Vitamin D Status in Adolescents during COVID-19 Pandemic: A Cross-Sectional Comparative Study

Changes in vitamin D status among adults from the COVID-19 pandemic to post-pandemic normality

Introduction

The COVID-19 pandemic has prompted widespread lockdown measures globally, significantly impacting daily activities and outdoor exposure. This study investigates the effect of the pandemic on vitamin D levels and the prevalence of vitamin D deficiency in the adult population, with a focus on gender-specific differences.

Methods

A total of 1525 adults from Henan Provincial People's Hospital were included. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using the Elecsys® Vitamin D total kit on the Roche Cobas® 8000 analyzer. The Clinical Application Consensus on Vitamin D and Its Analogs defined deficiency as 25(OH)D levels below 20 ng/ml. Statistical analysis was performed using SPSS 23.0 and GraphPad Prism 8 software.

Results

The overall 25(OH)D levels increased from 18.14 ng/ml [IQR: 13.78, 23.68] in 2022 to 19.15 ng/ml [IQR: 14.88, 25.01] in 2023 (p=0.004). Males exhibited significant improvement in 25(OH)D levels from 18.01 ng/ml [IQR: 14.10, 23.53] in 2022 to 20.49 ng/ml [IQR: 16.11, 26.01] in 2023 (p<0.001). The prevalence of vitamin D deficiency decreased from 62% in 2022 to 54.9% in 2023 (p=0.009), with a notable reduction in males (64.1% in 2022 to 47.2% in 2023). Among 168 individuals tested in both years, 25(OH)D levels increased from 20.73 ± 9.37 ng/ml in 2022 to 22.28 ± 8.59 ng/ml in 2023 (p=0.012), and the deficiency rate decreased from 58.3% in 2022 to 47.0% in 2023 (p=0.038). The 40-49 age group showed significant improvement in 25(OH)D levels from 16.10 ng/ml [IQR: 12.41, 21.18] in 2022 to 18.28 ng/ml [IQR: 13.91, 23.86] in 2023 (p=0.005), with a reduction in deficiency rate from 72.8% to 59.9% (p=0.02). Furthermore, in February, March, and April, 2022, 25(OH)D levels were significantly lower compared to 2023 (p<0.001, p=0.002, p<0.001, respectively), accompanied by a higher prevalence of vitamin D deficiency (p<0.001, p=0.015, p<0.001, respectively).

Discussion

This study demonstrates that the COVID-19 pandemic significantly impacted vitamin D levels, leading to an increased prevalence of deficiency, particularly among males. These findings highlight the critical importance of maintaining sufficient outdoor activities to ensure adequate vitamin D levels. The data underscore the need for public health strategies to address potential deficiencies during prolonged periods of limited outdoor exposure.

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.

Vitamin D Deficiency Prevalence in Hospitalized Patients with COVID-19 Significantly Decreased during the Pandemic in Slovakia from 2020 to 2022 Which Was Associated with Decreasing Mortality

The coronavirus disease 2019 (COVID-19) pandemic has led to changes in lifestyle, which could influence vitamin D status on a population level. The purpose of our study was to compare 25-hydroxyvitamin D (25[OH]D) levels in patients hospitalized because of severe COVID-19 during two waves of the pandemic (2020/21 vs. 2021/22). A total of 101 patients from the 2021/22 wave were compared with 101 sex- and age-matched subjects from the 2020/21 wave. Patients from both groups were hospitalized during the winter season from 1 December to 28 February. Men and women were analyzed together and separately. The mean 25(OH)D concentration increased from 17.8 ± 9.7 ng/mL to 25.2 ± 12.6 ng/mL between waves. The prevalence of vitamin D deficiency (<20 ng/mL) decreased from 82% to 54%. The prevalence of adequate serum 25(OH)D concentration (>30 ng/mL) increased from 10% to 34% (p < 0.0001). The proportion of patients with a history of vitamin D supplementation increased from 18% to 44% (p < 0.0001). Low serum 25(OH)D concentration was independently associated with mortality after adjusting for age and sex for the whole cohort of patients (p < 0.0001). The prevalence of inadequate vitamin D status in hospitalized patients with COVID-19 in Slovakia decreased significantly, probably due to a higher rate of vitamin D supplementation during the COVID-19 pandemic.

Vitamin D Supply of Multivitamins Commercialized Online by Amazon in Western and Southern Europe: A Labeling Analysis

Multivitamins are commonly used by the general population, often without medical prescription. The purpose of this report is to inform on the daily vitamin D supply provided by multivitamins containing vitamin D that are commercialized online by Amazon in Western and Southern Europe. We surveyed multivitamins aimed at adults using the following marketplaces: amazon.es®, amazon.de®, amazon.it®, and amazon.fr®. We identified 199 vitamin D3-containing multivitamins sold by Amazon marketplaces: 77 from amazon.es®, 73 from amazon.de®, 33 from amazon.it®, and 16 from amazon.fr®. No multivitamin contained vitamin D2. The daily vitamin D3 supply ranged from 16 to 2000 IU: it was less than 400 IU daily in 108 (54%), 400−800 IU daily in 53 (27%), and more than 800 IU daily in the remaining 38 (19%) products. The vitamin D3 supply of products sold by amazon.it® was on average higher (p < 0.05) than that of products sold by amazon.de®, amazon.fr®, and amazon.es®. In conclusion, the vitamin D supply of multivitamins sold by Amazon may be insufficient, marginally sufficient, or adequate for subjects at high risk of hypovitaminosis D such as subjects 65 years or more of age, pregnant (or lactating) women, or patients on drug treatment or with an underlying disease, where a vitamin D supplementation is advocated.

The Role of Some Vitamins in Respiratory-related Viral Infections: A Narrative Review

This study aimed to find out the effect of vitamins on respiratory-related viral infections, including coronavirus disease 2019 (COVID-19), through the literature reviews. From January 2000 to June 2021, the studies (cohort studies, cross-sectional studies, case-control studies, randomized control trials) related to vitamins (vitamin A, D, E, C, B6, folate, and B12) and COVID-19/severe acute respiratory syndrome/Middle East respiratory syndrome/cold/influenza were selected from the PubMed, Embase, and Cochrane libraries and analyzed. The relationship between vitamins and virus-related respiratory diseases was identified. Through the review, 39 studies were selected on vitamin D, one study on vitamin E, 11 studies on vitamin C, and 3 studies on folate. Regarding COVID-19, 18 studies on vitamin D, 4 studies on vitamin C, and 2 studies on folate showed significant effects of the intake of these nutrients in preventing COVID-19. Regarding colds and influenza, 3 studies on vitamin D, 1 study on vitamin E, 3 studies on vitamin C, and 1 study on folate demonstrated that the intake of these nutrients significantly prevents these diseases. Therefore, this review suggested the intake of vitamins D, E, C, and folate is important for preventing respiratory diseases related to viruses, such as COVID-19, colds, and influenza. The relationship between these nutrients and virus-related respiratory diseases should be continuously monitored in the future.

Changes in Vitamin D Status in Korean Adults during the COVID-19 Pandemic

The aim of this study was to investigate changes in 25(OH)D (25-hydroxyvitamin D) levels and in the vitamin D status of Korean adults before and during the coronavirus disease (COVID-19) pandemic. This study compared serum 25(OH)D levels before and after the pandemic in 1483 adults aged 19 years and older who were screened at a university hospital. Subjects were selected only from participants tested in the same season before and after the pandemic. The pre-COVID-19 testing period was from 1 March 2018 to 31 November 2019; the testing period in the COVID-19 era was from 1 June 2020 to 31 November 2021. The mean 25(OH)D level for all participants was 21.4 ± 10.2 ng/mL prior to the outbreak of COVID-19, which increased to 23.6 ± 11.8 ng/mL during the COVID-19 lockdown period (p < 0.001). The increase was particularly dramatic in elderly females (28.8 ± 12.3 ng/mL to 37.7 ± 18.6 ng/mL, p = 0.008). The prevalence of vitamin D deficiency decreased in both males (48.4% to 44.5%, p = 0.005) and females (57.0% to 46.0%, p < 0.001). In conclusion, 25(OH)D levels in Korean adults increased during the COVID-19 era, and the prevalence of vitamin D deficiency decreased accordingly.

How Vitamin D Levels of Children Changed During COVID-19 Pandemic: A Comparison of Pre-pandemic and Pandemic Periods

OBJECTIVE

The synthesis of vitamin D is related to sun exposure, thus the restrictions during the Coronavirus disease-2019 (COVID-19) pandemic may have affected the levels of vitamin D in all age groups. The aim of this study was to evaluate vitamin D levels of healthy children and adolescents during the first year of the pandemic.

METHODS

The study group included healthy children and adolescents who were admitted for general check-ups and evaluated with 25(OH)D levels. Then, it was divided into two groups: Group 1 “pre-pandemic”, and Group 2 “pandemic”. Vitamin D levels were recorded from the hospital database and were compared according to age groups, gender, and the season, retrospectively.

RESULTS

The study group [mean age=90.29±59.45 median age=79 interquartile range (IQR): 102 months, male/female: 1409/1624] included 3033 children and adolescents (Group 1/Group 2 n=1864/1169). Although the mean 25(OH)D levels among preschool children did not differ between groups, the vitamin D levels of school-aged children and adolescents were significantly lower in the pandemic period than in the pre-pandemic period [Group 1 median=16.50 (IQR: 10.5) vs Group 2 median=15.9 (IQR: 11.3) in 6-12 age group (p=0.026); Group 1 median=13.30 (IQR: 10.2) vs Group 2 median=11.20 (IQR: 9.7) in 12-18 age group (p=0.003)]. Moreover, the 25(OH)D levels of adolescents showed seasonal variance with lower levels in winter, and unexpectedly, in summer.

CONCLUSION

Pandemic-related restrictions have caused significant decreases in vitamin D levels of school-aged children and adolescents. We suggest that children and adolescents should be given vitamin D supplementation in order to maintain sufficient levels of vitamin D during the pandemic.

Do Diet and Dietary Supplements Mitigate Clinical Outcomes in COVID-19?

The coronavirus disease 2019 (COVID-19) has caused a pandemic and upheaval that health authorities and citizens around the globe are still grappling with to this day. While public health measures, vaccine development, and new therapeutics have made great strides in understanding and managing the pandemic, there has been an increasing focus on the potential roles of diet and supplementation in disease prevention and adjuvant treatment. In the literature, the impact of nutrition on other respiratory illnesses, including the common cold, pneumonia, and influenza, has been widely demonstrated in both animal and human models. However, there is much less research on the impact related to COVID-19. The present study discusses the potential uses of diets, vitamins, and supplements, including the Mediterranean diet, glutathione, zinc, and traditional Chinese medicine, in the prevention of infection and severe illness. The evidence demonstrating the efficacy of diet supplementation on infection risk, disease duration, severity, and recovery is mixed and inconsistent. More clinical trials are necessary in order to clearly demonstrate the contribution of nutrition and to guide potential therapeutic protocols.

Efficacy and safety of vitamin D supplementation in hospitalized COVID-19 pediatric patients: A randomized controlled trial

BACKGROUND

Some studies suggested that adequate levels of vitamin D (VD) decrease the risk of severe COVID-19. Information about the effectiveness of VD supplementation in children is scarce.

OBJECTIVE

To assess the efficacy and safety of VD supplementation compared to the standard of care in hospitalized children with COVID-19.

PATIENTS AND METHODS

An open-label randomized controlled single-blind clinical trial was carried out. We included patients from 1 month to 17 years, with moderate COVID-19, who required hospitalization and supplemental oxygen. They were randomized into two groups: the VD group, which received doses of 1,000 (children < 1 year) or 2,000 IU/day (from 1 to 17 years) and the group without VD (control). The outcome variables were the progression of oxygen requirement, the development of complications, and death.

STATISTICAL ANALYSIS

For comparison between groups, we used the chi-squared test or Fisher's exact test and the Mann-Whitney U test. Absolute risk reduction (ARR) and the number needed to treat (NNT) were calculated. p ≤ 0.05 was considered statistically significant.

RESULTS

From 24 March 2020 to 31 March 2021, 87 patients were eligible to participate in the trial; 45 patients were randomized: 20 to the VD group and 25 to the control group. There was no difference in general characteristics at baseline, including serum VD levels (median 13.8 ng/ml in the VD group and 11.4 ng/ml in the control group).

OUTCOMES

2/20 (10%) in the VD group vs. 9/25 (36%) in the control group progressed to a superior ventilation modality (p = 0.10); one patient in the VD group died (5%) compared to 6 (24%) patients in the control group (p = 0.23). ARR was 26% (95% CI 8.8 to 60.2%) and NNT was 3 (2 to 11) for progression and ARR was 19% (95% CI -3.9 to 42.8%) and NNT was 6 (2 to 26) for death. None of the patients receiving VD had adverse effects. The trial was stopped for ethical reasons; since after receiving the results of the basal VD values, none of the patients had normal levels.

CONCLUSION

In this trial, VD supplementation in pediatric patients seems to decrease the risk of COVID-19 progression and death. More studies are needed to confirm these findings.

CLINICAL TRIAL REGISTRATION

This protocol was registered on ClinicalTrials.gov with the registration number NCT04502667.

Differences in the Concentration of Vitamin D Metabolites in Plasma Due to the Low-Carbohydrate-High-Fat Diet and the Eastern European Diet-A Pilot Study

Vitamin D deficiency is a global problem with many health consequences, and it is currently recommended to supplement vitamin D. Change of diet should also be considered to ensure adequate vitamin D in the human body. The aim of this study was to assess the concentration of vitamin D metabolites in two different groups: one group on the low-carbohydrate-high-fat (LCHF) diet and the other group on the Eastern European (EE) diet. In the first stage, 817 participants declaring traditional EE diet or LCHF diet were investigated. Nutrition (self-reported 3-day estimated food record) and basic anthropometric parameters were assessed. After extra screening, 67 participants on the EE diet and 41 on the LCHF diet were qualified for the second stage. Plasma 25-hydroxycholecalciferol (25(OH)D₃) and (25(OH)D₂) concentration was measured by the validated HPLC—MS/MS method. Plasma 25(OH)D₃ concentration was significantly higher in the group on the LCHF diet (34.9 ± 15.9 ng/mL) than in the group on the EE diet (22.6 ± 12.1 ng/mL). No statistical differences were observed in plasma 25(OH)D₂ concentration between the study groups (p > 0.05). Women had a higher plasma 25(OH)D₂ concentration than men regardless of diet type. The LCHF diet had a positive influence on plasma vitamin D concentration. However, long-term use of the LCHF diet remains contentious due to the high risk of cardiovascular disease. This study confirmed that the type of diet influences the concentration of vitamin D metabolites in the plasma.