Vitamin D and Sun Exposure: A Community Survey in Australia

The impact of vitamin D supplementation on glycemic control and lipid metabolism in polycystic ovary syndrome: a systematic review of randomized controlled trials

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition affecting both metabolic and reproductive health in women. The impact of vitamin D on metabolic regulation has attracted growing interest. The purpose of this study is to investigate the impact of vitamin D supplementation on key metabolic parameters-namely blood glucose, insulin, and lipid levels-in individuals with PCOS.

METHODS

A systematic review was conducted to identify relevant studies in PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov. The search focused on randomized controlled trials (RCTs) evaluating the impact of vitamin D supplementation in patients with PCOS. Meta-analysis was performed using RevMan 5.3 software, and study quality was evaluated with the Cochrane Risk of Bias Tool. In addition, outcome-related evidence was graded using the GRADE system, and TSA was performed to determine if the number of participants met the required threshold.

RESULTS

A total of 691 individuals with PCOS from 13 RCTs were evaluated. The meta-analysis indicated that the supplementation of vitamin D led to a notable reduction in the subsequent metabolic parameters: fasting blood glucose[MD=-2.91 mg/dL, 95% CI (-4.78, -1.04) mg/dL, P = 0.002], insulin levels[MD=-1.98 µIU/mL, 95% CI (-3.32, -0.64) µIU/mL, P = 0.004], triglycerides[MD=-11.01 mg/dL, 95% CI (-16.42, -5.61) mg/dL, P < 0.0001], total cholesterol [MD=-11.69 mg/dL, 95% CI (-15.56, -7.82) mg/dL, P < 0.00001], very low-density lipoprotein cholesterol (VLDL-cholesterol) [MD=-2.64 mg/dL, 95% CI (-4.50, -0.79) mg/dL, P = 0.005], and low-density lipoprotein cholesterol (LDL-cholesterol) [MD=-5.85 mg/dL, 95% CI (-10.28, -1.42) mg/dL, P = 0.010]. Nevertheless, the supplementation of vitamin D did not exert a significant impact on high - density lipoprotein cholesterol (HDL - cholesterol) [MD=-0.21 mg/dL, 95% CI (-0.81, 1.22) mg/dL, P = 0.69]. Begg's and Egger's tests suggested a minimal probability of publication bias, and the TSA confirmed that the optimal sample size for major outcomes had been reached, supporting the robustness of the meta-analysis results.

CONCLUSION

Vitamin D supplementation shows significant benefits in improving metabolic parameters in PCOS patients, particularly in reducing fasting blood glucose, insulin, and lipid levels, suggesting a potential role of vitamin D in PCOS management. The long-term outcomes and most effective dose of vitamin D warrant further investigation in future research.

CLINICAL TRIAL NUMBER

Not applicable.

The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis

Introduction

Vaccine-related myocarditis is recognized as a rare but important complication, especially after mass-scale mRNA COVID-19 vaccination. Knowledge regarding how to minimize the risk is limited. As NK cells can mediate acute myocarditis after mRNA COVID-19 vaccination and vitamin D may inhibit NK cells via cytokine modulation, we hypothesize that the myocarditis side effect is related to a hypovitaminosis D - mRNA vaccine - hypercytokinemia - NK cell axis, which is amendable to clinical intervention.

Methods

Biochemical, immunophenotypic and genotyping assays were performed to examine vitamin D status and immune profiles in 60 patients who had BNT162b2 vaccine-related acute myocarditis.

Results

A high incidence of hypovitaminosis D (73.3%) was observed in these individuals with vaccine-related myocarditis, particularly in those presented with chest pain or intensive care unit (ICU) admission. Moreover, vitamin D level was negatively associated with peak serum cardiac troponin T level during vaccine-related myocarditis. Genotypically, the GC (vitamin D binding protein) rs4588T allele which encoded the GC2 isoform of vitamin D binding protein was a risk allele, whereas the GC1S isoform was protective. Mechanistically, hypovitaminosis D was associated with higher levels of cytokines pivotal for natural killer (NK) cells (particularly interleukin-1β (IL-1β), IL-12, Interferon-γ (IFN-γ), and IL-8) and higher percentage of CD69+ NK cells in blood, which in turn correlated with chest pain presentation.

Conclusion

These data support the hypothesis that vitamin D plays a crucial role in mitigating mRNA vaccine-related myocarditis by modulating proinflammatory cytokine milieu and subsequent unfavorable NK cell activation, laying a groundwork for preventive and treatment strategies.

It is time to update sun safety campaigns to recognise population diversity: Findings from two citizens' juries in Australia

ISSUE ADDRESSED

While the links between sun exposure and skin cancer are well known, the benefits of sun exposure, particularly as a source of vitamin D, are less well known. This paper reports on a deliberative study exploring public perspectives about sun exposure harms and benefits.

METHODS

Two citizens' juries were conducted in Brisbane and Adelaide to consider questions about sun exposure, vitamin D and health promotion. Members of the general population (jurors) listened to evidence from expert witnesses about the harms and benefits of sun exposure. Most witness sessions extended for 60 min, with 6 sessions over 2 days. At each citizens' jury, jurors were asked to listen to expert testimony, consider the evidence and make policy recommendations. The planning and design of the citizens' juries were informed by well-established citizens' jury methods.

RESULTS

Jurors proposed that Australia needs improved public information about the harms and benefits of sun exposure. They argued for information that supports personal decision-making that accounts for differences in skin tone and geographical region. Jurors agreed that Australia needs an updated sun safety campaign that reflects new research and addresses diversity. A one-size-fits-all approach to sun protection may no longer be appropriate.

CONCLUSIONS

While a new campaign should address both harms and benefits, jurors felt the need for skin cancer prevention outweighs the desirability of generating vitamin D through sun exposure. More nuanced public health messages are needed, which balance the need for skin protection and vitamin D, and acknowledge the diversity of Australia's population. SO WHAT?: Previous research studies are typically siloed into the separate areas of vitamin D or skin cancer research. This study incorporated both topics and pooled the views of participants in two citizens' juries who agreed on the need for improved information about the harms and benefits of sun exposure to reflect a modern Australian population.

UV index-based model for predicting synthesis of (pre-)vitamin D3 in the mediterranean basin

The importance of solar radiation for the body's ability to synthesize Vitamin D3 is well documented, yet the precise amount of sun exposure required to avoid Vitamin D insufficiency is less clear. To address this knowledge gap, this study sought to utilize the sun in a suitable period at the optimum dose by utilizing numerical simulations to determine the amount of Vitamin D3 synthesis in the skin according to season, time of day, and geographical location in Turkey. The study was carried out in three stages; in the first stage, daily, monthly, and annual values were determined in cases where the solar zenith angle has the active UV-B wavelength. The second stage determined the level of Vitamin D that can be synthesized in all skin types at 25% solar radiation exposure. In the third stage, the sun exposure time required for 1000 International Units (IU) for all skin types was calculated. According to the analysis, the yearly period of active synthesis of D3 on Earth lasts from the beginning of March to the third week of October. During the day, it is between 10:00 and 16:00. For 1000 IU/day, the average annual estimated times (minutes) are 5.05 for Type I, 6.3 for Type II, 7.6 for Type III, 11.35 for Type IV, 15.15 for Type V, and 25.25 for Type VI. The results of this paper will impact awareness for academic-medical users.

Balancing the risks and benefits of sun exposure: A revised position statement for Australian adults

OBJECTIVE

To describe the development of a new position statement regarding balancing the risks and benefits of sun exposure for Australian adults.

METHODS

We conducted a Sun Exposure Summit in March 2021, with presentations from invited experts and a workshop including representation from academic, clinical, policy, and patient stakeholder organisations. The group considered advice about balancing the risks and benefits of sun exposure for Australian adults and developed a revised consensus position statement.

RESULTS

The balance of risks and benefits of sun exposure is not the same for everybody. For people at very high risk of skin cancer, the risks of exposure likely outweigh the benefits; sun protection is essential. Conversely, people with deeply pigmented skin are at low risk of skin cancer but at high risk of vitamin D deficiency; routine sun protection is not recommended. For those at intermediate risk of skin cancer, sun protection remains a priority, but individuals may obtain sufficient sun exposure to maintain adequate vitamin D status.

CONCLUSIONS

The new position statement provides sun exposure advice that explicitly recognises the differing needs of Australia's diverse population.

IMPLICATIONS FOR PUBLIC HEALTH

Mass communication campaigns should retain the focus on skin cancer prevention. The new position statement will support the delivery of personalised advice.