• Journal of Nutrition and Health
• /
• v.47 no.2
• /
• pp.113-123
• /
• 2014

Purpose: Vitamin D has been known to play an important role in the central nervous system and brain functions in the human body, and cumulative evidence has shown that vitamin D deficiency might be linked with various mental health conditions. Epidemiologic studies have shown that vitamin D deficiency may be associated with higher risk of depression in the US and European populations. However, limited information is available regarding the association between vitamin D status and depression in the Korean population. The objective of this study was to examine the associations between vitamin D levels and prevalence of depression. Methods: We conducted a cross-sectional analysis using nationally representative data from the 2008-2010 Korean National Health and Nutrition Examination Survey from which serum 25-hydroxyvitamin D concentrations were available. A total of 18,735 adults who had available demographic, dietary, and lifestyle information were included in our analysis. We defined "depression" with a diagnosis by a physician. "Depressed condition" was defined as having feelings of sadness or depression without diagnosis by a physician. Results: The prevalence of depression was 1.63% and 5.43% in Korean men and women, respectively; 12.5% of men and 26.1% of women were defined as the group having depressed conditions. In multivariate logistic regression models, no significant associations were observed between vitamin D status and prevalence of depression or depressed conditions in Korean men and women. Conclusion: We found no association between vitamin D insufficiency and depression/depressed conditions in Korean adults. Future large prospective studies and randomized controlled trials are needed to confirm this relationship.

• Tuberculosis and Respiratory Diseases
• /
• v.77 no.2
• /
• pp.73-80
• /
• 2014

Background: Low levels of serum vitamin D is associated with several lung diseases. The production and activation of matrix metalloproteinases (MMPs) may play an important role in the pathogenesis of emphysema. The aim of the current study therefore is to investigate if vitamin D modulates the expression and activation of MMP-2 and MMP-9 in human lung fibroblasts (HFL-1) cells. Methods: HFL-1 cells were cast into three-dimensional collagen gels and stimulated with or without interleukin-$1{\beta}$ (IL-$1{\beta}$) in the presence or absence of 100 nM 25-hydroxyvitamin D (25(OH)D) or 1,25-dihydroxyvitamin D ($1,25(OH)_2D$) for 48 hours. Trypsin was then added into the culture medium in order to activate MMPs. To investigate the activity of MMP-2 and MMP-9, gelatin zymography was performed. The expression of the tissue inhibitor of metalloproteinase (TIMP-1, TIMP-2) was measured by enzyme-linked immunosorbent assay. Expression of MMP-9 mRNA and TIMP-1, TIMP-2 mRNA was quantified by real time reverse transcription polymerase chain reaction. Results: IL-$1{\beta}$ significantly stimulated MMP-9 production and mRNA expression. Trypsin converted latent MMP-2 and MMP-9 into their active forms of MMP-2 (66 kDa) and MMP-9 (82 kDa) within 24 hours. This conversion was significantly inhibited by 25(OH)D (100 nM) and $1,25(OH)_2D$ (100 nM). The expression of MMP-9 mRNA was also significantly inhibited by 25(OH)D and $1,25(OH)_2D$. Conclusion: Vitamin D, 25(OH)D, and $1,25(OH)_2D$ play a role in regulating human lung fibroblast functions in wound repair and tissue remodeling through not only inhibiting IL-$1{\beta}$ stimulated MMP-9 production and conversion to its active form but also inhibiting IL-$1{\beta}$ inhibition on TIMP-1 and TIMP-2 production.

• Nutrition Research and Practice
• /
• v.7 no.6
• /
• pp.495-502
• /
• 2013

Recent studies suggest that vitamin D deficiency and cardiometabolic disorders are becoming increasingly more prevalent across multiple populations. However, there is a lack of comprehensive data for Korean adults. We investigated the vitamin D status, the prevalence of vitamin D deficiency and its association with metabolic syndrome (MS) risk in Korean adults aged 20 years or older. The study subjects (n = 18,305) were individuals who participated in the Korean National Health Examination and Nutrition Survey (KNHANES) in 2008-2010. Vitamin D status (25-hydroxyvitamin D [25(OH)D]) was categorized as < 20, 21-29, and ${\geq}$ 30 ng/mL, which are the cut-off points for deficiency, insufficiency and normal limits. A wide variety of cardiometabolic risk factors were compared according to the vitamin D status. Vitamin D deficiency was found in 53.9% of men and 70.5% of women. Mean BMI, systolic BP, HbA1c and low density lipoprotein cholesterol (LDL-C) were highest in the vitamin D deficiency group in both genders. Further, the MS was most prevalent in the vitamin D deficiency group in both genders (12.3%, P = 0.002 in men and 9.2%, P < 0.001 in women). Compared to the vitamin D normal group, the adjusted odds ratio (ORs) (95% confidence interval [95% CI]) for MS in the vitamin D deficiency group were 1.46 (1.05-2.02) in men and 1.60 (1.21-2.11) in women, after adjusting for confounding variables. In conclusion, Vitamin D deficiency is a very common health problem in Korean adults and is independently associated with the increasing risk of MS.

• Clinical and Experimental Pediatrics
• /
• v.53 no.2
• /
• pp.152-157
• /
• 2010

Purpose : Vitamin D deficiency rickets is a significant public health problem that results from insufficient exposure to sunlight and inadequate vitamin D supplementation. The purpose of this study is to identify the clinical characteristics of vitamin D deficiency rickets in infants. Methods : Data of 35 infants diagnosed as vitamin D deficiency rickets at Sanggye-Paik Hospital, Seoul, Korea, from March 2007 to May 2009 were reviewed. Children with plasma 25-hydroxyvitamin D levels <15 ng/mL and 15-30 ng/mL were considered to have vitamin D deficiency and vitamin D insufficiency, respectively. Results : Thirty-five infants (22 boys, 13 girls) were diagnosed with rickets. Mean age at diagnosis was $7.4{\pm}7.1$ months (range: 0.1-29.8 months). Eighteen infants (51%) were vitamin D deficient and seventeen infants (49%) were insufficient. Twenty-eight of all (80%) diagnosed as subclinical rickets. Twenty-nine infants (83%) were below the age of 12months. Twenty infants (57%) had breastfed and ten infants (29%) had iron deficiency anemia. Nine of breastfed infants (45%) were vitamin D deficient and ten of their mothers were vitamin D insufficient. Overall, radiographic evidence of rickets was present in 93% of the cases. Radiographic sign of rickets was evident even in vitamin D insufficient state. Conclusion : It is important for the clinician to screen for subclinical vitamin D deficiency rickets in inadequately supplemented infants by pairing 25-hydroxyvitamin D levels with wrist radiographs. A nationwide epidemiological study of vitamin D deficiency rickets must be conducted and evidence-based national guidelines must be defined to prevent rickets.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.1
• /
• pp.133-137
• /
• 2010

Purpose: The main function of vitamin D is the mineralization of the brain by increase of calcium and phosphorus, in case it is insufficient in children, lime deposition on cartilage cannot occur so it leads to rachitis, and in adults, it leads to osteomalacia or osteoporosis. It is also strongly believed in the academic world that vitamin D can restrict the growth of cancer cells and prevent heart diseases, which is also somewhat proven in epidemiological researches. While the right density of vitamin D is still being studied, 20-32 ng/mL is believed to be the most ideal density. Therefore, I wanted analyze how much density of 25-Hydroxyvitamin D3 that Koreans possess. Materials and Methods: From February 20th, 2008 to April 21st, 2009, the collection of 2800 serums, from medical examination treated subjects by Neodin Medical Institute, have been tested. The targets were tested by 25-Hydroxyvitamin D (125I Kit: Diasorin, USA), and were analyzed by dividing into many different categories (gender, age, season, region). Results: The average density of male were 20 ng/mL, female 17.08 ng/mL. Per age groups, the density of males were as follows: 10~20-18 ng/mL, 21~30-17 ng/mL, 31~40-19 ng/mL, 41~50-21 ng/mL, 51~60-22 ng/mL, 61~70-22 ng/mL, 71~80-22 ng/mL and 81~90-19.9 ng/mL. Average density of females per age groups, were as follows: 10~20-16 ng/mL, 20~30-15.26 ng/mL, 30~40-16 ng/mL, 40~50-17 ng/mL, 50~60-19 ng/mL, 60~70-19 ng/mL, 70~80-19 ng/mL, and 80~90-17 ng/mL. Per seasons, From December to May, the subjects showed the density of 15.97 ng/mL, while from June to November, it showed 21.60 ng/mL. On density of males from January to April regionally, Seoul+Gyeonggi-Do-15.52 ng/mL, Gangwon-Do-15.33 ng/mL, Choongchung-Do-18.03 ng/mL, Jeonla-Do-18.68 ng/mL, Gyungsang-Do-18.76 ng/mL and Cheju Do-21.23 ng/mL. Conclusions: The vitamin D of Koreans is has been insufficient compared to the suggested amount. Ultraviolet rays, which is the main source of vitamin D is critical, therefore it is suggested that more outdoor activities can definitely help.

• Journal of Nutrition and Health
• /
• v.31 no.1
• /
• pp.46-61
• /
• 1998

This study was carried out to evaluate the effects of vitamin D nutritional status on bone mineral density of adults (21-49 years). To attain the aim, we measured bone mineral density (BMD) of the subjects at distal radius by single-photon absorptiometry (SPA). Serum level of 25-hydroxyvitamin D(25-(OH)D) , known to be the best indicator of indicator of vitamin D status in humans was analyzed . The factors affecting this vitamin D level were also investigated in autumn in 122 young adults. Serum level of 25-(OH)D was measured by high pressure liquid chromatography(HPLC) and biochemical variables, general health status, time spent outdoors, and dietary intakes of the subjects. BMD of the male subjects was significantly greater than that of female subjects. Weight, activity and total energy expediture (TEE) showed a positive correlation with distal BMD. The mean level of serum 25-(OH)D was 24.4$\pm$11.0 ng./ml and by sex, 26.0$\pm$6.8ng/ml for males and 23.3$\pm$12.3ng/ml for females , the level was significantly higher in male (p<0.01). there was significant correlation between BMD at distal-radius and s-25(OH)D levels (p<0.001). The serum level fo parathyroid hormone (PTH) showed a negative correlation with BMD(p<0.05), with the more obvious correlation in females. Vitamin D intake was estimated to be 3.75$\pm$2.19ug/day in average. Among the nutrients studied, protein ,fat, calcium , and vitamin D intake were positively correlated with distal BMD. When food frequencies were concerned , milk and dairy products showed a significant positive correlation with the BMD level, and driedfoods, eggs , fats and oils, and cereals also showed a positive correlation. Time spent outdoors was estimated to be about 70 minutes in average and positively correlated with the distal BMD level(p<0.01). During the day, the specific time between 12 :00pm and 2:00pm showed the most significant correlation with BMD (p<0.001). Multiple regression analysis with the variables showed that distal BMD could be fit 31.9% by the time spent outdoors a day, intake of Ca and vitamin D, and TEE. The standardized estimates were 0.344 for vitamin D intake, 0.284 for Ca intake 0.179 for the time spent outdoors a day and 0.273 for TEE. For males, s-25*OH)D level, TEE and time spent outdoors during a day showed a significant correlation. For females, intake of Ca and vitamin D could fit about 27.1% of the distal BMD.

• Journal of Preventive Medicine and Public Health
• /
• v.50 no.4
• /
• pp.278-281
• /
• 2017

Since 2006, type 1 diabetes in Finland has plateaued and then decreased after the authorities' decision to fortify dietary milk products with cholecalciferol. The role of vitamin D in innate and adaptive immunity is critical. A statistical error in the estimation of the recommended dietary allowance (RDA) for vitamin D was recently discovered; in a correct analysis of the data used by the Institute of Medicine, it was found that 8895 IU/d was needed for 97.5% of individuals to achieve values ${\geq}50nmol/L$. Another study confirmed that 6201 IU/d was needed to achieve 75 nmol/L and 9122 IU/d was needed to reach 100 nmol/L. The largest meta-analysis ever conducted of studies published between 1966 and 2013 showed that 25-hydroxyvitamin D levels <75 nmol/L may be too low for safety and associated with higher all-cause mortality, demolishing the previously presumed U-shape curve of mortality associated with vitamin D levels. Since all-disease mortality is reduced to 1.0 with serum vitamin D levels ${\geq}100nmol/L$, we call public health authorities to consider designating as the RDA at least three-fourths of the levels proposed by the Endocrine Society Expert Committee as safe upper tolerable daily intake doses. This could lead to a recommendation of 1000 IU for children <1 year on enriched formula and 1500 IU for breastfed children older than 6 months, 3000 IU for children >1 year of age, and around 8000 IU for young adults and thereafter. Actions are urgently needed to protect the global population from vitamin D deficiency.

• Journal of Preventive Medicine and Public Health
• /
• v.50 no.6
• /
• pp.369-376
• /
• 2017

Objectives: Dry eye disease (DED) is an increasingly important public health problem in Korea. Previous studies conducted in Korea have reported inconsistent results regarding the protective effects of vitamin D on DED, and these discrepancies may be related to the relatively simple questionnaire that has been used. Thus, we evaluated the association of serum vitamin D levels with DED using the ocular surface disease index (OSDI). Methods: The present study evaluated data from participants in the Study Group for Environmental Eye Disease (2014-2015). This group included data from 752 participants, and data from 740 participants (253 men and 487 women) were analyzed in the present study. DED severity was evaluated using the OSDI. Results: Higher serum vitamin D levels were associated with a non-significantly reduced risk of DED in the crude analysis (odds ratio [OR], 0.991; 95% confidence interval [CI], 0.971 to 1.011) and in the adjusted analysis (OR, 0.988; 95% CI, 0.966 to 1.010). In the crude analysis of no/mild DED vs. moderate/severe DED, men exhibited a decreased risk with increasing serum vitamin D levels (OR, 0.999; 95% CI, 0.950 to 1.051), while women exhibited an increased risk (OR, 1.003; 95% CI, 0.979 to 1.027). In these analyses, we found no significant associations. Conclusions: The findings of the present study support previous reports that serum vitamin D levels are not associated with DED.

• Korean Journal of Veterinary Service
• /
• v.40 no.4
• /
• pp.281-285
• /
• 2017

Six to seven-month-old 10 beef calves in 140-head beef cattle farm in Gimpo-si, Gyeonggi-do were suffered from ataxia and astasia. Two of them were submitted to Animal and Plant Quarantine Agency for diagnosis in July 9, 2015. At necropsy, the radius and tibia of both calves showed irregular thickening and hemorrhage of the physis in addition to hemorrhage and disruption of trabeculae in metaphysis. Histopathologically the physis showed irregular tongues of cartilage remaining the metaphysis. Disorganization, hemorrhage and fibrosis were observed in metaphyseal and epiphyseal bones. The serum 25-hydroxyvitamin $D_3$ ($D_3$) and calcium levels were lower than normal range. In addition, the serum $D_3$ levels in the other 9 calves of the same farm were lower than normal levels. Based on the pathological examination and serum chemistry measurements, we diagnosed this case as rickets caused by vitamin D deficiency in calves.

• Journal of Preventive Medicine and Public Health
• /
• v.48 no.5
• /
• pp.249-256
• /
• 2015

Objectives: Epidemiological studies have reported that vitamin D deficiency is associated with inflammatory disease. Smoking is a well-known risk factor for inflammation. However, few studies have investigated the interactive effect of vitamin D deficiency and smoking on inflammation. This study aims to investigate the interaction of vitamin D and smoking with inflammatory markers in the urban elderly. Methods: We used data from the Korean Elderly Environmental Panel Study, which began in August 2008 and ended in August 2010, and included 560 Koreans ${\geq}60$ years old living in Seoul. Data was collected via questionnaires that included items about smoking status at the first visit. Vitamin D levels, high-sensitivity C-reactive protein (hs-CRP), and white blood cell (WBC) counts were repeatedly measured up to three times. Results: The association of vitamin D and hs-CRP was significant after adjusting for known confounders (${\beta}=-0.080$, p=0.041). After separate analysis by smoking status, the association of vitamin D deficiency and hs-CRP in smokers was stronger than that in nonsmokers (smokers: ${\beta}=-0.375$, p=0.013; non-smokers: ${\beta}=-0.060$, p=0.150). Smoking status was an effect modifier that changed the association between vitamin D deficiency and hs-CRP (interaction estimate: ${\beta}=-0.254$, p=0.032). Vitamin D was not significantly associated with WBC count (${\beta}=0.003$, p=0.805). Conclusions: Vitamin D deficiency was associated with hs-CRP in the urban elderly. Smoking status was an effect modifier of this association. Vitamin D deficiency was not significantly associated with WBC count.