• 한국식품과학회지
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• 제37권6호
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• pp.861-865
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• 2005

본 연구는 일반적으로 사용되고 있는 vitamin C 분석방법인 2,4-dinitrophenylhydrazine(DNP), indophenol, 그리고 HPLC법을 이용하여 시판중인 다양한 제품을 이용하여 보존조건($10^{\circ}C,\;20^{\circ}C$)에 따른 vitamin C 함량을 세 가지 방법으로 비교 검토함으로서 가장 이상적인 분석방법을 조사하였다. $10^{\circ}C$ 보존시 요쿠르트 A 제품에서의 vitamin C 변화 추세를 살펴보면, DNP법은 초기와 말기 TAA 함량이 각자 26.7과 22.8mg/100mL로 측정되었으나, 저장 3일째와 10일째에 오히려 증가하는 현상을 보였으며, 또만 indophenol법은 초기와 말기에 각각 28.6과 9.5mg/100mL로, HPLC법은 30.5와 14.6mg/100mL로 확인되었다. 그리고 본 실험에서는 indophenol법과 HPLC법은 일정한 감소 추세를 보였다. 따라서, 가장 이상적인 vitamin C 분석 방법은 HPLC법이며, 저장 초기에 간단하게 vitamin C 함량을 측정할 경우에는 indophenol법을 이용하여도 신뢰할 수 있는 결과를 얻을 수 있는 것으로 사료된다.

• Clinical Nutrition Research
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• 제12권3호
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• pp.184-198
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• 2023

Early prevention of sarcopenia can be an important strategy for muscle maintenance, but most studies target subjects at slightly pre-sarcopenic state. Our previous paper describes the effect of protein supplements rich in leucine and vitamin D on muscle condition, and in this paper, we performed a sub-analysis to evaluate who benefitted the most in terms of improvement in muscle health. A 12-week randomized clinical trial of 120 healthy adults (aged 50 to 80) assigned to an intervention group (n = 60) or control group (n = 60) were analyzed. Subjects in the intervention group received, twice per day, a protein supplement containing (per serving) 800 IU of vitamin D, 20 g of protein (3 g of total leucine), 300 mg of calcium, 1.1 g of fat, and 2.5 g of carbohydrate. The subjects were classified into 'insufficient' and 'sufficient' groups at 25-hydroxyvitamin D (25[OH]D) value of 30 ng/mL. The skeletal muscle mass index normalized to the square of the skeletal muscle mass (SMM) height (kg/m²) increased significantly in the 'insufficient group' difference value of change between weeks 0 and 12 (Δ1.07 ± 2.20; p = 0.037). The SMM normalized by body weight (kg/kg, %) was higher, but not significantly, in the insufficient group (Δ0.38 ± 0.69; p = 0.050). For people with insufficient (serum 25[OH]D), supplemental intake of protein and vitamin D, calcium, and leucine and adequate energy intake increases muscle mass in middle-aged and older adults and would be likely to exert a beneficial effect on muscle health.

• Biomolecules & Therapeutics
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• 제17권2호
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• pp.125-132
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• 2009

Calbindin-$D_{9k}$ (CaBP-9k), a cytosolic calcium-binding protein, is expressed in a variety of tissues, i.e., the duodenum, uterus, placenta, kidney and pituitary gland. Duodenal CaBP-9k is involved in intestinal calcium absorption, and is regulated at transcriptional and post-transcriptional levels by 1,25-dihydroxyvitamin D3, the hormonal form of vitamin D, and glucocorticoids (GCs). Uterine CaBP-9k has been implicated in the regulation of myometrial action(s) through modulation of intracellular calcium, and steroid hormones appear to be the main regulators in its uterine and placental regulation. Because phenotypes of CaBP-9k-null mice appear to be normal, other calcium-transporter genes may compensate for its gene deletion and physiological function in knockout mice. Previous studies indicate that CaBP-9k may be controlled in a tissue-specific fashion. In this review, we summarize the current information on calcium homeostasis related to CaBP-9k gene regulation by GCs, vitamin D and its receptors, and its molecular regulatory mechanism. In addition, we present related data from our current research.

• 치위생과학회지
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• 제17권3호
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• pp.233-241
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• 2017

This study identified an effective control method for periodontitis by investigating the association between blood levels of vitamin D and periodontitis in Korean elderly based on raw data from the fifth Korea National Health & Nutrition Examination Survey of 2010 (KNHANES). In this study, 1,021 adults over 65 years of age were evaluated based on data from the KNHANES. Periodontal disease was assessed using community periodontal index (CPI), with CPI codes ${\geq}3$ defined as periodontitis. Blood levels of vitamin D were measured from blood samples and divided into four groups (first quartile: ${\leq}13.23ng/ml$, second quartile: 13.24~16.95 ng/ml, third quartile: 16.96~21.58 ng/ml), and fourth quartile >21.59 ng/ml). Using multiple logistic regression analyses, the variables were adjusted for general characteristics, oral health-related characteristics, health-related characteristics, and bone mineral density. The statistical analysis was performed using the SAS (ver. 9.2). The results of this study are as follows: the prevalence of periodontitis was 42.6% in Korean elderly. After adjusting for general, oral health-related, and health-related, the risk of periodontitis in the first quartile group was 1.74 times (95% confidence interval [CI], 1.02~2.98) higher than that of the fourth quartile group (p=0.041). After adjusting for general, oral health-related, and health-related characteristics as well as bone mineral density, the risk of periodontitis in the first quartile group was 1.73 times (95% CI, 1.02~2.96) higher than that of the four quartile group (p=0.042). There was a significant relationship between blood vitamin D level and periodontitis in Korean elderly. For the prevention of periodontitis, factors related to vitamin D should be considered along with other risk factors.

• Journal of Preventive Medicine and Public Health
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• 제50권6호
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• pp.369-376
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• 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.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.52-53
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• 2001

In order for vitamin D to be active, it needs to get metabolized to 1, 25 (OH)$_2$D3. This active metabolite of vitamin D induces epithelial cell differentiation and is antiproliferative. However, at the efficacious concentration, the natural ligand for VDR is hypercalcemic and toxic to cells. Therefore, numerous analogs have been synthesized with the hope of generating a compound that retains vitamin D activity and is non-toxic.(omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Effects of Edible Phytochemicals and Their Synthetic Derivatives on Carcinogenesis and Mutagenesis
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• pp.9-10
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• 2001

In order for vitamin D to be active, it needs to get metabolized to 1, 25 (OH)$_2$D3. This active metabolite of vitamin D induces epithelial cell differentiation and is antiproliferative. However, at the efficacious concentration, the natural ligand for VDR is hypercalcemic and toxic to cells. Therefore, numerous analogs have been synthesized with the hope of generating a compound that retains vitamin D activity and is non-toxic.(omitted)

• 대한임상검사과학회지
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• 제52권2호
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• pp.91-97
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• 2020

비타민 D 검사의 표준화는 전 세계적으로 계속되고 있으며, 결과의 정확성을 향상시키기 위해 많은 노력을 기울였다. 본 연구의 목적은 외부 품질 평가(EQA) 프로그램을 이용하여 비타민 D 검사의 시그마 메트릭스 값을 분석하는 것이다. 시그마 메트릭스는 검사기관에서 수행한 정량적 시험에 사용되며, 분석결과는 품질 측면에서 객관적으로 시각화할 수 있다. 이 분석은 약 300개의 검사기관이 참여한 가운데, CAP의 외부정도관리 프로그램인 2019년 정확도 기반 비타민 D (ABVD) 조사 결과를 이용하여 수행하였다. CDC 표준검사기관에서 얻어진 표준 값 6개의 서로 다른 농도에서는 시그마 메트릭 값이 각각 1.00, 1.85, 2.42, 1.01, 1.54 및 0.78로 분석되었다. 평균 1.43 시그마 메트릭 값을 보여주었다. 특히, 검체 ABVD-16, 17의 결과값에서의 양성 편향은 비타민 D 측정을 위한 표준검사법인 액체크로마토그래피 탠덤 질량 분석(LC-MS/MS)에 대해서만 나타났다. 차이의 원인은 다양한 비타민 D 대사산물에 대한 다양한 교차 반응으로 설명된다. 검사 기관은 전반적인 성능을 개선해야 한다.

• Journal of Applied Biological Chemistry
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• 제58권1호
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• pp.25-29
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• 2015

The determination of the optimum conditions for the conversion of ergosterol to vitamin $D_2$ in shitake mushrooms (Lentinula edodes) was studied using response surface methodology (RSM). The effects of the three main variables ambient temperature ($20-40^{\circ}C$), exposure time (60-180 min), and irradiation intensity ($0.6-1.8W/m^2$) were investigated. According to the RSM ridge analysis, the optimum conditions were as follows: ambient temperature of $34.2^{\circ}C$, exposure time of 175.6 min, and irradiation intensity of $1.41W/m^2$. Under these optimum conditions, the maximum vitamin $D_2$ content of $117.93{\mu}g/g$ in shitake mushrooms was obtained, which agreed fairly well with the predicted value of $122.60{\mu}g/g$.

• Journal of Community Nutrition
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• 제7권2호
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• pp.79-84
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• 2005

A vitamin B-6 (B-6) intake higher than the current Recommended Dietary Allowance (RDA) has been found to provide an improvement in immune system. Seven premenopausal women consumed their usual diet with the exception of foods relatively high in vitamin B-6 for a total of 27 d. After 7 d, all subjects received a multivitamin supplement containing 2mg B-6 and 4 subjects were given an additional 50mg of B-6 supplement for 20 d. Lymphocyte response to phytohemagglutinin (PHA) was measured before and after the supplementation. To determine the effect of different forms of B-6 on lymphocyte proliferation, cell culture media supplemented with pyridoxal (PL) and PLP, as well as B-6 free media, were tested. A 50mg B-6 supplement significantly increased vitamin B-6 status. There was no further enhancement on lymphocyte proliferation when subjects were taking an additional 50mg of vitamin B-6 supplement. In general, lymphocyte proliferation in media with either PLP or PL did not show any prominent difference. These [m-dings suggest that there may be no further benefits of a B-6 dose beyond twice that of the current RDA on lymphocyte proliferation. Further studies are necessary to examine the effect of the B-6 intake level on activities of enzymes involved in cellular B-6 metabolism in lymphocytes to provide substantial insight into the mechanisms underlying the role of B-6 in the lymphocyte proliferation.