Higher risk of vitamin D insufficiency/deficiency for rural than urban dwellers

Impact of the COVID-19 lockdown on the vitamin D status of people in the West of Ireland

OBJECTIVE

Identify the impact of COVID-19 lockdown restrictions on the vitamin D status of individuals in the west of Ireland.

DESIGN

Cross-sectional study.

SETTING

Adults who had wintertime serum 25(OH)D analysis completed in Galway University Hospital.

PARTICIPANTS

A total of 16,725 participants (2015-2020 (n = 13,449) and 2020-2021 (n = 3276)). Baseline demographics; sex, age, origin of the sample and the date of sample collection.

RESULTS

Median serum vitamin D and serum vitamin D3 concentrations were higher in the 5-month period from October-February 2020-2021 (61 nmol/L (± 36-85 nmol/L) and 60 nmol/L (± 34-85 nmol/L)) respectively, than for the corresponding 5-month period (October-February) in 2015-2020 (53 nmol/L (± 32-78 nmol/L) and 51 nmol/L (± 30-77 nmol/L)) respectively. These changes coincided with a decline in the prevalence of deficiency. In the 5-month period October-February 2020-2021, 19.2% of the population were vitamin D deficient (< 30 nmol/L) compared to 22.5% in the corresponding 5-month period in 2015-2020, and 38.1% were vitamin D deficient (< 50 nmol/L) in the 5-month period October-February 2020-2021 compared to 46.6% in the corresponding 5-month period in 2015-2020. Males were more likely to be deficient at both thresholds (p < 0.001). For the total cohort, at the < 30 nmol/L threshold, inpatients (25.5%) and nursing home residents (34.1%) had higher prevalence of deficiency.

CONCLUSIONS

Vitamin D levels were higher in the 5-month period of October-February 2020-2021, and this precipitated a decline in deficiency at both thresholds, indicating that lockdown coincided with enhanced vitamin D status. We postulate that it may be attributable to changes in diet and/or supplementation, or increased sun exposure, but further confirmatory studies are required.

Variation in vitamin D status in infants and children: a two-year cross-sectional study in Shanghai, China

BACKGROUND

Vitamin D deficiency (VDD) is a public health problem. The variation in vitamin D status across regions and populations remains unclear, and there is a lack of consensus regarding the screening for VDD in individuals.

METHODS

Children who visited the hospital from January 2019 to December 2020 were included in this study. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured using an enzyme-linked immunosorbent assay. The cutoffs for serum 25(OH)D concentrations to define deficiency, insufficiency, and sufficiency were < 20 ng/mL, 20-30 ng/mL, and ≥ 30 ng/mL, respectively.

RESULTS

A total of 7285 children aged 0-11 years were assessed; the mean 25(OH)D level was 31.4 ng/mL, and the median 25(OH)D level was 30.7 (interquartile range 24.4, 37.5) ng/mL. The 25(OH)D level declined with age in clinical visiting children aged 0-11 years, but maintained a consistently high level in health examination children aged 4-11 years. The percentages of 25(OH)D < 20 ng/mL and 25(OH)D < 30 ng/mL were 10.0% and 43.8%, respectively. Higher percentages of VDD were found in clinical visiting children than in health examination children within the 6-11-year group (53.3% vs. 14.7%) and winter (44.3% vs. 15.4%).

CONCLUSION

Low vitamin D status (deficiency and insufficiency) was more common in clinic-visiting children than in health examinations, especially in schoolchildren and in the winter. The study implies the positive effects of vitamin D assessments included in child health checkups to optimize vitamin D status.

Vitamin D: determinants of status, indications for testing and knowledge in a convenience sample of Irish adults

Vitamin D deficiency is common in Irish adults, though there is limited research on its determinants, knowledge of vitamin D or indications for testing. We aimed to explore the determinants of vitamin D status in adults and examine knowledge and reasons for testing. The study population comprised adults who had serum 25-hydroxyvitamin D tested by general practitioners request at a Dublin Hospital in 2020. Questionnaires detailing dietary intake, sun exposure, ethnicity, biophysical factors and vitamin D knowledge were sent to a sample stratified by age, sex and vitamin D status. In total, there were 383 participants, mean age 56·0 (sd 16·6) years. Wintertime deficiency disproportionally affected non-white v. white (60 % v. 24 %, P < 0·001). The greatest predictors of deficiency were low vitamin D intake (< 10 μg/d) (P < 0·001) and non-white ethnicity (P = 0·006), followed by sun avoidance (P = 0·022). It was also more prevalent in those with lower body exposure when outdoors. The majority (86 %) identified vitamin D as important for bone health. However, 40 % were tested for non-clinical indications and half were not aware of the recommended daily allowance (RDA). Low vitamin D intake was the most important determinant of deficiency, but ethnicity and sun exposure habits were also significant predictors. The majority had no clear indication for testing and were not aware of the RDA. Public health policies to improve knowledge and vitamin D intake, especially for those of non-white ethnicity and with reduced sun exposure, should be considered.

Vitamin D deficiency in adolescents with obesity - Altered metabolism or environmental factors?

Introduction

Introduction: obesity childhood is related to vitamin D deficiency. The aim of this study was to compare vitamin D status between adolescents with obesity living in an urban area and in a rural area. We hypothesized that environmental factors would be decisive in reducing the body content of vitamin D in patients with obesity. Methods: a cross-sectional clinical and analytical study (calcium, phosphorus, calcidiol and parathyroid hormone) was carried out in a group of 259 adolescents with obesity (BMI-SDS > 2.0), 249 adolescents with severe obesity (BMI-SDS > 3.0) and 251 healthy adolescents. The place of residence was categorized as urban or rural. Vitamin D status was defined according to the US Endocrine Society criteria. Results: vitamin D deficiency was significantly higher (p < 0.001) in severe obesity (55 %) and obesity groups (37.1 %) than in the control group (14 %). Vitamin D deficiency was more frequent in severe obesity (67.2 %) and obesity groups (51.2 %) living in urban areas than in those living in rural areas (41.5 % and 23.9 %, respectively). The patients with obesity living in urban residence did not present significant seasonal variations in vitamin D deficiency in contrast to those patients with obesity living in rural residence. Conclusions: the most probable mechanism for vitamin D deficiency in adolescents with obesity, rather than altered metabolic is the environmental factors (sedentary lifestyle and lack of adequate sunlight exposure).

Vitamin D status among infants and children in Shanghai, China: A hospital-based study

The variation in vitamin D status is still unclear. We aim to describe the vitamin D status among healthy infants and children in Shanghai (31° N latitude), one of the largest cities in China. We conducted a hospital-based, 2-year retrospective observational study and recruited children for health examination at the Tongren Hospital affiliated with Shanghai Jiao Tong University School of Medicine from January 2019 to December 2020. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using an enzyme-linked immunosorbent assay. A total of 6164 children aged 0-11 years were included. Of these, 94.4% of the serum 25(OH)D measurements at first assessment were within the range of 12-50 ng/mL. The median 25(OH)D level was 31.3 (IQR 25.6, 38.1) ng/mL, the percentages of 25(OH)D < 20 ng/mL and 25(OH)D < 30 ng/mL were 10.0% and 43.8%, respectively. Low vitamin D status (deficiency and insufficiency) differed significantly by age group (infants, toddlers, preschoolers, and schoolers) and seasonality (all p < .001), but not by gender. For the sub-group (n = 855) of children with repeated assessments, their low 25(OH)D levels increased significantly whether after about a 7-month (n = 351) or 12-month (n = 504) interval, and the increments of median 25(OH)D levels were 8.1 ng/mL and 2.1 ng/mL respectively (p < .001). This study documents the vitamin D status in Shanghai, showing that low vitamin D status is common in infants and children and suggesting that the assessment of 25(OH)D level is necessary for individuals who are at risk for deficiency or excess.

A Scoping Review of Vitamin D for Nonskeletal Health: A Framework for Evidence-Based Clinical Practice

BACKGROUND

Low serum 25-hydroxy-vitamin D [25(OH)D] levels are prevalent worldwide. Although the benefits of vitamin D supplementation have focused on skeletal disorders (eg, rickets, osteomalacia, osteoporosis), emerging evidence for nonskeletal health merits further discussion.

PURPOSE

The purpose of this review was to critically examine the vitamin D supplementation literature pertaining to nonskeletal health to help guide clinicians.

METHODS

A scoping review that included observational studies and randomized clinical trials (RCTs) was performed. Evidence from meta-analyses and individual RCTs are discussed, and controversies and future directions are considered.

FINDINGS

25(OH)D deficiency is a ubiquitous condition associated with multiple nonskeletal diseases, including cardiometabolic (heart disease, diabetes, and kidney disease), immune (HIV/AIDS and cancer), lung (from traditional chronic disorders to coronavirus disease 2019), and gut diseases. Vitamin D deficiency also affects health across the life span (children, pregnant, and elderly), mental illness, and reproduction in both men and women. In contrast, vitamin D supplementation does not necessarily improve major medical outcomes, even when low 25(OH)D levels are treated. Screening for 25(OH)D status remains an important practice, primarily for high-risk patients (eg, elderly, women with osteoporosis, people with low exposure to sunlight). It is reasonable to supplement with vitamin D to treat 25(OH)D deficiency, such that if beneficial nonskeletal health occurs, this may be considered as a coadjutant instead of the central tenet of the disease. Furthermore, optimizing dosing regimens is an important clinical consideration.

IMPLICATIONS

Although 25(OH)D deficiency is prevalent in nonskeletal diseases, there is no uniform evidence that vitamin D supplementation improves major medical outcomes, even when low 25(OH)D levels are corrected. Findings from RCTs warrant caution due to possible selection bias. Overall, vitamin D supplementation must be guided by circulating levels as a reasonable medical practice to correct 25(OH)D deficiency.

The Effect of Sunlight Exposure on Vitamin D Status in Countries of Low and High Latitudes: A Systematic Literature Review

PURPOSE OF THE REVIEW

To conduct a systematic review of studies to investigate the association between climate and vitamin D in humans.

RECENT FINDINGS

There is growing interest in the association between the environment and vitamin D, but robust methods to understand this relationship are lacking. Studies focus mainly on seasonality and latitude. Research quantifying sunlight exposure necessary for adequate vitamin D synthesis in people with darker skin color and those people living at low latitudes are scarce, as are studies in urban populations that may have limited opportunity for sunlight exposure. There are gaps regarding values and timing of exposure to UV radiation required for adequate vitamin D synthesis considering skin color, geography, climate, and local irradiation. Nature-based solutions (NbS) that can mitigate climate change will become increasingly important for preventing hypovitaminosis D. For example, tree-shaded spaces might encourage more participation in outside activities and thereby favor vitamin D synthesis by the skin.

Vitamin D Status and Mortality from SARS CoV-2: A Prospective Study of Unvaccinated Caucasian Adults

COVID-19 and a low vitamin D state share common risk factors, which might explain why vitamin D deficiency has been linked with higher COVID-19 mortality. Moreover, measures of serum vitamin D may become lower during systemic inflammatory responses, further confounding the association via reverse causality. In this prospective study (recruited over 12 months), we examined whether the association between a low vitamin D state and in-hospital mortality due to SARS-CoV-2 pneumonia in unvaccinated subjects is explained by (i) the presence of shared risk factors (e.g., obesity, advanced age) or (ii) a reduction in serum 25(OH)D due to COVID-19 (i.e., reverse causality). In this cohort of 232 (mean age = 56 years) patients (all had SARS-CoV-2 diagnosed via PCR AND required supplemental oxygen therapy), we failed to find an association between serum vitamin D and levels of CRP, or other inflammatory markers. However, the hazard ratio for mortality for subjects over 70 years of age (13.2) and for subjects with a serum 25(OH)D level less than 30 nmol·L−1 (4.6) remained significantly elevated even after adjustment for gender, obesity and the presence of diabetes mellitus. Subjects <70 years and >70 years had significantly higher mortality with a serum 25(OH)D less than 30 nmol·L−1 (11.8% and 55%), than with a serum 25(OH)D greater than 30 nmol·L−1 (2.2% and 25%). Unvaccinated Caucasian adults with a low vitamin D state have higher mortality due to SARS CoV-2 pneumonia, which is not explained by confounders and is not closely linked with elevated serum CRP.

The Burden of Cancer, Government Strategic Policies, and Challenges in Pakistan: A Comprehensive Review

Cancer is a severe condition characterized by uncontrolled cell division and increasing reported mortality and diagnostic cases. In 2040, an estimated 28.4 million cancer cases are expected to happen globally. In 2020, an estimated 19.3 million new cancer cases (18.1 million excluding non-melanoma skin cancer) had been diagnosed worldwide, with around 10.0 million cancer deaths. Breast cancer cases have increased by 2.26 million, lung cancer by 2.21 million, stomach by 1.089 million, liver by 0.96 million, and colon cancer by 1.93 million. Cancer is becoming more prevalent in Pakistan, with 19 million new cancer cases recorded in 2020. Food adulteration, gutkha, paan, and nutritional deficiencies are major cancer risk factors that interplay with cancer pathogenesis in this country. Government policies and legislation, cancer treatment challenges, and prevention must be revised seriously. This review presents the current cancer epidemiology in Pakistan to better understand cancer basis. It summarizes current cancer risk factors, causes, and the strategies and policies of the country against cancer.

Prevalence and Correlates of Vitamin D Deficiency in Children Aged Less than Two Years: A Cross-Sectional Study from Aseer Region, Southwestern Saudi Arabia

Background: Vitamin D is an essential nutrient for bone growth, mineralization, and other metabolic processes in the human body. Hence, insufficiency or deficiency of this vitamin can have long-term effects, particularly for children. Objectives: The aims of this study were to determine the prevalence of vitamin D deficiency in children up to 2 years of age and investigate the independent predictors of vitamin D deficiency. Methodology: This cross-sectional study was conducted among 484 children aged up to two years who were admitted to the hospital for the treatment of any acute condition from January to November 2021. Serum 25(OH)D was used to determine the level of vitamin D. The serum 25(OH)D was categorized into 3 groups: Sufficiency (>30 ng/mL), insufficiency (20−30 ng/mL), and the deficiency (<20 ng/mL). Results: Overall, vitamin D deficiency was observed in 70.5% of the children, of whom 45.9% had insufficient levels, and one-fourth (24.6%) showed deficiency. The children aged 2−12 months (infants) were more likely to be vitamin deficient compared to children aged 12 months and above. The children who lived in urban areas had a threefold increased risk of vitamin D deficiency (aOR = 3.0, 95% CI 1.78−5.08). The children who were exposed to sunlight for less than 3 days per week experienced a higher risk of developing vitamin D deficiency (aOR = 4.17, 95% CI 2.04−10.88). Children who had received only breast milk were more than two times more likely to experience vitamin D deficiency (aOR = 2.42, 95% CI 1.12−5.23) compared to their counterparts. Conclusion: Our study reveals a high prevalence of vitamin D deficiency among children aged up to two years. Infants, urban dwellers, only breastfed, and exposure to sunlight for less than three days per week were identified to be the independent risk factors for vitamin D deficiency. The results of this work call for enhancing awareness to ensure adequate levels of vitamin D for better health of the children in this region of Saudi Arabia.

Title: Understanding a Low Vitamin D State in the Context of COVID-19

While a low vitamin D state has been associated with an increased risk of infection by SARS-CoV-2 in addition to an increased severity of COVID-19 disease, a causal role is not yet established. Here, we review the evidence relating to i) vitamin D and its role in SARS-CoV-2 infection and COVID-19 disease ii) the vitamin D status in the Irish adult population iii) the use of supplemental vitamin D to treat a deficient status and iv) the application of the Bradford-Hill causation criteria. We conclude that reverse causality probably makes a minimal contribution to the presence of low vitamin D states in the setting of COVID-19. Applying the Bradford-Hill criteria, however, the collective literature supports a causal association between low vitamin D status, SARS-CoV-2 infection, and severe COVID-19 (respiratory failure, requirement for ventilation and mortality). A biologically plausible rationale exists for these findings, given vitamin D's role in immune regulation. The thresholds which define low, deficient, and replete vitamin D states vary according to the disease studied, underscoring the complexities for determining the goals for supplementation. All are currently unknown in the setting of COVID-19. The design of vitamin D randomised controlled trials is notoriously problematic and these trials commonly fail for a number of behavioural and methodological reasons. In Ireland, as in most other countries, low vitamin D status is common in older adults, adults in institutions, and with obesity, dark skin, low UVB exposure, diabetes and low socio-economic status. Physiological vitamin D levels for optimal immune function are considerably higher than those that can be achieved from food and sunlight exposure alone in Ireland. A window exists in which a significant number of adults could benefit from vitamin D supplementation, not least because of recent data demonstrating an association between vitamin D status and COVID-19. During the COVID pandemic, we believe that supplementation with 20-25ug (800-1000 IU)/day or more may be required for adults with apparently normal immune systems to improve immunity against SARS-CoV-2. We expect that higher monitored doses of 37.5-50 ug (1,500-2,000)/day may be needed for vulnerable groups (e.g., those with obesity, darker skin, diabetes mellitus and older adults). Such doses are within the safe daily intakes cited by international advisory agencies.

Fabrication of electrochemical immunosensor based on GCN-β-CD/Au nanocomposite for the monitoring of vitamin D deficiency

Serum 25-hydroxyvitamin D (25(OH)D) has been clinically considered as a novel biomarker for vitamin D deficiency. The current standard technologies for the detection of 25(OH)D are performed in sophisticated laboratories exhibiting the practical limitations for onsite and affordable testing. Therefore, the development of a cost-effective device for Vitamin D is extremely necessary to provide an earlier diagnosis. Herein, for the first time, we propose a novel label-free impedimetric immunosensor for the detection and quantification of 25-hydroxyvitamin D3 (25(OH)D3) biomarker in serum samples based on the Au nanoparticles functionalized GCN-β-CD nanocomposite. To fabricate the sensing probe, Ab-25(OH)D3 antibodies were covalently immobilized on GCN-β-CD@Au/GCE using carbodiimide chemistry. The surface morphology and structural properties of constructed immunosensor were confirmed by different analytical techniques. Electrochemical impedance spectroscopy technique (EIS) has been selected as the main detection method to measure the Antibody (Ab) and Antigen (Ag) interaction at the immunosensor surface because it is label-free, less destructive to the activities of the biomolecule, and highly sensitive. The as-prepared immunosensor exhibited an excellent concentration range from 0.1 ng/ml to 500 ng/ml with the lowest limit of detection of 0.01 ng/ml. Furthermore, the sensing probe was validated in serum samples and obtained results were compared with the standard CLIA technique. The results have revealed that the sensing probe could be used for clinical diagnosis of Vitamin D deficiency in the clinical laboratories.

Vitamin D Status and Bone Health in Postmenopausal Women Working in Greenhouses

Objectives

Greenhouse workers synthesize less vitamin D because ultraviolet light is blocked by the vinyl that covers the greenhouses. This study aimed to investigate the vitamin D status and bone health of postmenopausal women working in greenhouses.

Methods

This observational study enrolled women living in urban (n = 70, group 1) and rural areas (n = 91, group 2) and those working in greenhouses (n = 112, group 3). Serum levels of total and bioavailable 25-hydroxy-vitamin D [25(OH)D] and vitamin D binding protein were measured. T-scores of the lumbar spine and femur neck were measured by dual-energy X-ray absorptionetry.

Results

Heights were shorter in group 2 and group 3 than in group 1. Bioavailable 25(OH)D levels were higher and T-scores of the spine and femur were lower in both group 2 and 3 than in group 1. T-scores of the femur in group 3 were lower than those in group 2. The linear regression analysis showed that levels of bioavailable 25(OH)D significantly correlated with the spine T-scores but not with the femur T-scores. The prevalence of spinal osteoporosis was higher in both groups 2 and 3 compared to group 1. Group 3 demonstrated greater femur osteoporosis compared to groups 1 and 2.

Conclusions

Vitamin D plays an important role in spinal bone health. Moreover, working conditions are likely to play an important role in femur bone health. Therefore, appropriate working conditions and nutrition are paramount to improve bone health in postmenopausal women working in greenhouses.

Impact of vitamin D deficiency on COVID-19

Background & aims

COVID-19 has emerged as a global pandemic affecting millions of people. Vitamin D deficiency is one of the risk factors for increased susceptibility to COVID-19. This study aimed to examine the correlation between the prevalence of vitamin D deficiency and COVID-19 infection and mortality rates among the adult population in European and Asian continents.

Methods

Prevalence of vitamin D deficiency in each country was retrieved through literature searching on PubMed® database for the last ten years. As of December, 31^st 2020, COVID-19 infections and mortalities per million population were extracted from the ‘real time’ statistics of the Worldometer website. The association between both vitamin D deficiency and COVID-19 infections and mortalities were explored.

Results

Forty seven countries were included in the analysis. The prevalence of vitamin D deficiency ranged from 6.9 to 81.8% in European countries and 2.0–87.5% in Asian countries. Significantly positive correlations were observed for both COVID-19 infection (r = 0.76; p < 0.001) and mortality rates (r = 0.75; p < 0.001) in the Asian continent. The correlation values for the infections and mortality rates in the European continent were (r = 0.37; p = 0.08) and (r = 0.43; p = 0.04) respectively. When both the continents were combined, the correlation results for both infection (r = 0.42; p = 0.003) and mortality (r = 0.35; p = 0.016) rates with vitamin D deficiency values remained significant.

Conclusion

Prevalence of vitamin D deficiency was significantly associated with the mortality rate of COVID-19 in Europe and Asia. The association between the infection rate and prevalence of vitamin D deficiency was significant for Asia only. Both the associations were significant when the two continents were combined in the analysis. Therefore we suggest that vitamin D supplementation could play a key role in the prevention and/or treatment of the COVID-19 patients.

Vitamin D Status of Adults in the Community, in Outpatient Clinics, in Hospital, and in Nursing Homes in the West of Ireland

BACKGROUND

Approximately 1 billion people worldwide have Vitamin D deficiency. The aim of this study was to compare Vitamin D status and serum 25-hydroxyvitamin D (25(OH)D) concentrations among adults sampled in the community, in outpatient clinics, as hospital inpatients and in nursing homes in the West of Ireland. The secondary aim was to determine the associations between length of hospital stay (inpatients) at the time of serum 25(OH)D sampling and Vitamin D status.

METHODS

A cross-sectional study was carried out. Patients who had serum 25(OH)D analysis carried out in Galway University Hospitals (January 2011-December 2015) were identified following interrogation of the electronic laboratory data system. Baseline demographics, location, and date of sample collection were recorded. Vitamin D deficiency was defined as a serum 25(OH)D concentration <25 nmol/L.

RESULTS

In total, 24,302 patient samples were eligible for inclusion: community 15,319; outpatient clinics 6,371; inpatients 2,339; and nursing home residents 273. Vitamin D deficiency was more common in nursing home residents than inpatients, or those sampled in outpatient clinics or in the community (42% vs 37% vs 17% vs 13%; p < .001). Inpatients sampled further into their hospital stay (≥3 days) had greater Vitamin D deficiency than inpatients sampled on 0-2 days (p = .007). Season (p < .001), sex (p < .001), and age (p < .001) were associated with 25(OH)D concentrations. Vitamin D deficiency was more common in Winter/Spring, in males, and in those aged ≥80 years.

CONCLUSIONS

Nursing home residents and inpatients are at the highest risk for Vitamin D deficiency. Season, sex, age, and day of hospital stay on which serum 25(OH)D concentrations were sampled were associated with Vitamin D status.

Clinical Significance of Analysis of Vitamin D Status in Various Diseases

Vitamin D plays a role not only in the proper functioning of the skeletal system and the calcium-phosphate equilibrium, but also in the immune system, the cardiovascular system and the growth and division of cells. Although numerous studies have reported on the analysis of vitamin D status in various groups of patients, the clinical significance of measurements of vitamin D forms and metabolites remains ambiguous. This article reviews the reports analyzing the status of vitamin D in various chronic states. Particular attention is given to factors affecting measurement of vitamin D forms and metabolites. Relevant papers published during recent years were identified by an extensive PubMed search using appropriate keywords. Measurement of vitamin D status proved to be a useful tool in diagnosis and progression of metabolic syndrome, neurological disorders and cancer. High performance liquid chromatography coupled with tandem mass spectrometry has become the preferred method for analyzing the various forms and metabolites of vitamin D in biological fluids. Factors influencing vitamin D concentration, including socio-demographic and biochemical factors as well as the genetic polymorphism of the vitamin D receptor, along with vitamin D transporters and enzymes participating in vitamin D metabolism should be considered as potential confounders of the interpretation of plasma total 25(OH)D concentrations.

Geomapping Vitamin D Status in a Large City and Surrounding Population-Exploring the Impact of Location and Demographics

Vitamin D status was assessed in a large urban area to compare differences in deficiency and to geomap the results. In total, 36,466 participants from 28 geographical areas were identified in this cross-sectional, retrospective analysis of general practitioner (GP)-requested 25(OH)D tests at St James's Hospital, Dublin between 2014 and 2018. The population were community-dwelling adults, median age 50.7 (18-109 years) with 15% of participants deficient (<30 nmol/L), rising to 23% in the winter. Deficiency was greatest in younger (18-39 years) and oldest (80+ years) adults, and in males versus females (18% vs. 11%, p < 0.001). Season was the biggest predictor of deficiency (OR 4.44, winter versus summer, p < 0.001), followed by location (west Dublin OR 2.17, north Dublin 1.54, south Dublin 1.42 versus rest of Ireland, p < 0.001) where several urban areas with an increased prevalence of deficiency were identified. There was no improvement in 25(OH)D over the 5-year period despite increased levels of testing. One in four adults were vitamin D deficient in the winter, with significant variations across locations and demographics. Overall this study identifies key groups at risk of 25(OH)D deficiency and insufficiency, thus providing important public health information for the targeting of interventions to optimise 25(OH)D. Mandatory fortification may be necessary to address this widespread inadequacy.

Biallelic CYP24A1 variants presenting during pregnancy: clinical and biochemical phenotypes

INTRODUCTION

Inactivating mutations in CYP24A1, encoding vitamin D-24-hydroxylase, can lead to an accumulation of active vitamin D metabolites and consequent hypercalcaemia. Patient (infantile and adult) presentation is varied and includes mild-severe hypercalcaemia, hypercalciuria, nephrocalcinosis and nephrolithiasis. This study aimed to characterize the clinical and biochemical phenotypes of a family with two CYP24A1 missense variants.

METHODS

The proband and seven family members underwent detailed clinical and biochemical evaluation. Laboratory measurements included serum calcium, intact parathyroid hormone (iPTH), vitamin D metabolites and urine calcium and creatinine.

RESULTS

The proband presented during the second trimester of a planned pregnancy with flu-like symptoms. Laboratory tests showed elevated adjusted calcium of 3.27 (upper reference limit (URL: 2.30) mmol/L), suppressed iPTH (<6 ng/L), elevated 25(OH)D (264 (URL: 55) nmol/L) and elevated 1,25(OH)D (293 (URL: <280) pmol/L). Ionized calcium was 1.55 (URL: 1.28) mmol/L. Sanger sequencing revealed two heterozygous missense variants in the CYP24A1: p.(Arg439Cys), R439C and p.(Trp275Arg), W275R. The proband's brother and sister had the same genotype. The brother had intermittent hypercalcaemia and hypervitaminosis D. Only the sister had a history of nephrolithiasis. The proband's daughter and two nephews were heterozygous for the R439C variant. The proband and her brother frequently had elevated 25(OH)D:24,25(OH)2D ratios (>50) during follow-up.

CONCLUSIONS

W275R is a new pathogenic CYP24A1 mutation in compound heterozygotic form with R439C in this family.

COVID-19: the older adult and the importance of vitamin D sufficiency

In December 2019, in Wuhan, China, the novel coronavirus ‘severe acute respiratory syndrome 2’ (SARS-CoV-2) was discovered as the cause of a pneumonia-like illness and subsequently named coronavirus disease 2019 (COVID-19). COVID-19 spread and is now a global pandemic. With few exceptions, countries in the Northern hemisphere have higher mortality rates from COVID-19. This may be due to an increased prevalence of older people in Northern Europe at higher risk of having cardio-pulmonary and metabolic comorbidities as well as hypovitaminosis D. With increasing age, immunosenescence and ‘inflammaging’ lead to impaired and maladaptive immune responses to SARS-CoV-2 infections, contributing to the enhanced prevalence of severe COVID-19 in older patients. The association of ageing with increased vitamin D deficiency, which is associated with cardiovascular risk factors and disease and worse prognosis in COVID-19 infection, is discussed. Considerable experimental evidence demonstrates the immuno-modulatory properties of vitamin D, in particular, its role in regulating and suppressing the inflammatory cytokine response to viral respiratory infections links the importance of vitamin D sufficiency as a potential protective factor in COVID-19. There is an urgent need for prospective randomised studies to examine whether hypovitaminosis D correlates with severity of COVID-19 disease and the actual benefit of repletion. Moreover, given what has been described as a ‘pandemic of vitamin D deficiency’, especially in Europe, and in the context of the SARS-CoV-2 contagion, the authors support the call for public health doctors and physicians, with support from Governments, to prioritise and strengthen recommendations on vitamin D intake and supplementation.