Latest Knowledge on the Role of Vitamin D in Hypertension

Association between dietary magnesium intake and muscle mass among hypertensive population: evidence from the National Health and Nutrition Examination Survey

BACKGROUND

Magnesium is critical for musculoskeletal health. Hypertensive patients are at high risk for magnesium deficiency and muscle loss. This study aimed to explore the association between magnesium intake and muscle mass in patients with hypertension.

METHODS

In this population-based cross-sectional study, 10,279 U.S. hypertensive adults aged 20 years or older were derived from the National Health and Nutrition Examination Survey in 1999-2006 and 2011-2018. Magnesium (Mg) intake from diet and supplements was assessed using 24-hour diet recalls. Muscle mass was evaluated by appendicular skeletal muscle mass index (ASMI, total ASM in kilograms [kg] divided by square of height in meters [m2]). The association of Mg intake with ASMI was estimated using weighted multivariable-adjusted linear regression models and restricted cubic splines.

RESULTS

Dose-response analyses showed a positive linear correlation between dietary Mg intake and ASMI. Every additional 100 mg/day in dietary Mg was associated with 0.04 kg/m2 (95% confidence interval [CI] 0.02-0.06 kg/m2) higher ASMI. The ASMI in participants who met the recommended dietary allowance (RDA) for dietary Mg was 0.10 kg/m2 (95% CI 0.04-0.16 kg/m2) higher than those whose dietary Mg was below estimated average requirement (EAR). However, the relationship of Mg intake from supplements with ASMI was not identified.

CONCLUSION

Higher level of dietary Mg intake rather than Mg supplements was associated with more muscle mass in U.S. adults with hypertension, which highlights the importance of meeting the recommended levels for dietary Mg intake.

Calcitriol ameliorates motor deficits and prolongs survival of Chrne-deficient mouse, a model for congenital myasthenic syndrome, by inducing Rspo2

Signal transduction at the neuromuscular junction (NMJ) is compromised in a diverse array of diseases including congenital myasthenic syndromes (CMS). Germline mutations in CHRNE encoding the acetylcholine receptor (AChR) ε subunit are the most common cause of CMS. An active form of vitamin D, calcitriol, binds to vitamin D receptor (VDR) and regulates gene expressions. We found that calcitriol enhanced MuSK phosphorylation, AChR clustering, and myotube twitching in co-cultured C2C12 myotubes and NSC34 motor neurons. RNA-seq analysis of co-cultured cells showed that calcitriol increased the expressions of Rspo2, Rapsn, and Dusp6. ChIP-seq of VDR revealed that VDR binds to a region approximately 15 ​kbp upstream to Rspo2. Biallelic deletion of the VDR-binding site of Rspo2 by CRISPR/Cas9 in C2C12 myoblasts/myotubes nullified the calcitriol-mediated induction of Rspo2 expression and MuSK phosphorylation. We generated Chrne knockout (Chrne KO) mouse by CRISPR/Cas9. Intraperitoneal administration of calcitriol markedly increased the number of AChR clusters, as well as the area, the intensity, and the number of synaptophysin-positive synaptic vesicles, in Chrne KO mice. In addition, calcitriol ameliorated motor deficits and prolonged survival of Chrne KO mice. In the skeletal muscle, calcitriol increased the gene expressions of Rspo2, Rapsn, and Dusp6. We propose that calcitriol is a potential therapeutic agent for CMS and other diseases with defective neuromuscular signal transmission.

Evaluation of the Effect of Vitamin D Treatment on Cardiac Function in Non-Obese Female Adolescents with Vitamin D Deficiency in Türkiye: A Cross-Sectional Study

BACKGROUND

Vitamin D deficiency may cause adverse effects on the cardiovascular system as well as many other systems. The risk of vitamin D deficiency increases during adolescence, when the growth rate is high, due to reasons such as limited sun exposure, inadequate dietary calcium, and vitamin D intake.

AIM

To evaluate the effect of daily 2000 IU vitamin D supplementation for 12 weeks on cardiac function in non-obese adolescent girls with vitamin D deficiency.

METHODS

This cross-sectional study was carried out between September 2021 and June 2022. A total of 108 non-obese adolescent girls having 25-hydroxyvitamin D [25(OH)D] levels below 12 ng/mL were given daily 2000 IU vitamin D orally for 12 weeks. Serum levels of 25(OH)D, alkaline phosphatase, parathormone, calcium, phosphate, and cardiac function were determined before and after treatment.

RESULTS

After treatment, the 25(OH)D levels were above 20 ng/mL in 90.8% of the adolescents. The parathormone and alkaline phosphatase levels decreased, while the phosphate levels increased. Echocardiographic tissue Doppler studies showed positive changes in some systolic and diastolic function indicators. In addition, the myocardial performance index decreased from 0.42 ± 0.03 to 0.40 ± 0.03 (P < 0.001) in the left ventricle, from 0.43 ± 0.03 to 0.38 ± 0.03 (P < 0.001) in the right ventricle, and from 0.41 ± 0.04 to 0.38 ± 0.02 (P < 0.001) in the interventricular septum after vitamin D treatment as compared to pretreatment.

CONCLUSION

It was observed that administration of 2000 IU vitamin D treatment for a period of 12 weeks to non-obese adolescent girls with vitamin D deficiency contributed positively to cardiac systolic and diastolic function.

Effects of Gender and Vitamin D on Vascular Reactivity of the Carotid Artery on a Testosterone-Induced PCOS Model

The negative cardiovascular effects of polycystic ovary syndrome (PCOS) and vitamin D deficiency (VDD) have been discussed previously; however, the sex differences between PCOS females and males are not yet known. Our aim was to investigate the effect of PCOS and VDD in the carotid artery of male and female Wistar rats. Females were treated with transdermal testosterone (Androgel) for 8 weeks, which caused PCOS. VDD and vitamin D supplementation were accomplished via diet. The carotid arteries' contraction and relaxation were examined using myography. Receptor density was investigated using immunohistochemistry. In PCOS females, angiotensin receptor density, angiotensin II-induced contraction, androgen receptor optical density, and testosterone-induced relaxation increased. The increased contractile response may increase cardiovascular vulnerability in women with PCOS. As an effect of VDD, estrogen receptor density increased in all our groups, which probably compensated for the reduced relaxation caused by VDD. Testosterone-induced relaxation was decreased as a result of VDD in males and non-PCOS females, whereas this reduction was absent in PCOS females. Male sex is associated with increased contraction ability compared with non-PCOS and PCOS females. VDD and Androgel treatment show significant gender differences in their effects on carotid artery reactivity. Both VDD and PCOS result in a dysfunctional vascular response, which can contribute to cardiovascular diseases.

Vitamin D deficiency and development of complications in individuals with type 1 and type 2 diabetes: A cohort study

AIMS

To investigate vitamin D deficiency as a risk marker for complications in individuals with type 1 and type 2 diabetes.

METHODS

A cohort study including 1448 adults with type 1 and 770 with type 2 diabetes. Individuals in the decile with lowest vitamin D level were classified as vitamin D deficient. Outcomes based on medical records and registers included mortality, major adverse cardiovascular event (MACE), heart failure, a composite kidney endpoint, albuminuria progression and sight-threatening eye disease. Risk in individuals with vitamin D deficiency was compared to the remaining using adjusted Cox proportional hazards models.

RESULTS

Vitamin D deficiency was associated with higher risk of MACE (adjusted hazard ratio (HR): 2.6; 95 % confidence interval (CI): 1.3-5.2) in type 1, but not in type 2 diabetes. Risk of heart failure was higher in individuals with vitamin D deficiency in both cohorts (HR (95%CI): 16 (4.8-50) in type 1 and 2.4 (1.1-5.5) in type 2 diabetes). Vitamin D deficiency was not associated with development of microvascular complications or mortality.

CONCLUSIONS

Vitamin D deficiency was a risk marker for MACE and heart failure in type 1 and for heart failure in type 2 diabetes, but not for microvascular complications or all-cause mortality.

Immunomodulatory Effects of Vitamin D in Respiratory Tract Infections and COVID-19 in Children

Acute respiratory tract infections (ARTIs) are one of the main reasons that the pediatric population goes to the doctor. The connection between ARTI and vitamin D (VD) is currently debated by the medical community, and so far, there has been little agreement with regard to the ideal level of 25(OH)D concentration that would provide protection for the respiratory tract, or the effectiveness of its administration in the treatment of respiratory infections. The purpose of this literature review was to bring attention to the immunomodulatory and antiviral function of vitamin D and its relation to the respiratory system by examining the main ARTIs, including SARS-CoV-2. The latter has affected the pediatric population in different ways, from asymptomatic patients to severe forms with multisystem inflammatory syndrome in children (MIS-C). Although there are not much clinical data on the SARS-CoV-2 disease in the pediatric population worldwide, we tried to find out whether there is a connection between the severity of this disease, other ARTIs, and vitamin D supplementation. We also aimed to find out if 25OHD deficiency had an adverse effect on the evolution of the disease and the recovery period in the case of younger patients affected by COVID-19. For this literature review, the PICO framework was selected as the methodological approach. Our results demonstrated many methods by which this vitamin may lower the risk of ARTI with regard to the COVID-19 infection. Despite these significant advancements, more research is needed to support the idea that 25(OH)D concentration can influence the evolution of respiratory tract infections in children.

Vitamin D and Vitamin D Binding Protein in Health and Disease 2.0

Vitamin D, often referred to as the "sunshine nutrient", has gained considerable attention in recent years due to its multifaceted impact on health and disease [...].