• Clinical Nutrition Research
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• v.13 no.3
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• pp.165-175
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• 2024

This study aimed to assess the relationship between serum levels of vitamin D with anthropometric indices, lipid profile and vascular inflammatory factors, in patients who candidate for coronary artery bypass grafting (CABG). This analytical cross-sectional study was conducted in patients who were candidate for CABG. Demographic information, medical records, anthropometric indicators, blood samples, and physical activity of 150 patients were collected. 146 participants with mean ± standard deviation of age: 61.8 ± 10.0 years and body mass index: 26.9 ± 3.7 kg/m² completed the study. Based on serum levels of vitamin D, patients were divided into 2 groups; groups with sufficient (≥ 30 ng/mL) and insufficient amount of vitamin D (< 30 ng/mL). The 30.14% of the patients had serum vitamin D deficiency. Ejection fraction (EF) % between the 2 groups had significant difference. Unexpectedly the EF% increased 7% in patients with insufficient level of vitamin D (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.03-1.11; p = 0.001). Vitamin D status had a significant inverse association with body weight. The odds of vitamin D deficiency significantly increased by 4% with increasing one kg in weight (OR, 1.04; 95% CI, 1-1.08; p = 0.044). There were no significant association between serum vitamin D level and intra cellular adhesion molecule-1, interleukin-17, fasting blood glucose, and lipid profile (p > 0.05). Considering the inverse association observed between serum vitamin D with EF% and body weight, vitamin D may play a role in modulating of these indices.

• Journal of Hospice and Palliative Care
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• v.18 no.2
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• pp.120-127
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• 2015

Purpose: We aimed to investigate how serum vitamin D levels are related to survival of terminally ill cancer patients. Methods: From May 2012 through June 2013, a retrospective chart review was performed on 96 hospice patients. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with severe vitamin D deficiency and Coxcy and Coxional hazard analyses were used to evaluate effects on survival. Results: The mean vitamin D level in patients was $8.60{\pm}7.16ng/ml$. Vitamin D was severely deficient (<10 ng/ml) in 75 patients (78.2%), deficient (10~20 ng/ml) in 13 patients (13.5%), relatively insufficient (21~29 ng/ml) in five patients (8.3%) and sufficient ((t ng/ml) in three patients (3.1%). Hyperbilirubinemia (${\geq}1.2g/dl$) was the only factor associated with severe vitamin D deficiency according to the multiple logistic regression analysis (Odds ratio, OR=18.48, P<0.05). Although hyperbilirubinemia showed a strong association with survival (Hazard ratio, HR=2.25, P<0.01), no association was found between severe vitamin D deficiency and survival (HR=1.15, P>0.05) in Cox's proportional hazard analysis. Conclusion: Although serum vitamin D levels were severely low in terminally ill cancer patients, we found no association between severe vitamin D deficiency and patient survival.

• Asian Spine Journal
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• v.12 no.6
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• pp.1127-1145
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• 2018

Several theories have been proposed to explain the etiology of adolescent idiopathic scoliosis (AIS) until present. However, limited data are available regarding the impact of vitamin D insufficiency or deficiency on scoliosis. Previous studies have shown that vitamin D deficiency and insufficiency are prevalent in adolescents, including AIS patients. A series of studies conducted in Hong Kong have shown that as many as 30% of these patients have osteopenia. The 25-hydroxyvitamin D3 level has been found to positively correlate with bone mineral density (BMD) in healthy adolescents and negatively with Cobb angle in AIS patients; therefore, vitamin D deficiency is believed to play a role in AIS pathogenesis. This study attempts to review the relevant literature on AIS etiology to examine the association of vitamin D and various current theories. Our review suggested that vitamin D deficiency is associated with several current etiological theories of AIS. We postulate that vitamin D deficiency and/or insufficiency affects AIS development by its effect on the regulation of fibrosis, postural control, and BMD. Subclinical deficiency of vitamin K2, a fat-soluble vitamin, is also prevalent in adolescents; therefore, it is possible that the high prevalence of vitamin D deficiency is related to decreased fat intake. Further studies are required to elucidate the possible role of vitamin D in the pathogenesis and clinical management of AIS.

• Journal of the Korean Dietetic Association
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• v.23 no.1
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• pp.39-53
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• 2017

Insufficient vitamin D intake is a major health problem around the world. Recently, many studies have suggested that vitamin D intake may influence insulin resistance. However, little is known about the association between vitamin D and diabetes mellitus. The aim of this study was to investigate the association between serum 25-hydroxy vitamin D (25(OH)D) levels and diabetes mellitus in Korean adults. This study was a cross-sectional analysis of 3,686 participants of the Korean National Health and Nutrition Examination Survey (KNHANES) 2013~2014 aged 19 years and higher. The results showed that the mean serum 25-hydroxy vitamin D (25(OH)D) level in Korean adults was 16.77 ng/mL, and 74.2% of them had an insufficient serum 25-hydroxy vitamin D (25(OH)D) level (below 20 ng/mL). In normal and pre-diabetic groups, the serum 25-hydroxy vitamin D (25(OH)D) level significantly increased with age (P<0.001), but there was no significant difference relative to age in the diabetic group. Low vitamin D levels (25-hydroxy vitamin D < 10 ng/mL) were associated with increased fasting blood glucose levels, compared with optimal vitamin D levels (25-hydroxy vitamin D > 30 ng/mL), after adjusting for variables that may affect fasting blood glucose, but this result was not significant. In conclusion, although no significant association was observed between diabetes prevalence and vitamin D levels in this study, further studies are needed because the effect of vitamin D on diabetes remains controversial. This nutrient plays a crucial role in the body, and levels are insufficient in the Korean population.

• Tuberculosis and Respiratory Diseases
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• v.79 no.3
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• pp.153-157
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• 2016

Background: Vitamin D is known to have diverse effects on various systems in the body. There is evidence to suggest that a link exists between the serum vitamin D status and tuberculosis. The present study was designed to assess the alterations in serum 25-hydroxyvitamin D levels in newly diagnosed sputum acid fast bacilli (AFB) positive pulmonary tuberculosis patients and to study the association, if any, between serum vitamin D levels and different levels of sputum smear positivity. Methods: Serum 25-hydroxyvitamin D levels were estimated in 65 sputum AFB positive pulmonary tuberculosis patients and 65 age and gender-matched healthy controls. Results: The levels of serum 25 hydroxy-vitamin D in tuberculosis patients were not statistically different from the levels of serum 25 hydroxy-vitamin D in healthy controls. However, among patients with pulmonary tuberculosis, there was a significant negative correlation between the levels of serum 25 hydroxy-vitamin D and levels of sputum positivity. Conclusion: Serum vitamin D levels negatively correlates with bacterial load in patients with active pulmonary tuberculosis.

• Journal of Practical Agriculture & Fisheries Research
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• v.18 no.1
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• pp.3-12
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• 2016

Vitamin D plays a vital role in maintaining blood concentrations of Ca and P. In lipid metabolism, vitamin D is also known to negatively affect the development of adipocytes, but it has received little attention with regard to improve marbling score in beef cattle via restricting its supply. Recently, the method of feeding fat soluble vitamins(including vitamin D)-deficient diets in Korean native cattle (Hanwoo) has been spread by feed companies and TMR plants. But proper guidelines in feeding vitamin D-deficient diets should be provided, otherwise it can adversely affect the health of cattle. To maximize marbling score, a controlled level of vitamin D in blood needs to be maintained and the proper period for feeding vitamin D-deficient diets should be provided. This review was conducted to highlight the regulatory effects of vitamins D on adipocyte differentiation, and provide information on improving beef quality grades in relation to feeding vitamin D-deficient diets in beef cattle.

• Journal of Nutrition and Health
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• v.41 no.2
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• pp.127-134
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• 2008

The effects of vitamin $D_{3}$ supplementation on bone mineral density and bone mineral content in ovariectmized rats were investigated. Forty female Sprague-Dawley rats (body weight 180 g) were divided into two group, ovariectomy and Sham groups, which were each randomly divided into two subgroups that were fed casein and casein supplemented with vitamin $D_{3}$ diets. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXlmus (GE Lunar Co, Wisconsin, USA) in spine and femur on 6 weeks after feeding. Osteocalcin and urinary DPD crosslinks value were measured as markers of bone formation and resorption. The body weight gain and food efficiency ratio (FER) were higher in OVX groups than in Sham groups regardless of diets. Serum Ca concentration and urinary Ca excretion were higher in vitamin $D_{3}$ supplemented group than in casein group in Sham and OVX. Crosslinks values were higher in OVX groups than in Sham groups. Spine BMD and femur BMD of ovariectomy group were significantly lower than Sham groups, however vitamin $D_{3}$ supplemented groups were significantly higher than control groups in Sham and OVX. In conclusion, dietary vitamin $D_{3}$ supplementation on ovariectimized rats were significantly increased bone mineral density and bone mineral content in spine and femur.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.2
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• pp.125-134
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• 2024

Objective: Vitamin D deficiency is a major problem for human health worldwide. The mechanisms of vitamin D in the male reproductive system are unknown. After coronavirus disease 2019 (COVID-19) vaccines were developed, doubts were raised about their possible effects on male fertility. Based on vitamin D's function in the immune system, its potential role as an adjuvant for COVID-19 vaccines is intriguing. The aims of this study were to assess the effects of vitamin D first on sperm parameters and sex hormones, and then as an immune adjuvant on sperm parameters and sex hormones after study participants had received their second doses of COVID-19 vaccines. Methods: Phase 1 (before the COVID-19 pandemic) included 72 men with idiopathic infertility, and phase 2 had 64 participants who received two doses of COVID-19 vaccines. Both groups were instructed to take 50,000 IU of vitamin D twice monthly for 3 months. Sperm parameters and sex hormones were assessed pre-and post-supplementation. Results: Regular vitamin D intake for 3 months significantly increased the participants' vitamin D levels (p=0.0001). Both phases showed a positive correlation between vitamin D intake and sperm parameters. Vaccination had no negative effects on sperm parameters and sex hormones. Vitamin D was associated with follicle-stimulating hormone (p=0.02) and testosterone (p=0.0001) in phase 2 after treatment. Conclusion: Our results support vitamin D supplementation as an immune adjunct to COVID-19 vaccination for improving sperm parameters and hormone levels. COVID-19 vaccination is not harmful for male fertility potential, and vitamin D is an effective factor for male fertility.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.3
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• pp.321-330
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• 2020

Objectives: The purpose of this study was to compare vitamin D levels, sleep quality, and anxiety symptoms between shift workers and daytime workers and analyze the mediating effect of vitamin D and sleep quality between shift work and anxiety symptoms. Methods: The subjects of the study were 6744 people who received a medical examination while working for an electronics manufacturing company in 2016. We evaluated their shift work, vitamin D levels, sleep quality, and anxiety symptoms with blood samples and questionnaires. Chi-square test, t-test and path statistical analysis were performed. Results: The shift workers had significantly higher symptoms of anxiety than the day workers, significantly lower levels of vitamin D in the blood, and significantly poorer quality of sleep. The results of the pathway analysis confirmed that blood vitamin D and sleep quality had a mediating effect between shift work and anxiety symptoms. Conclusions: Shift workers should be constantly paying attention to mental health effects such as anxiety symptoms. Shift workers should also be alerted of the risk of vitamin D deficiency, encouraged about sun exposure and vitamin D intake, and required to undergo training and counseling on sleep hygiene.

• Toxicological Research
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• v.33 no.1
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• pp.49-54
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• 2017

Vitamin D3 is a fat-soluble secosteroid responsible for enhancing intestinal absorption of calcium, iron, and other materials. Vitamin D3 deficiency, therefore, can cause health problems such as metabolic diseases, and bone disorder. Female sex hormones including estrogen and progesterone are biosynthesized mainly in the granulosa cells of ovary. In this study, we isolated granulosa cells from porcine ovary and cultured for the experiments. In order to examine the effect of vitamin D3 on the ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by real-time PCR and Western blot assay. The production of estrogen from the granulosa cells was also measured by the ELISA assay. Genes associated with follicle growth were not significantly altered by vitamin D3. However, it increases expression of genes involved in the estrogen-biosynthesis. Further, estrogen concentrations in porcine granulosa cell-cultured media increased in response to vitamin D3. These results showed that vitamin D3 is a powerful regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss.