• Journal of Preventive Medicine and Public Health
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• v.51 no.2
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• pp.92-99
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• 2018

Objectives: Albuminuria has emerged as a biomarker for several medical conditions, and vitamin D has received attention due to its associations with various disorders. We evaluated the association between low serum vitamin D levels and prevalent albuminuria by sex in the Korean general population. Methods: We analyzed 9823 participants (4401 males, 5422 females) from the Korea National Health and Nutrition Examination Survey 2011-2012 (KNHANES V-2), and categorized them as having a normal range of vitamin D levels, vitamin D insufficiency, or vitamin D deficiency. A multivariable logistic regression model was used to compare the risk of albuminuria across these groups. Stratified analyses were conducted by smoking status, obesity, and renal function. Results: Albuminuria was found in 325 of the 4401 male participants (7.4%) and in 455 of the 5422 female participants (8.4%). Among the males, vitamin D deficiency was associated with an odds ratio (OR) for albuminuria of 1.78 (95% confidence interval [CI], 1.07 to 2.97, p<0.05). However, such an association was not found in females. The association was stronger in male current smokers (OR, 3.54; 95% CI, 1.47 to 8.50; p=0.005). Conclusions: The findings of this study suggest that sex differences exist in the association between serum vitamin D deficiency and albuminuria. Additionally, we observed that the association was stronger in current smokers than in the overall male population, but was not seen in non-smokers. Therefore, different approaches by sex and smoking status might be needed when considering using vitamin D as a biomarker for renal function.

• Korean Journal of Community Nutrition
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• v.24 no.3
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• pp.245-256
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• 2019

Objectives: Although the number of laboratory workers is constantly increasing every year, few studies have been conducted on the health and nutritional status of these research workers. This study determined the health status of laboratory workers by analyzing their anthropometric indices, dietary life, vitamin D status and blood clinical indices. Methods: The subjects consisted of 100 female laboratory workers. This study investigated their diet, anthropometric indices, vitamin D status and blood clinical indices. The subjects were divided into two groups according to their duration of working in a laboratory (<1 year, $${\geq}_-1year$$). Results: The average age and body mass index (BMI) of subjects were 23.18 years and $21.51kg/m^2$, respectively Those subjects with over 1 year employment ($${\geq}_-1year$$) had a significantly higher waist-hip ratio than that of the subjects with the less than 1 year employment (<1 year). The mean serum vitamin D level of all the subjects was 10.04 ng/mL, which is close to a level of vitamin D deficiency. There was a significantly higher average intake of calories in the over 1 year employment group as compared to that of the less than 1 year employment group. The frequency of eating sweet snacks was significantly higher for the over 1 year employment group. The correlation analysis showed a significant positive correlation between the serum 25-(OH)-vitamin D level and the time of exposure to sunlight, while dietary intake of vitamin D did not show correlation with the serum 25-(OH)-vitamin D level. However, the serum 25-(OH)-vitamin D level was also negatively correlated with both the percentage of body fat and visceral fat. Conclusions: Laboratory workers are a very high risk group in terms of their nutritional status of vitamin D. Therefore, they need greater time of exposure to sunlight as well as increasing their dietary consumption of vitamin D. In addition, it is important for laboratory worker to practice regular and balanced dietary habits in order to maintain a healthy life.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.131-143
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• 1984

150 rats weighting about 150gm were devided into control group of 80 and experimental group of 70. Control group was subdivided into the irradiated vitamin D injection group and X-ray irradiated group. Experimental group was given 2.0mg ergocalciferol by four intramuscular injection prior to X-ray irradiation with single 800 rads and 1,500 rads respectively. Experimental animals from each group was sacrificed after 1, 3, 7, 14, and 28 days and their incisors were investigated by histopathological examination. The results were as follows; 1. In the irradiated groups, it showed dentin hypoplasia and formation of dentinoid substance caused by degeneration of odontoblast at the early stage. Especially, 1,500 rads group which was severely effected showed formation of osteoid dentin at the apical portion and severe injuries of dental papilla at the first week. 2. In the vitamin D2 administration group, it showed thinned dentin layer at the early stage but, taking time, predentin and dentin layer was thickened. At the fourth week, dentin was chiefly composed of interglobular dentin, especially in the lingual portion. 3. Using in combination of overdose vitamin D2 administration and X-ray irradiation, it effected severely odontoblast, undifferentiated mesenchymal cells around tooth germ and pulp tissue. At the early stage, dentin layer was thinned but, taking time, it was thickened and composed of interglobular dentin caused by calcification of predentin layer. 4. In 800 rads irradiation after the overdose vitamin D2 administration, it showed formation of osteoid dentin in the lingual portion at the first week. In the 1,500 rads irradiation after the overdose vitamin D2 administration, it showed formation of osteoid dentin and degeneration of ameloblast in both buccal and lingual portion at the first week, and enamel hypoplasia caused by edema and loss of polarity of ameloblasts at the second week. 5. By the entire experiment, the overdose vitamin D2 administration and X-ray irradiation effected severely odontoblasts, undifferentiated mesenchymal cells of dental papilla, and primitive cells of tooth germ among the dental tissue. Especially using combination of overdose vitamin D2 administration and X-ray irradiation also effected ameloblasts, resulting in enamel hypoplasia.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.571-577
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• 2012

This study was carried out to develop an analytical method for the determination of vitamin D in infant formula. Vitamin D was determined by column-switching high-performance liquid chromatography (HPLC) equipped with a reversed phase column and UV detector after saponification and extraction of the formula with an organic solvent. A preseparation column ($C_8$), focusing column ($C_{18}$), analytical column ($C_{18}$) and UV-Vis detector (254 nm) were used. The limits of detection (LOD) and the limits of quantification (LOQ) for vitamin D were estimated to be $1.51{\mu}g/kg$ and $4.95{\mu}g/kg$, respectively. The linearity, recovery, precision and accuracy of the analytical method for vitamin D were evaluated through the application of a SRM (Standard Reference Material) 1846 (National Institute of Standard & Technology, USA). The linearity of this method was calculated with a value of the coefficient of determination ($r^2$) ${\geq}0.9999$. The recovery of vitamin D was $85.20{\pm}3.00%$. The intra-assay precision for vitamin D was between $1.68{\pm}0.03%$ and $5.75{\pm}0.33%$, and the inter-assay precision for vitamin D ranged from $1.73{\pm}0.03%$ to $2.96{\pm}0.09%$. The intra-assay accuracy for vitamin D was between $100.03{\pm}2.77%$ and $102.01{\pm}0.59%$, and the inter-assay accuracy for vitamin D ranged from $99.00{\pm}1.53%$ to $102.01{\pm}3.04%$. The proposed method is optimal for the separation and quantification of vitamin D from infant formula.

• Journal of the Korean Society of School Health
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• v.30 no.2
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• pp.146-153
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• 2017

Purpose: The purpose of this study was to identify the association between physical activity and vitamin D deficiency status among Korean adolescents. Methods: This is cross-sectional analysis of Korean adolescents aged 10-18 years from the 5th Korea National Health and Nutrition Examination Survey(KNHANES 2010-2012; n=2,384). We estimated the prevalence of vitamin D deficiency and identified the correlations with the strength of physical activity. $x^2$ test, t-test, and multiple logistic regression using complex sample analysis were done. The odds ratio of vitamin D deficiency by physical activity was calculated using complex sample multivariate logistic regression analysis. Results: The prevalence of vitamin D deficiency was 78.2%. The mean serum 25 (OH) D level in deficiency group and non-deficiency group was 14.4ng/mL, 23.7ng/mL respectively. Differences by age strata (the prevalence ranging from 68.5% to 86.3%) and gender (78.6% for boy and 84.5% for girl) were identified. Among adolescents aged 16-18 or girl in vigorous physical activity, a significant correlation between vitamin D deficiency and physical activity was observed, whereas no significant correlation were found among adolescents in moderate physical activity. Conclusion: In conclusion, vigorous physical activity was associated with vitamin D deficit in Korean adolescents. Thus, intervention programs enhancing vigorous activity than moderate activity need to be developed in schools and community.

• Journal of Preventive Medicine and Public Health
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• v.55 no.4
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• pp.321-333
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• 2022

Objectives: Extensive evidence links low vitamin D status and comorbidities with coronavirus disease 2019 (COVID-19) outcomes, but the results of published studies are contradictory. Therefore, we investigated the association of lower levels of vitamin D and comorbidities with the risk of COVID-19 infection. Methods: We searched MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for articles published until August 20, 2021. Sixteen eligible studies were identified (386 631 patients, of whom 181 114 were male). We included observational cohort and case-control studies that evaluated serum levels of vitamin D in COVID-19-positive and COVID-19-negative patients. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated. Results: Significantly lower vitamin D levels were found in COVID-19-positive patients (MD, -1.70; 95% CI, -2.74 to -0.66; p=0.001), but with variation by study design (case-control: -4.04; 95% CI, -5.98 to -2.10; p<0.001; cohort: -0.39; 95% CI, -1.62 to 0.84; p=0.538). This relationship was more prominent in female patients (MD, -2.18; 95% CI, -4.08 to -0.28; p=0.024) than in male patients (MD, -1.74; 95% CI, -3.79 to 0.31; p=0.096). Male patients showed higher odds of having low vitamin D levels (odds ratio [OR], 2.09; 95% CI, 1.38 to 3.17; p<0.001) than female patients (OR, 1.17; 95% CI, 0.74 to 1.86; p=0.477). Comorbidities showed inconsistent, but generally nonsignificant, associations with COVID-19 infection. Conclusions: Low serum vitamin-D levels were significantly associated with the risk of COVID-19 infection. This relationship was stronger in female than in male COVID-19 patients. Limited evidence was found for the relationships between comorbidities and COVID-19 infection, warranting large population-based studies to clarify these associations.

• Nutrition Research and Practice
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• v.6 no.1
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• pp.86-90
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• 2012

This study assessed the association between vitamin D sufficiency (serum 25(OH)D ${\geq}30ng/mL$) and alcohol consumption using data from the Korea National Health and Nutrition Examination Survey conducted in 2009. The following characteristics were obtained in 7,010 Korean participants ${\geq}19$-years-of-age: serum 25(OH)D level, alcohol consumption (drinking frequency, drinking number of alcoholic beverages on a typical occasion, average daily-alcohol intake), and potential confounders (age, residence, housing status, occupation, total fat and lean mass, smoking, physical activity, history of liver diseases, liver function, and daily intake of energy, protein, and calcium). After adjusting for confounders, vitamin D sufficiency in men was significantly associated with drinking frequency, number of alcoholic drinks consumed, and average daily alcohol intake; odds ratio of 1.21-1.72, 2.17-3.04, and 2.27-3.09, respectively. Increase in the three alcohol drinking-related behaviors was also linearly associated with increase in serum 25(OH)D level in men. By comparison, there was no significant association between alcohol intake and serum 25(OH)D level in women. The positive association between vitamin D sufficiency and alcohol consumption was evident only in Korean men.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.237-240
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• 1999

The presence of polyostotic fibrous dysplasia of bone, hyperpigmented skin macules, and precocious sexual development in children is known as the McCune-Albright syndrome. In addition to the described in McCune-Albright syndrome, other endocrinopathies have been reported including hyperthyroidism, acromegaly, Cushing syndrome and vitamin D resistant rickets. The case describes a 6-year-old boy showing bony deformities due to polyostotic fibrous dysplasia, hyperpigmented skin macules, hyperthyroidism and vitamin D resistant rickets. The purpose of this report is to describe a patient of McCune-Albright syndrome with vitamin D resistant rickets which is very rare.

• Journal of Korean Biological Nursing Science
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• v.18 no.3
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• pp.185-191
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• 2016

Purpose: The purpose of this study is to understand the effect of taking calcium/vitamin D supplements and performing Taekkyeon exercises on the frailty of the elderly targeting a vulnerable senior social group. Methods: A total of 124 people aged 65 and older consisting of 60 persons in the experimental group, and 64 persons in the control group participated in this study, and this study is a non-equivalent control group pre/post-test design quasi-experimental study. This study analyzed the homogeneity between the experimental group and the control group using a chi-square test and t-test while analyzing the difference in the degree of frailty and bone density with the practice of Taekkyeon and a calcium agent using t-test and GEE. Results: The study results showed that the frailty and bone density of the experimental group significantly improved. Conclusion: Through this study, it was confirmed that calcium/vitamin D intake and Taekkyeon exercises were an effective intervention which strengthened the elderly's physical condition.

• Journal of Nutrition and Health
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• v.49 no.6
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• pp.437-446
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• 2016

Purpose: The purpose of this study was to estimate dietary intake of vitamin D and the relationship between serum 25-hydroxyvitamin D (25OHD) concentration and bone mineral density (BMD) in Korean adults using the 2011 data from the Korea National Health and Nutrition Examination Survey. Methods: Daily intake of vitamin D and ratio of subjects that consumed less vitamin D than adequate intake (AI) were estimated in 4,879 Korean adults. The relationship between daily intake of vitamin D and serum 25OHD and BMD were analyzed. Results: Average daily intakes of vitamin D were $3.84{\pm}0.23{\mu}g/day$ for men and $2.22{\pm}0.11{\mu}g/day$ for women. Approximately 72~97% of men and 80~99% of women consumed less than the AI of vitamin D for Koreans. Serum 25OHD concentration increased with age, and the ratios of serum vitamin D deficiency (< 20 ng/mL) were 47.8~81.1% for men and 59.4~92.8% for women. Average intake of vitamin D was higher in subjects aged < 50 yr than in those ${\geq}50yr$, but lower in serum 25OHD concentration. In subjects aged < 50 yr, serum 25OHD was higher in subjects that consumed $10{\mu}g/day$ of vitamin D than in those that consumed less than $5{\mu}g/day$. In female subjects aged ${\geq}50yr$, average intake of vitamin D was associated with higher bone mineral density. Conclusion: It was found that dietary intake of vitamin D could increase serum 25OHD concentration in young adults and bone mineral density in old women. Therefore, nutrition policies for enriched foods with vitamin D and nutrition education to consume more vitamin D-rich foods are needed to ameliorate vitamin D status of the Korean population. Adequate intake for Korean population aged < 50 yr might be adjusted upwardly up to $10{\mu}g/day$.