Patients and procedures: A single-blind randomized controlled open-label clinical trial was conducted. We included patients with moderate COVID-19 who needed hospitalization and additional oxygen, ranging in age from 1 month to 17 years. They were randomly divided into two groups: the group receiving VD doses of 1,000 IU/day for children under 1 years old and 2,000 IU/day for children 1 to 17 years old, and the group not receiving VD (control). The outcome factors were the progression of oxygen requirement, the development of complications, and mortality.
Analysis of data: To compare groups, we used the Mann-Whitney U test, Fisher's exact test, and the chi-squared test. The number needed to treat (NNT) and absolute risk reduction (ARR) were computed. Statistics p ≤ 0.05 were deemed significant.
Results: 87 patients who met the trial's eligibility requirements between 24 March 2020 and 31 March 2021 were enrolled; 45 of them were randomly assigned, 20 to the VD group and 25 to the control group. Serum VD levels (median 13.8 ng/ml in the VD group and 11.4 ng/ml in the control group) and other general characteristics were similar at baseline.
Outcomes: 2/20(10%) patients in the VD group advanced to a superior ventilation modality compared to 9/25(36%) patients in the control group (p=0.10); one patient in the VD group died(5%) compared to 6(24%) patients in the control group (p= 0.23).For progression, the ARR was 26% (95% CI 8.8 to 60.2%) and the NNT was 3 (2 to 11), whereas the ARR for mortality was 19% (95% CI 3.9 to 42.8%) and the NNT was 6 (2 to 26). No patients getting VD had any negative effects. Since none of the patients had normal levels after obtaining the findings of the basal VD readings, the experiment was terminated for ethical concerns.
Conclusion: According to this study, juvenile patients who use VD supplements appear to have a lower risk of COVID-19 mortality and progression. These results need to be confirmed by other research.
Introduction There is no authorized, efficient therapy for COVID-19 in pediatric hospital patients as of yet. The majority of the consensus recommendations and published guidelines call for supportive treatments, extra oxygen, and the use of corticosteroids in select patients with respiratory impairment (1, 2). Since the start of the COVID-19 pandemic, a number of treatments have been investigated, including interleukin (IL)-6 inhibitors, convalescent plasma, azithromycin, ivermectin, lopinavir/ritonavir, and chloroquine or hydroxychloroquine. However, none of these treatments have demonstrated efficacy and safety in children. Nevertheless, some recommendations argue for the use of remdesivir in critically sick patients despite the fact that the evidence in pediatric patients is negligible and of low quality (3, 4).
Children of school age account for the majority of COVID-19 instances among pediatric patients, and they often have a moderate course. Unfinished theories exist on the disease's benign behavior. It has been hypothesized that regular exposure to viral infections while a child is still developing helps boost their immune system and improves their ability to fight against coronavirus 2 that causes severe acute respiratory syndrome (SARS-CoV-2). A high level of ACE-2 expression is more likely to be helpful than harmful in lung injury, according to mounting research. Angiotensin-converting enzyme 2 (ACE2) is a receptor through which SARS-CoV-2 enters the host cells. Infancy has a peak in ACE-2 expression, which thereafter declines as people age (6, 7).The reported lethality was high in an analysis of patients in Mexico City who needed hospital treatment, even though many of the cases in children were mild (8), especially in the presence of comorbidities (9).
Infectious illness pathogenesis is influenced by vitamin D (VD) (10). Innate antigen-presenting cells (APCs), dendritic cells (DCs), and monocytes are significant targets for the immunomodulatory effects of VD in addition to directly combating microbes. Because they convey antigens to T and B cells and can influence them with immunogenic signals including cytokines and the production of co-stimulatory molecules, APCs are crucial for starting the adaptive immune response (11, 12). The function and morphology of DCs can be changed by calcitriol and its analogs to produce a more tolerogenic immature state (13, 14), according to many investigations. Calcitriol has also been shown to produce comparable receptors on monocytes and to block T-cell cytokines including IL-2 and IL-17 (15). Additionally, VD enhances the production of the antimicrobial peptide cathelicidin in the respiratory epithelium during respiratory infections (16), which has been demonstrated to lessen the severity of the illness and influenza virus multiplication in vitro (17).
Conclusions have been limited by a small sample size, a short trial duration, and a dearth of laboratory-confirmed results, despite the fact that several randomized controlled trials (RCTs) have attempted to evaluate the impact of VD supplementation on the prevention of respiratory tract infections (18–21). A comprehensive assessment of seven clinical studies involving children revealed no link between VD supplementation and the prevention of pediatric acute respiratory infections (22).
Numerous observational studies have demonstrated not only that hospitalized COVID-19 patients had low levels of 25-hydroxyvitamin D3, but also that levels and illness severity are inversely correlated (23–26). RCTs have been conducted as a result to assess the effectiveness of VD administration; to far, these studies have been conducted on adult patients with varying degrees of success (27–29).
In this study, hospitalized children with COVID-19 were compared to the standard of treatment to determine the effectiveness and safety of the VD supplementation (doses of 1,000 IU/day for infants under 1 year and 2,000 IU/day for children 1 to 17 years old).
Patients and methods In the Pediatric Hospital, National Medical Center, XXI Century, a randomized controlled single-blind clinical experiment was conducted under open-label conditions. One of three pediatric hospitals in Mexico City authorized to treat COVID-19 kids during the COVID-19 pandemic was this hospital, which serves as a tertiary care facility for the Mexican Social Security Institute (IMSS). The hospital had 184 beds and two intensive care units prior to the remodeling (neonatal and pediatric). In order to accommodate patients with SARS-CoV-2 infection, a unique in-patient facility with 6 beds and one area with 40 beds were made available. No matter whether they had health insurance or not, all patients with severe respiratory illnesses or suspected SARS-CoV-2 infections were examined at the emergency room.
The Institutional Review Board (R-2020-3603-20) gave its blessing to this protocol, which was then entered into ClinicalTrials.gov under the registration number NCT04502667. The Declaration of Helsinki's ethical precepts guided the conduct of this trial. The signed informed permission was given by all of the participants' parents or legal guardians. Assent was also required for kids older than 8 years old. The Consolidated Standards of Reporting Trials (CONSORT) protocol was used in this investigation.
Between 24 March 2020 and 31 March 2021, patients were accepted. Patients under the age of 18 who had a real-time reverse transcription-PCR (rRT-PCR) diagnosis of SARS-CoV-2 infection and required hospitalization and supplementary oxygen met the following inclusion criteria. Patients who did not receive at least 7 days of VD supplementation were not included in the final analysis. Exclusion criteria were as follows: VD supplementation during the preceding 7 days or enteral feeding contraindications.
Between 24 March 2020 and 31 March 2021, patients were accepted. Patients under the age of 18 who had a real-time reverse transcription-PCR (rRT-PCR) diagnosis of SARS-CoV-2 infection and required hospitalization and supplementary oxygen met the following inclusion criteria. Patients who did not receive at least 7 days of VD supplementation were not included in the final analysis. Exclusion criteria were as follows: VD supplementation during the preceding 7 days or enteral feeding contraindications.
Intervention The VD group (VDG) or the control group (CG), which did not receive VD, was randomly allocated to patients in a 1:1 allocation ratio. Children under the age of one year received doses of 1,000 IU/day (One Drop® Teriana Labs SA de CV, Mexico) and children aged one to seventeen years received doses of 2,000 IU/day (Histofil®, Medix Labs SA de CV, Mexico) during hospitalization for a minimum of seven days and a maximum of fourteen days. Using online software, randomization was carried out.(Randomizer for Research: www.randomizer.org) by an investigator who had no interaction with the subjects. The assignment hierarchy was protected by one of the researchers. He monitored giving the sealed envelope to the attending doctors each time a new patient was added so they could assign the appropriate technique.
The severity of the illness was categorized as follows: (a) mild, in cases of fever, asthenia, symptoms consistent with an upper respiratory infection, but without respiratory distress or instrumental evidence of pneumonia; (b) moderate, in cases of respiratory distress, reduced nutrition and hydration, and/or instrumental evidence of pneumonia; (c) critical if there is acute respiratory distress syndrome (ARDS), multiorgan failure (MOF), septic shock, or coma; (d) severe if there is severe respiratory distress and/or desaturation (oxygen saturation (SpO2) 92% in ambient air); and/or intermittent cyanosis or apnea and/or systemic symptoms, such as lethargy, dehydration, convulsions, or suspected sepsis (30).
Experimental Biomarkers We compared the levels of C-reactive protein (CRP), D-dimer (DD), and fibrinogen upon admission and on the seventh day of hospitalization. The technique reported in a research by Van Den Ouweland et al. (27) was used to assess the blood concentration of 25-hydroxyvitamin D3 using a Waters ACQUITY UPLC Class linked to a Xevo TQD (Waters, Milford, Massachusetts, USA), with an APCI Ion SABER II probe.Used was a solid-phase extraction cartridge from Phenomenex (Strata C18-E; 55 m, 70 A). Using a C18 column at 50°C, chromatographic studies were carried out (Kinetex 1.7 m XB-C18 100 A LC Column 50 mm 2.1 mm, Phenomenex, California, USA). Masslynx version 4.1 software was used for data collection and analysis (Waters). In a subsample of serum specimens, the 25-hydroxyvitamin D3 was examined twice, and the coefficient of variance was 5.16%. When the serum level was between 20 and 29.99 ng/ml, it was regarded to be insufficiency, and when it was between 30 and 60 ng/ml, it was considered to be normal (31).
A certified COVID-19 laboratory used the standardized protocol to establish the laboratory diagnosis of SARS-CoV-2 infection by rRT-PCR in accordance with the Standardized Guidelines for Epidemiological Surveillance (32).
The determinants for the result were the progression of oxygen use, the emergence of complications, and death. Anorexia, vomiting, stomach discomfort, diarrhea, headaches, disorientation, constipation, muscular weakness, and rashes were among the negative consequences of VD that were tracked. The use of supplements was immediately stopped if any of the symptoms linked to the administration of VD appeared. Throughout their hospital stay, patients were monitored from the time of admission until their discharge or demise.
Statistical evaluation The sample size was established by considering that, compared to the control group, COVID-19-infected patients who do not get VD doses had a higher relative risk (RR) of 1.67 of developing severe COVID-19 or dying. An average of 59 patients per group were present.SPSS version 24.0 was used for the statistical analysis (IBM Incorporation). Since quantitative variables did not exhibit a normal distribution, they are given as medians and interquartile ranges (IQRs), while qualitative variables are expressed as proportions. We utilized the Mann-Whitney U test, Fisher's exact test, and the chi-squared test to compare the groups. To ascertain how changes in laboratory indicators were impacted by VD supplementation, a multiple regression model was used. Intention to treat analysis was also used to determine the number needed to treat (NNT) and absolute risk reduction (ARR). Statistics were deemed significant at p 0.05.
Results 697 patients who fit the operational criteria of a suspected case of COVID-19 were assessed between March 24, 2020, and March 31, 2021. A total of 260 individuals had positive rRT-PCR results; of these, 173 had moderate illness and received outpatient care (66.6%), while 87 required hospitalization (33.4%). The median age of the 87 hospitalized patients was 12 years (12 months to 17 years), 64.4% of them were men, and 81% of them had at least one comorbid condition. Of the eligible patients, 42 were disqualified because they did not match the inclusion criteria (not requiring supplemental oxygen). Twenty individuals were assigned to the VDG and 25 to the CG out of the remaining 45 patients.Due to a negative rRT-PCR test, 2/20 patients were excluded from the VDG. Four CG patients did not complete the intervention because they were released before the seventh day of hospitalization, and one patient got a VD supplement for around seven days. Consequently, the final analysis comprised 21 patients from the CG and 17 individuals from the VDG (Figure 1).
Participants were mostly female, with a median age of 13.9 years for those in the CG and 10.6 years for those in the VDG. It is remarkable that about half of both groups had obesity. In addition to obesity, 45% of patients receiving VD supplementation (n = 9) also had comorbid conditions, the most common of which were cancer and gastrointestinal diseases (five and four patients, respectively). In contrast, 72% of patients in the control group (n = 18) had comorbid conditions, the most common of which was cancer (six patients), followed by respiratory chronic disease (four patients). Table 1 demonstrates that there was no variation in participant characteristics across the groups, with the exception of COVID-19 severity. In comparison to the VDG (15%), the CG (56%), had a larger percentage of severe and critical patients (p = 0.03).
Table1
Coughing and respiratory discomfort were the primary clinical features, and a physical examination revealed pneumonia. The 45 patients allocated to the intervention had an X-ray upon admission; the most common radiological findings were bilateral micromacronodular infiltrates, bilateral peripheral small opacities, reticular pattern, and reticular pattern (17.7% each), followed by glass-ground opacities (3.6%). Air bronchogram (11.1%), cardiomegaly (6.6%), increased pulmonary flow (4.4%), and pleural effusion (2.2%) were among the other findings, however these were linked to underlying diseases. Five individuals, or up to 11.1%, had a normal X-ray. The characteristics of each group are displayed individually in Table 2. Due to the fact that some patients had multiple findings, the number of modifications is larger than the total number of patients.
Table 2
The baseline sample of 45 patients' vitamin D levels revealed VD inadequacy, with a median of 11.7 ng/ml (IQR 9.4-17.22 ng/ml). Only four patients had a level that was inadequate. None of the patients had a level that was normal. In comparison to the control group, which had a median level of 11.4 ng/ml (IQR 8.7-13.1 ng/ml), the VDG had a median level of 13.8 ng/ml (IQR 10.75-18.35 ng/ml).
This caused an ethical dilemma, thus it was agreed to halt the experiment and provide VD to every patient with COVID-19 who was admitted to the hospital in accord with the scientists and the ethics committee.
Outcomes and management
According to Table 3, support therapy for the two groups was quite similar. Assisted mechanical breathing and intensive care were necessary for patients with severe and critical illnesses; these events happened more often in the control group (56 vs. 15%). The usage of corticosteroids, an antibiotic, was comparable between groups. Five individuals received oseltamivir prescriptions.
Table 3
Compared to nine patients in the control group, only two patients in the VD group advanced to a better ventilation modality. This led to a number needed to treat (NNT) of 3 and an absolute risk reduction (ARR) of 26% (95% CI 8.8-60.2%). (2 to 11).
In terms of mortality, there was one death (associated with COVID-19) in the VDG group as opposed to six fatalities in the CG, of which two were attributable to severely sick patients. Two deaths were connected to the underlying disease, and four deaths were connected to COVID-19. The NNT was 6 and the ARR was 19% (95% CI: 3.9 to 42.8%). (2 to 26).
Malnutrition (undernutrition and obesity) was more prevalent in patients who advanced to a better ventilator modality than in kids with a normal nutritional status (28.5 vs. 10%), while the difference was not statistically significant (p = 0.22). Only one of the seven deceased patients had normal nutritional condition.
None of the vitamin D-treated subjects had any medication-related adverse reactions.
The median number of days the VDG spent in the hospital was fewer (9 days) than it was for the group receiving standard of care therapy (median 11 days).
Laboratory markers
laboratory indicators
On the seventh day, the baseline CRP value was seen to drop in the VDG (97.9 vs. 3.0 mg/l, p = 0.007) but not in the control group (44.3 vs. 34.9 mg/l, p = 0.683). Comparisons are challenging since not all patients had baseline and follow-up data. Patients in the VD group saw a significant increase in CRP value at 24 hours, with a median of 143.7 mg/l (ranging from 76 mg/l to 243 mg/l). The DD and fibrinogen were identical. VD was shown to lower blood values of CRP in the linear regression model [coefficient 71.9 (95% CI 139.0 to 4.8), p = 0.037] (Table 4, Figure 2).
Table 4
Discussion
According to the majority of research, SARS-CoV-2 infection in previously healthy children progresses favorably and without complications, however patients with chronic illnesses or underlying problems run the risk of developing severe COVID-19 and passing away as a result. In order to ascertain if certain methods used to treat other viral respiratory infections are also beneficial for COVID-19 in children, it is important to recognize and assess treatment approaches in various settings.
One of the first RCTs to assess the efficiency of VD supplementation to enhance the clinical circumstances of kids with COVID-19 who need to be hospitalized. The results seem to show that there is some benefit from VD, since there were fewer patients who progressed in disease severity and died.
Ramírez-Sandoval et al. (33) found that in a cohort of 2,908 Mexican adult patients with COVID-19, only 19.6% showed VD deficiency (<12.5 ng/ml) and 36% had levels between 12.5 and 20 ng/ml, different from our study, where age alone appears to be a risk factor for vitamin D deficiency. Rustecka A et al. also found in 1,472 children from Poland that the proportion of children with VD deficiency increased after several months of the COVID-19 pandemic (34) similar to the study by Kang et al. (35) in Seoul, Korea. In contrast, Meoli M et al. compared VD levels with data previously obtained in 473 adolescents and young adults in Switzerland, in the period 2014–2016, with a new group of young people (298, aged 18–19 years) in the period from July to December 2020, and found no difference in VD insufficiency (36). Alpcan et al. (37) in Turkey found that the serum VD level was significantly lower in a group of 75 hospitalized COVID-19 pediatric patients compared to the control group of 80 healthy children (21.5 ± 10.0 vs. 28.0 ± 11.0 IU, p < 0.001).
The role of VD in immune defense in COVID-19 has been studied, with different mechanisms taking part, such as the formation of an antimicrobial peptide in the respiratory epithelium (cathelicidin), producing chemotaxis-activating β defensins, differentiation of monocytes in macrophages, as well as the activation of oxidative pathways in monocytes and macrophages, an important antiviral mechanism, modulates the expression of pattern recognition receptors, interrupting local inflammation and releasing chemokines, inhibits the secretion of IL-12, IL-23, IL-10, as well as the expression of major histocompatibility complex (MHC) class II molecules and stimulators, such as CCL4 and CCL19, decreasing the inflammatory response (38).
Vitamin D supplementation in adult patients has been evaluated in RCTs, both as a prevention of disease acquisition and as an adjuvant for the improvement of hospitalized patients. Karonova et al. (39) analyzed the potential effect of vitamin D supplementation in reducing SARS-CoV-2 infection morbidity and severity in healthcare workers, but neither vitamin D intake nor vitamin D deficiency/insufficiency was associated with a decrease in SARS-CoV-2 morbidity [odds ratio (OR) 2.27; 95% CI, 0.72 to 7.12]. Meanwhile, Murai et al. reported that the hospital length of stay of patients with COVID-19 was similar between those who received a high single VD dose compared to those who did not receive a high single VD dose (40). In contrast, Nogues X et al. found that weekly high-dose calcifediol decreased severity and mortality in patients with COVID-19 (41).
Available systematic reviews and meta-analyses have not reached definitive conclusions. In the meta-analysis published in a study by Oscanoa TJ et al. (42), which included 23 studies (n = 2,692 subjects, predominantly male adults), it was found that vitamin 25(OH)D deficiency was associated with an increased risk of severe COVID-19 (RR 2.00; 95% CI 1.47–2.71, 17 studies) and mortality (RR 2.45; 95% CI 1.24–4.84, 13 studies). In a later meta-analysis, including six RCTs (551 adult patients with COVID-19), the results suggest an overall beneficial effect of VD treatment when all the observations across all the RCTs were pooled as an overall effect size. The authors consider that the difference in the studies settings, timings, randomization, blinding, and data collection strategies could have influenced the outcomes (43).
Specifically, in the pediatric population, the systematic review conducted by Shah K et al. (44) aimed to estimate the prevalence of VD deficiency in pediatric patients with COVID-19 and the association between VD deficiency and disease severity, as well as the relationship between VD supplementation and improvement. Eight eligible studies (two reviews) were included in the review. Meta-analysis of the six studies showed a prevalence of VD deficiency of 45.91% (95% CI 25.14–67.45). The analysis of two studies showed that low VD levels increased the risk of severe disease (OR 5.5; 95% CI 1.56–19.51, p = 0.008). Due to limited and heterogeneously published literature, the effect of VD supplementation on COVID-19 infectivity and severity could not be explored, but authors consider that needs to be evaluated as a preventive measure in pediatric patients with COVID-19.
Probably, the benefit we observed in our population was due to the fact that most had VD deficiency and the impact of supplementation on severe COVID-19 was greater than reported in other studies where the percentage of the deficiency was lower.
One aspect to consider is the design of the study; although it was an open-label RCT without a placebo, the outcome measures were blindly evaluated. Daily monitoring of each patient was performed by the same two investigators, thereby achieving a standardized assessment. Other strengths of the present study are that all the patients but one in the group that received VD had complete therapeutic compliance and that there were no losses to follow-up.
Although there seems to be a beneficial effect of vitamin D supplementation, we must consider the study limitations. Undoubtedly, the main limitation was not having completed the sample size due to ethical reasons, which most likely conditioned that some variables were not distributed homogeneously between groups, such as the severity of COVID-19, comorbidities (e.g., pulmonary disease), as well as in the values of laboratory markers. Another limitation was that the serum levels of vitamin D were not quantified at the end of this study.
There is still no conclusive evidence to support the recommendation of vitamin D supplementation more than two years after the COVID-19 epidemic began and despite an enormous volume of published information on the subject. Although the results of various research appear to favor vitamin D treatment in high-risk patients, the findings are still contradictory. A new blood vitamin D cutoff point should be adopted to reduce dangers for the individuals. In this investigation, vitamin D deficiency (serum level 20 ng/ml) or insufficiency (level between 20 and 29.99 ng/ml) were defined using the parameters set by the Endocrine Society (45). Children with insufficiency (level between 12 and 20 ng/ml) might participate in a new trial if the criteria changed using the Food and Nutrition Board's values, and only patients with vitamin D deficiency (12 ng/ml) would be excluded. Several suggestions are provided for more study in the current review by Briceno Noriega et al (46).
