SARS-CoV-2 in Mexico: An Association Among Geography, Comorbidities, and Vitamin D Deficiency.

Objective: The aim of this study was to determine the association among temperature, relative humidity, latitude, vitamin D content and comorbidities in the spread of SAR-CoV-2 in Mexico in 2 different waves. Methods: The data on SARS-CoV-2 infections and comorbidities were obtained from the Mexican entities with the highest number of positive cases and deaths in the 2 waves that have most damaged the population. Results: Low temperature, high relative humidity, vitamin D deficiency and high percentage of comorbidities were factors that correlated with a high spread of SARS-CoV-2. Interestingly, 73.8% of the population had one of the most common comorbidities that favor the spread of the virus. Conclusion: The high percentage of comorbidities and the deficient concentration of vitamin D were determining factors in the high number of infections and deaths in Mexico. Furthermore, weather conditions could contribute to and alert to the spread of SARS-CoV-2.

COVID-19 and Other Pleiotropic Actions of Vitamin D: Proceedings from the Fifth International Conference "Vitamin D-Minimum, Maximum, Optimum" under the Auspices of the European Vitamin D Association (EVIDAS).

Vitamin D deficiency appeared as a worldwide pandemic markedly earlier than the COVID-19 pandemic was announced in global media [...].

A Retrospective Chart Review Evaluating Changes in 25-Hydroxyvitamin D Levels among Patients Attending the University Healthcare Centre during the COVID-19 Pandemic.

COVID-19-pandemic-related home confinement aids in limiting the spread of the virus but restricts exposure to sunlight, thereby possibly affecting 25(OH)D concentrations. This study aimed to investigate the effect of lockdown measures on 25(OH)D levels in outpatients visiting the healthcare centre over a period of two years. In this retrospective chart review, outpatients who visited a university healthcare centre for a health check-up over a period of two years were included. The patients' 25(OH)D serum levels and status were compared before, during, and after the lockdown periods. A total of 7234 patients were included in this study, with a mean age of 34.66 ± 16.78. The overall prevalence of 25(OH)D insufficiency, deficiency and sufficiency was 33.8%, 30.7% and 35.4%, respectively. The proportion of individuals with 25-(OH) D deficiency prior to lockdown was 29% and this proportion increased in the lockdown and post-lockdown periods to 31.1% and 32%, respectively. Although gender was less likely to have an impact on the 25 (OH) D level during the lockdown period (p = 0.630), we found an association between gender and 25 (OH) D status in the pre-lockdown and post-lockdown periods (p < 0.001 and p < 0.001, respectively). Another association between nationality and 25 (OH)D levels was found before, during and after the lockdown periods (p < 0.001). In addition, the youngest population, aged between 1 and 14, was strongly affected by the home confinement. Age had a positive and significant (p < 0.05) effect on 25 (OH) D status regardless of the different periods. Moreover, in the pre-lockdown period, male outpatients had 1.56 chance of having a sufficient level of 25 (OH)D. However, during the lockdown period, this chance decreased to 0.85 and then increased to 0.99 after the lockdown period. We found no statistically significant difference in the mean serum concentrations or in the prevalence of vitamin D insufficiency when we compared values from before, during and immediately after the COVID-19 lockdown period. However, there was a generally increased prevalence of vitamin D insufficiency in our study population. Another association between gender, nationality and age groups with 25(OH) D was found. Regular exposure to UVR is recommended for maintaining adequate vitamin D levels and to prevent vitamin D deficiency. Further research is needed to determine the best indications for vitamin D supplementation if confinement periods are extended and to consider the potential health consequences of prolonged confinement periods not only on vitamin D status but also on overall public health. The findings of this study may be considered by stakeholders for a targeted supplementation approach for risk groups.

Evaluation of 25-hydroxyvitamin D (25(OH)D) levels before and during the COVID-19 pandemic: A cross-sectional study and trend analysis involving 86,772 samples.

BACKGROUND: The aim of this paper was to evaluate the change in 25-hidroxyvitamin D (25(OH)D) levels before and during the COVID-19 pandemic. METHODS: In this retrospective, cross-sectional and methodological study included 86,772 patients (18-75 years) samples who were admitted to the Izmir Dokuz Eylul University Hospital (latitude and longitude (Turkey): 27 E 09; 38 N 25, respectively) for various reasons and whose 25(OH)D levels were measured in the biochemistry unit between 2019-2020 and 2020-2021 (before and during the COVID-19 outbreak). A time series analysis of monthly averages for 25(OH)D was performed. For the purpose of seasonal study, the mean levels of 25(OH)D are grouped by years. Data were modeled in terms of 25(OH)D levels using the MATLAB Curve Fitting Toolbox. RESULTS: There was no significant difference between the sexes according to 25(OH)D levels (p>0.05). 25(OH)D levels were significantly higher in the summer months and lower in the winter months (p<0.001). When comparing the spring months, 25(OH)D levels in 2020 (18 ± 10) were found to be significantly lower than in 2019 (22 ± 12) (p<0.001); on the contrary, when examined based on the summer, autumn, and winter months, it was determined that 25(OH)D levels increased in 2020 (summer: 25 ± 13, autumn: 25 ± 14, and winter: 19 ± 10) compared to 2019 (summer: 23 ± 11, autumn: 22 ± 10, and winter: 19 ± 11) (p<0.001). In the estimates curve obtained with an error margin of 11% in the time series analysis, it was estimated that the 25(OH)D averages after the pandemic would be similar to those before the pandemic. CONCLUSIONS: Restrictions, partial or complete closures, and curfews can significantly affect individuals' 25(OH)D levels during the COVID-19 outbreak. There is a need for multicenter studies with larger populations covering different regions to strengthen and support our results.

Vitamin D Levels in the Pre- and Post-COVID-19 Pandemic Periods and Related Confinement at Pediatric Age.

Coronavirus disease 2019 (COVID-19) restrictions have been correlated with vitamin D deficiency in children, but some uncertainties remain. We retrospectively studied vitamin 25-(OH) D blood levels in 2182 Italian children/adolescents hospitalized for various chronic diseases in the year before (n = 1052) and after (n = 1130) the nationwide lockdown. The type of underlying disease, gender, and mean age (91 ± 55 and 91 ± 61 months, respectively) of patients included in the two periods were comparable. Although mean levels were the same (p = 0.24), deficiency status affected a significantly higher number of subjects during the lockdown period than in the pre-COVID period (p = 0.03), particularly in summer (p = 0.02), and there was also a smoothing of seasonal variations in vitamin D levels. Particularly at risk were males (OR = 1.22; p = 0.03), the 1-5 year age group (OR = 1.57; p < 0.01) and the 6-12 year age group (OR = 1.30; p = 0.04). Infants appeared not to be affected (p = 1.00). In the post-COVID period, the risk of vitamin D deficiency was unchanged in disease-specific groups. However, the proportion of deficiency or severe deficiency differed significantly in the subgroup with endocrinopathy (higher; Chi-square p = 0.04), and with respiratory problems and obesity (lower; Chi-square p = 0.01 and p < 0.01, respectively). Conflicting/opposite literature results advocate for further studies to clearly indicate the need for supplementation during possible future periods of confinement.

Association of Vitamin D levels on the Clinical Outcomes of Patients Hospitalized for COVID-19 in a Tertiary Hospital.

Objectives: This study aimed to compare the severity of COVID-19, inflammatory parameters and clinical outcomes among patients with normal and subnormal levels of Vitamin D. Methodology: This is a retrospective cohort study of 135 patients admitted in a tertiary hospital for COVID-19. Patients were grouped according to their Vitamin D level. Primary outcome measure was the composite of all-cause mortality and morbidity. Other outcome measures determined were the comparison among the groups on the severity of COVID-19 infection, changes in inflammatory parameters, length of hospital stay and duration of respiratory support. Results: There was a significant trend of higher ICU admission (p=0.024), mortality (p=0.006) and poor clinical outcome (p=0.009) among the Vitamin D deficient group. No significant difference was found for most of the inflammatory parameters, duration of hospital stay and respiratory support. Overall, patients with deficient, but not insufficient Vitamin D level had 6 times higher odds of composite poor outcome than those with normal Vitamin D (crude OR=5.18, p=0.003; adjusted OR=6.3, p=0.043). Conclusion: The inverse relationship between Vitamin D level and poor composite outcome observed in our study suggests that low Vitamin D may be a risk factor for poor prognosis among patients admitted for COVID-19.

Reasons to avoid vitamin D deficiency during COVID-19 pandemic.

The effects of vitamin D on the musculoskeletal system are well established. Its deficiency causes osteomalacia, secondary hyperparathyroidism, and an increased risk for fractures and falls. However, clinical and experimental evidence points to extra-skeletal actions of vitamin D, including on immune and respiratory systems. Thus, during this COVID-19 pandemic, a possible deleterious role of vitamin D deficiency has been questioned. This paper aims to present a brief review of the literature and discuss, based on evidence, the role of vitamin D in the lung function and in the prevention of respiratory infections. Relevant articles were searched in the databases MEDLINE/PubMed and SciELO/LILACS. The mechanisms of vitamin D action in the immune system response will be discussed. Clinical data from systematic reviews and meta-analyses show benefits in the prevention of respiratory infections and improvement of pulmonary function when vitamin D-deficient patients are supplemented. At the time of writing this paper, no published data on vitamin D supplementation for patients with COVID-19 have been found. Vitamin D supplementation is recommended during this period of social isolation to avoid any deficiency, especially in the context of bone outcomes, aiming to achieve normal values of 25(OH)D. The prevention of respiratory infections and improvement of pulmonary function are additional benefits observed when vitamin D deficiency is treated. Thus far, any protective effect of vitamin D specifically against severe COVID-19 remains unclear. We also emphasize avoiding bolus or extremely high doses of vitamin D, which can increase the risk of intoxication without evidence of benefits.

Influence of Strict Lockdown on Vitamin D Deficiency in Pregnant Women: A Word of Caution.

The main source of vitamin D results from skin sunlight exposure. Vitamin D deficiency (VDD) is linked to several adverse events during pregnancy. While performing a cross-sectional study with 886 pregnant women in Elda (Spain) from September 2019 to July 2020 to determine the association of VDD with gestational diabetes mellitus in relation to body mass index, a strict lockdown (SL) due to the COVID-19 pandemic was declared from 15 March 2020 to 15 May 2020. To determine if VDD prevalence in the local population of pregnant women was influenced by SL, a retrospective cross-sectional study was conducted to estimate the prevalence odds ratio (POR) for the association of VDD and SL. A crude logistic regression model was calculated, and then further adjusted by the biweekly measured vitamin D-specific UVB dose in our geographical area. The POR during SL was 4.0 (95%CI = 2.7-5.7), with a VDD prevalence of 77.8% in the quarantine period. Our results revealed that VDD prevalence in pregnant women was influenced by SL. This valuable information could guide us in future if public officials order the population to stay indoors for any given reason.

Frequency of COVID-19 Infection as a Function of Vitamin D Levels.

BACKGROUND: It has been speculated that higher concentrations of 25-hydroxy-vitamin D (25OHD) provide some protection against COVID-19. We assessed whether there is any relationship between 25OHD concentrations and the subsequent development of COVID-19 infection. MATERIALS AND METHODS: Concentrations of 25OHD were measured in March-April 2020 in 134 healthy subjects (57 males), age range 6-50, from a single urban general practice in central Poland. Data on COVID-19 infection during the subsequent 12 months (prior to the vaccination program) were obtained from the national database of COVID-19 cases. None of the subjects received any 25OHD supplements. RESULTS: The average 25OHD concentrations were 18.1 ± 7.39 ng/mL (37.3% had 25OHD above 20 ng/mL). Thirty-one (23.1%) patients developed COVID-19 infection, but an increased risk was only observed in individuals with 25OHD concentrations below 12 ng/mL (COVID-19 infection in 11 out of 25 patients (44%) with 25OHD < 12 ng/mL versus 20 out of 109 (18.3%) for those with 25OHD above 12 ng/mL, p = 0.0063). Such a relationship was no longer observed for subjects with 25OHD concentrations above 20 ng/mL (p = 0.2787). CONCLUSIONS: Although only a minority of healthy subjects had 25OHD concentrations above 20 ng/mL in spring, an increased risk of subsequent COVID-19 infection was only observed in those with severe 25OHD deficiency (<12 ng/mL).

Low vitamin D levels predict outcomes of COVID-19 in patients with both severe and non-severe disease at hospitalization.

PURPOSE: Low vitamin D in COVID-19 have been related to worse outcomes. However, most of the studies conducted so far were not-controlled and retrospective, including biases potentially influencing this association. We evaluated 25(OH)vitamin D levels of patients with both severe and non-severe disease at hospital-admission, and in a cohort of control subjects. Moreover, we evaluated sACE-2 levels to investigate the mechanisms underlying the association between vitamin D and COVID-19. METHODS: COVID-19 patients were enrolled in a matched for age, sex and comorbidities 1:1-ratio based on the presence/or not of respiratory-distress/severe-disease at hospital-admission. Control matched subjects were enrolled from an outpatient-setting. RESULTS: Seventy-three COVID-19 patients (36 severe and 37 non-severe) and 30 control subjects were included. We observed a higher vitamin D deficiency (<20 ng/mL) prevalence in COVID-19 patients than control subjects (75% vs 43%). No differences were found regarding 25(OH)vitamin D and sACE-2 levels between patients with and without severe-disease at study entry. During the disease-course, in the severe group a life-threatening disease occurred in 17 patients (47.2%), and, in the non-severe group, a worsening disease occurred in 10 (27%). 25(OH)vitamin D levels, at admission, were negatively correlated with sACE-2 levels, and were lower in patients whose disease worsened as compared to those in whom it did not, independently from the disease severity at admission. In multivariate-analysis, lower 25(OH)vitamin D resulted as an independent risk factor for disease worsening. CONCLUSIONS: 25(OH)vitamin D levels at hospital-admission strongly predicted the occurrence of worsening outcomes in COVID-19 independently of the disease severity at presentation.

Influence of sunlight on the association between 25-hydroxyvitamin D levels and sleep quality in Brazilian adults: A population-based study.

OBJECTIVES: This study aimed to evaluate the association of vitamin D with sleep quality during the COVID-19 pandemic and the influence of daily sunlight on this association. METHODS: This cross-sectional, population-based study among adults stratified by multistage probability cluster sampling was conducted from October to December 2020 in the Iron Quadrangle region of Brazil. The outcome was sleep quality, evaluated by the Pittsburgh Sleep Quality Index. Vitamin D (25-hydroxyvitamin D) concentrations were determined by indirect electrochemiluminescence and a deficiency was classified as 25(OH)D < 20 ng/mL. To assess sunlight, the average daily sunlight exposure was calculated and was classified as insufficient when less than 30 min/d. Multivariate logistic analysis was used to estimate the association between vitamin D and sleep quality. A directed acyclic graph was used to select minimal and sufficient sets of adjustment variables for confounding from the backdoor criterion. RESULTS: In a total of 1709 individuals evaluated, the prevalence of vitamin D deficiency was 19.8% (95% CI, 15.5-24.9%), and the prevalence of poor sleep quality was 52.5% (95% CI, 48.6-56.4%). In multivariate analysis, vitamin D was not associated with poor sleep quality in individuals with sufficient sunlight. Moreover, in individuals with insufficient sunlight, vitamin D deficiency was associated with poor sleep quality (odds ratio [OR], 2.02; 95% CI, 1.10-3.71). Furthermore, each 1-ng/mL increase in vitamin D levels reduced the chance of poor sleep quality by 4.2% (OR, 0.96; 95% CI, 0.92-0.99). CONCLUSIONS: Vitamin D deficiency was associated with poor sleep quality in individuals with insufficient exposure to sunlight.

The interplay between hypovitaminosis D and the immune dysfunction in the arteriovenous thrombotic complications of the sever coronavirus disease 2019 (COVID-19) infection.

Thromboembolic complications including cerebrovascular accidents, pulmonary embolism, myocardial infarction, deep vein thrombosis and disseminating intravascular coagulopathy are serious encounters in sever coronavirus disease 2019 (COVID-19) infected patients. This worsens the prognosis and may lead to death or life long morbidities. The laboratory finding of the disturbed haemostasias and the hyperinflammatory response are almost invariably present in COVID-19 patients. Multiple treatment modalities are utilized by the healthcare professionals to overcome the cytokine storm, oxidative stress, endothelial dysfunction, and coagulopathy in these patients. The combined actions of vitamin D (VitD) as a steroid hormone with anti-inflammatory, immunomodulatory, and antithrombotic properties increase the potential of the possible involvement of hypovitaminosis D in the thromboembolic complications of COVID-19 infection, and stimulated researchers and physicians to administer VitD therapy to prevent the infection and/or overcome the disease complications. The current review highlighted the immunomodulatory, anti-inflammatory, antioxidative and hemostatic functions of VitD and its interrelation with the renin-angiotensin-aldosterone system (RAAS) pathway and the complement system. Additionally, the association of VitD deficiency with the incidence and progression of COVID-19 infection and the associated cytokine storm, oxidative stress, hypercoagulability, and endothelial dysfunction were emphasized. Normalizing VitD levels by daily low dose therapy in patients with hypovitaminosis D below (25 nmol/l) is essential for a balanced immune response and maintaining the health of the pulmonary epithelium. It protects against upper respiratory tract infections and decreases the complications of COVID-19 infections. Understanding the role of VitD and its associated molecules in the protection against the coagulopathy, vasculopathy, inflammation, oxidative stress and endothelial dysfunction in COVID-19 infection could lead to new therapeutic strategies to prevent, treat, and limit the complications of this deadly virus infection.

Vitamin D and COVID-19-Revisited.

Vitamin D, when activated to 1,25-dihydroxyvitamin D, is a steroid hormone that induces responses in several hundred genes, including many involved in immune responses to infection. Without supplementation, people living in temperate zones commonly become deficient in the precursor form of vitamin D, 25-hydroxyvitamin D, during winter, as do people who receive less sunlight exposure or those with darker skin pigmentation. Studies performed pre-COVID-19 have shown significant but modest reduction in upper respiratory infections in people receiving regular daily vitamin D supplementation. Vitamin D deficiency, like the risk of severe COVID-19, is linked with darker skin colour and also with obesity. Greater risk from COVID-19 has been associated with reduced ultraviolet exposure. Various studies have examined serum 25-hydroxyvitamin D levels, either historical or current, in patients with COVID-19. The results of these studies have varied but the majority have shown an association between vitamin D deficiency and increased risk of COVID-19 illness or severity. Interventional studies of vitamin D supplementation have so far been inconclusive. Trial protocols commonly allow control groups to receive low-dose supplementation that may be adequate for many. The effects of vitamin D supplementation on disease severity in patients with existing COVID-19 are further complicated by the frequent use of large bolus dose vitamin D to achieve rapid effects, even though this approach has been shown to be ineffective in other settings. As the pandemic passes into its third year, a substantial role of vitamin D deficiency in determining the risk from COVID-19 remains possible but unproven.

Is antenatal or early-life vitamin D associated with eczema or food allergy in childhood? A systematic review.

OBJECTIVE: To summarise the associations between antenatal or early-life blood vitamin D and the development of eczema/food allergy in childhood. DESIGN: A systematic review and meta-analyses were conducted to synthesize the published literature. Two reviewers independently performed the study selection and data extraction on Covidence. We assessed the risk of bias for observational studies by using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias tool for clinical trials. The certainty of the evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluations (GRADE). DATA SOURCES: We systematically searched PubMed and Embase from inception and April 2022. ELIGIBILITY CRITERIA: Human studies that investigated prospective associations between antenatal or early-life blood vitamin D levels, dietary intake or supplementation and childhood eczema/food allergy. RESULTS: Forty-three articles including six randomised controlled trials (RCTs) were included. Four RCTs of vitamin D supplementation during pregnancy showed no evidence of an effect on the incidence of eczema (pooled odds ratio [OR] = 0.85; 0.67-1.08, I2  = 6.7%, n = 2074). Three RCTs reported null associations between supplementation in pregnancy/infancy and food allergy. From six cohort studies, increasing cord blood vitamin D levels were associated with reduced prevalence of eczema at/close to age one (OR per 10 nmol/L increase = 0.89; 0.84-0.94, I2  = 0%, 2025 participants). We found no evidence of an association between maternal antenatal or infant vitamin D level or dietary intake and the development of food allergy or eczema in offspring. CONCLUSIONS: We found an association between higher vitamin D levels in cord blood and reduced risk of eczema in cohort studies. Further trials with maternal and infant supplementation are needed to confirm if vitamin D supplementation can effectively prevent eczema or food allergy in childhood. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, No. CRD42013005559.

Influence of the COVID-19 pandemic on the vitamin D status of children: A cross-sectional study.

Coronavirus disease 2019 (COVID-19), as well as its prevention and control measures, seriously affected people's livehood, which may have affected the body's level of vitamin D (VD). This study aimed to investigate the effect of the COVID-19 pandemic on the VD status of children in Zhengzhou, China. In this study, we included 12 272 children in 2019 (before the COVID-19 pandemic) and 16 495 children in 2020 (during the COVID-19 pandemic) to examine the changes in VD levels and deficiency rates among children before and during the COVID-19 pandemic. Total VD levels in 2020 were significantly higher than those in 2019 (26.56 [18.15, 41.40] vs. 25.98 [17.92, 40.09] ng/ml, p < 0.001). Further analysis revealed that during the COVID-19 pandemic control period in 2020, the VD levels in February, March, and April were lower than those in the same months of 2019, while the VD deficiency rates were significantly higher. Additionally, our data revealed that VD levels decreased significantly with age. Among children older than 6 years, the VD deficiency rate exceeded 50%. These results indicate that we should pay close attention to VD supplementation during the COVID-19 pandemic control period and in children older than 6 years of age.

Osteomalacic myopathy: A re-emerging scourge hiding in plain sight.

We present a cluster of patients with osteomalacic myopathy in the aftermath of the COVID-19 pandemic. We believe that the home confinement of these children may have contributed to the resurgence of this condition. This deficiency is eminently reversible.

Contribution of vitamin D3 and thiols status to the outcome of COVID-19 disease in Italian pediatric and adult patients.

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV-2), was declared a global pandemic by the World Health Organization (WHO) on March 2020, causing unprecedented disease with million deaths across the globe, mostly adults. Indeed, children accounted for only a few percent of cases. Italy was the first Western country struck by the COVID-19 epidemic. Increasing age, which is one of the principal risk factors for COVID-19 mortality, is associated with declined glutathione (GSH) levels. Over the last decade, several studies demonstrated that both vitamin D (VD) and GSH have immunomodulatory properties. To verify the association between VD, GSH and the outcome of COVID-19 disease, we conducted a multicenter retrospective study in 35 children and 128 adult patients with COVID-19. Our study demonstrated a hypovitaminosis D in COVID-19 patients, suggesting a possible role of low VD status in increasing the risk of COVID-19 infection and subsequent hospitalization. In addition, we find a thiol disturbance with a GSH depletion associated to the disease severity. In children, who fortunately survived, both VD and GSH levels at admission were higher than in adults, suggesting that lower VD and thiols levels upon admission may be a modifiable risk factor for adverse outcomes and mortality in hospitalized patients with COVID-19.

The Role of Vitamin D in Supporting Health in the COVID-19 Era.

The genomic activity of vitamin D is associated with metabolic effects, and the hormone has a strong impact on several physiological functions and, therefore, on health. Among its renowned functions, vitamin D is an immunomodulator and a molecule with an anti-inflammatory effect, and, recently, it has been much studied in relation to its response against viral infections, especially against COVID-19. This review aims to take stock of the correlation studies between vitamin D deficiency and increased risks of severe COVID-19 disease and, similarly, between vitamin D deficiency and acute respiratory distress syndrome. Based on this evidence, supplementation with vitamin D has been tested in clinical trials, and the results are discussed. Finally, this study includes a biochemical analysis on the effects of vitamin D in the body's defense mechanisms against viral infection. In particular, the antioxidant and anti-inflammatory functions are considered in relation to energy metabolism, and the potential, beneficial effect of vitamin D in COVID-19 is described, with discussion of its influence on different biochemical pathways. The proposed, broader view of vitamin D activity could support a better-integrated approach in supplementation strategies against severe COVID-19, which could be valuable in a near future of living with an infection becoming endemic.

Vitamin D status and COVID-19 prevention in a worker subgroup in Italy.

BACKGROUND: Low levels of vitamin D are widespread in the world's population and associated with sun exposure, genetics, and lifestyles. Office workers in different occupational sectors seem more vulnerable than others. Scientific evidence reports a contribution of vitamin D in resistance to infections, opening to supplementation as a preventive action against pathogens, including SARS-CoV-2. OBJECTIVE: A pilot campaign in the workplace during the coronavirus 2019 (COVID-19) pandemic was conducted based on the preliminary measurement of vitamin D amount and its integration. METHODS: A preventive action to contrast the deficiency of vitamin D was offered to a population of 700 bank employees. Vitamin D supplementation was performed between April and June 2021, on workers (n = 139) and showed 25(OH)D serum levels ≤ 30 ng/ml. Demographic, anthropometric and lifestyle information were collected by survey and changes in the serum 25(OH)D amounts were monitored. RESULTS: The adherence of the target population to the prevention campaign was 21%. 75% of the enrolled workers had low levels of vitamin D. After the intervention, serum vitamin D levels increased (1.28-fold;p = 0.0001) and 80% of the subjects reported optimal values > 30 ng/ml. Only 2.9% reported slight flu-like symptoms, but only 0.7% was confirmed as COVID-19, with respect to a ten-fold higher incidence in the general population. CONCLUSIONS: Vitamin D supplementation can be achieved by simple and noninvasive approaches and can bring along further insights into health literacy on diet and lifestyles, representing an opportunity to protect the population by the widespread state of vitamin deficiency.