. 2015 Mar;25(3):287-94. doi: 10.1016/j.numecd.2014.10.007. Epub 2014 Oct 22. https://www.ncbi.nlm.nih.gov/pubmed/25455721

 

Will vitamin D supplementation ameliorate diseases characterized by chronic inflammation and fatigue?

Abstract:

Chronic NF-κB activation has been supposed as a key event in chronic fatigue syndrome (CFS) and many other better-defined pro-inflammatory diseases. Knowledge about the impact of deficiency vitamin D on chronic NF-κB activation could open a new disease approach. Whereas NF-κB activation leads at first to a pro-inflammatory immune response, later on a vitamin D-dependent anti-inflammatory response ensues. Binding of the active vitamin D metabolite 1,25(OH)(2)D(3) to vitamin D receptor (VDR) yields a transcription factor which represses NF-κB activation, and additionally modulates and down-regulates adaptive, but enhances innate immune responses, and improves redox balance, thus counterbalancing inflammation on multiple levels. However, this built-in late counterbalance against inflammation works only when stores of calcium and 25(OH)D(3) are abundant. Therefore a connection between lowered vitamin D-metabolism and persistent NF-κB activation, augmented nitrosative-oxidative stress, redox imbalance, chronic inflammation, and concomitant fatigue can be postulated. In order to confirm this hypothesis, randomized controlled clinical studies about the clinical effects of supplementation of calcium and vitamin D(3) would be necessary in diseases characterized by persistent NF-κB activation and chronic inflammation and fatigue.

Copyright © 2010 Elsevier Ltd. All rights reserved.

 

Source: Hoeck AD, Pall ML. Will vitamin D supplementation ameliorate diseases characterized by chronic inflammation and fatigue? Med Hypotheses. 2011 Feb;76(2):208-13. doi: 10.1016/j.mehy.2010.09.032. Epub 2010 Oct 25. https://www.ncbi.nlm.nih.gov/pubmed/20980105