Lack of Seasonal Variations in Vitamin D Concentrations among Hospitalized Elderly Patients

The Global Prevalence of Vitamin D Deficiency in the Elderly: A Meta-analysis

Background

Vitamin D deficiency is widely prevalent among the elderly, posing significant health risks. This study aims to determine the global prevalence of vitamin D deficiency in the elderly.

Methods

A systematic review and meta-analysis was conducted, examining databases including Scientific Information Database (SID), Medline (PubMed), ScienceDirect, Scopus, Embase, and Google Scholar until January 2023. The publication bias of the studies was assessed using the I2 test of heterogeneity and the Egger test.

Results

The prevalence of vitamin D deficiency, defined as levels below 20 ng or 50 nmol was found to be 59.7% (95% CI 45.9-72.1). Furthermore, a review of six studies involving 6748 elderly individuals showed a prevalence of 27.5% (95% CI 21.8-34.1) for deficiency defined between 20 and 30 ng or 50-75 nmol. Additionally, a meta-analysis of seven studies with a sample size of 6918 elderly individuals reported a prevalence of 16% (95% CI 10.2-24.1) for deficiency defined above 30 nmol or 75 nmol.

Conclusion

The results of the present study reveal that the prevalence of vitamin D deficiency among the elderly is high and requires the attention of health policymakers at the World Health Organization to prioritize extensive information dissemination and screening to mitigate the adverse effects on their quality of life.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-023-01089-w.

Low serum vitamin D in North Indian multi-drug resistant pulmonary tuberculosis patients: the role of diet and sunlight

Background: Tuberculosis (TB) and malnutrition are major global health problems, with multidrug-resistant (MDR) TB complicating international efforts. The role of vitamin D in susceptibility to and as an adjunctive treatment for TB is being studied extensively, although no study has included MDR-TB patients in context to dietary profile with vitamin D levels and sunlight exposure.Objective: This study aimed to estimate vitamin D serum levels and examine their association with dietary intake of vitamin D and sun exposure in patients with MDR-TB.Methods: North Indian participants were enrolled in three groups: MDR-TB, drug-susceptible pulmonary TB (DS-PTB), and healthy controls. All consenting participants underwent the estimation of macro- and micronutrient intake and sunlight exposure using structured questionnaires. Serum biochemistry, including 25-hydroxyvitamin D and calcium levels, was measured, and the correlation between variables was determined.Results: 747 participants were enrolled. Significant differences among the three groups were found in mean serum 25-hydroxyvitamin D levels, body mass index, macronutrient intake, dietary vitamin D and calcium content, and sun exposure index (SEI). All except sun exposure (SEI was highest in DS-PTB patients) were found to follow the trend: MDR-TB < DS-PTB < healthy controls. The mean serum vitamin D levels of all groups were deficient and correlated positively with dietary intake and SEI.Conclusion: In this study's we found significant association of serum vitamin D concentrations, dietary intake and sunlight exposure in MDR-TB, DS-PTB patients and healthy controls. Dietary intake may be more important than sun exposure in determining serum levels. However, the significance of this finding is uncertain. Further studies are required to confirm the association, direction, and potential for vitamin D supplementation to treat or prevent MDR-TB infection.

Could vitamin D concentration be a marker of a long hospital stay in older adults patients?

Background and aims

Vitamin D plays a pleiotropic role in the human body. Some studies have suggested that hypovitaminosis D may serve as a marker of comorbidity severity and length of hospital stay. Hospitalized older adults patients with a higher comorbidity burden tend to have lower vitamin D status, which negatively impacts the length of their hospital stay. Vitamin D deficiency has been identified as a significant risk factor for a prolonged hospital stay. This study aimed to investigate the link between vitamin D status and prolonged hospital stays, focusing on geriatric patients, and to assess the variation in hospitalization duration among geriatric patients with different vitamin D statuses.

Methods

The study sample comprised of 422 patients aged over 60 years admitted to the geriatric department. Blood samples were collected in the morning on the day of admission. According to the diagnostic threshold defining serum 25(OH)D concentration approved for Central Europe, patients were divided into two groups (deficiency group and suboptimal group). Patients were divided into two groups based on hospitalization duration: the first, "shorter hospitalization," included stays up to 11 days, whereas the second, "longer hospitalization," encompassed stays of 12 days and above.

Results

In total, 242 Caucasian patients, primarily women (172 women and 70 men), were recruited in the study. Patients with vitamin D deficiency had extended hospital stays compared with those with vitamin D levels below 49.92 nmol/L: 10.0 (8.00-13.00) days vs. 9.00 (8.00-11.00) days, P = 0.044. Hospitalization length (in days) had a negative correlation with vitamin D blood status (nmol/L) (P = 0.0005; R = -0.2243). ROC analysis indicated that patients with vitamin D levels below 31.2 nmol/L had a 47% higher chance of extended hospitalization, whereas those with levels above 31.2 nmol/L had a 77% higher chance of avoiding it. A significant majority of patients with suboptimal 25(OH)D levels experienced shorter hospital stays (≤11 days) than those with vitamin D deficiency (64.6%), P = 0.045.

Conclusion

The study findings indicate that lower serum levels of 25(OH)D in hospitalized patients within the geriatric department are linked to extended hospital stays. Vitamin D holds potential as a predictor of hospitalization duration in geriatric patients. Nonetheless, further research is imperative to account for additional factors affecting health status and hospitalization duration in older adults individuals.

Population-wide analysis of hospital laboratory tests to assess seasonal variation and temporal reference interval modification

We identified mortality-, age-, and sex-associated differences in relation to reference intervals (RIs) for laboratory tests in population-wide data from nearly 2 million hospital patients in Denmark and comprising more than 300 million measurements. A low-parameter mathematical wave-based modification method was developed to adjust for dietary and environment influences during the year. The resulting mathematical fit allowed for improved association rates between re-classified abnormal laboratory tests, patient diagnoses, and mortality. The study highlights the need for seasonally modified RIs and presents an approach that has the potential to reduce over- and underdiagnosis, affecting both physician-patient interactions and electronic health record research as a whole.

Vitamin D, Cellular Senescence and Chronic Kidney Diseases: What Is Missing in the Equation?

As life expectancy increases in many countries, the prevalence of age-related diseases also rises. Among these conditions, chronic kidney disease is predicted to become the second cause of death in some countries before the end of the century. An important problem with kidney diseases is the lack of biomarkers to detect early damage or to predict the progression to renal failure. In addition, current treatments only retard kidney disease progression, and better tools are needed. Preclinical research has shown the involvement of the activation of cellular senescence-related mechanisms in natural aging and kidney injury. Intensive research is searching for novel treatments for kidney diseases as well as for anti-aging therapies. In this sense, many experimental shreds of evidence support that treatment with vitamin D or its analogs can exert pleiotropic protective effects in kidney injury. Moreover, vitamin D deficiency has been described in patients with kidney diseases. Here, we review recent evidence about the relationship between vitamin D and kidney diseases, explaining the underlying mechanisms of the effect of vitamin D actions, with particular attention to the modulation of cellular senescence mechanisms.

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.

The Interplay of Vitamin D Deficiency and Cellular Senescence in The Pathogenesis of Obesity-Related Co-Morbidities

This scoping review aims to clarify the interplay between obesity, vitamin D deficiency, cellular senescence, and obesity-related metabolic consequences, mainly subclinical atherosclerosis, and non-alcoholic fatty liver disease (NAFLD). Obesity is a significant global health problem that involves cellular, environmental, behavioral, and genetic elements. The fundamental cause of obesity throughout all life stages is an energy imbalance, and its consequences are countless and, foremost, very common. Obesity has been comprehensively studied in the literature given its association with low serum vitamin D, with many proposed mechanisms linking the two conditions. Moreover, markers of exaggerated cellular senescence have been proven to accumulate in obese individuals. Subclinical atherosclerosis initiates an early stage that ends in serious cardiac events, and obesity, low vitamin D, and senescent cells largely contribute to its associated chronic low-grade inflammation. Furthermore, NAFLD signifies the hepatic manifestation of metabolic syndrome, and studies have highlighted the important role of obesity, vitamin D deficiency, and cellular senescence in its development. Therefore, we outlined the most important mechanisms tying these conditions to one another.

The Impact of Vitamin D on Skin Aging

The active metabolites of vitamin D₃ (D₃) and lumisterol (L₃) exert a variety of antiaging and photoprotective effects on the skin. These are achieved through immunomodulation and include anti-inflammatory actions, regulation of keratinocytes proliferation, and differentiation programs to build the epidermal barrier necessary for maintaining skin homeostasis. In addition, they induce antioxidative responses, inhibit DNA damage and induce DNA repair mechanisms to attenuate premature skin aging and cancerogenesis. The mechanism of action would involve interaction with multiple nuclear receptors including VDR, AhR, LXR, reverse agonism on RORα and -γ, and nongenomic actions through 1,25D₃-MARRS receptor and interaction with the nongenomic binding site of the VDR. Therefore, active forms of vitamin D₃ including its canonical (1,25(OH)₂D₃) and noncanonical (CYP11A1-intitated) D₃ derivatives as well as L₃ derivatives are promising agents for the prevention, attenuation, or treatment of premature skin aging. They could be administrated orally and/or topically. Other forms of parenteral application of vitamin D₃ precursor should be considered to avoid its predominant metabolism to 25(OH)D₃ that is not recognized by CYP11A1 enzyme. The efficacy of topically applied vitamin D₃ and L₃ derivatives needs further clinical evaluation in future trials.

Power determination in vitamin D randomised control trials and characterising factors affecting it through a novel simulation-based tool

Thousands of observational studies have linked vitamin D deficiency with numerous diseases, but randomised controlled trials (RCTs) often fail to show benefit of supplementation. Population characteristics and trial design have long been suspected to undermine power but were not systematically investigated. We propose a flexible generative model to characterise benefit of vitamin D supplementation at the individual level, and use this to quantify power in RCTs. The model can account for seasonality and population heterogeneity. In a simulated 1-year trial with 1000 participants per arm and assuming a 25-hydroxyvitamin D (25OHD) increase of 20 nmol/L due to the intervention, with baseline 25OHD in the population of 15, 35, 50, 60 and 75 nmol/L, the power to detect intervention effect was 77%, 99%, 95%, 68% and 19%, respectively. The number of participants required per arm to achieve 80% power according to baseline 25OHD of 15–60 nmol/L was 1200, 400, 600 and 1400, respectively. As expected, larger increases in 25OHD due to supplementation improved power in certain scenarios. For a population baseline of 50 nmol/L, with 1500 participants in each arm, there was 100% power to detect a 20 nmol/L 25OHD increase while it was 76% for a 10 nmol/L increase. Population characteristics and trial design, including temporal considerations, have a dramatic impact on power and required sample size in vitamin D RCTs.