• Korean journal of food and cookery science
• /
• v.23 no.1 s.97
• /
• pp.99-106
• /
• 2007

This study investigated the effect of UV-B irradiation on the quality of Pleurotus ostreatus. The changes of vitamin $D_2$ contents, color value and flavor pattern in mushrooms were analyzed by high-performance liquid chromatography (HPLC), chromameter and gas chromatography - surface acoustic wave (GC-SAW) electronic nose. By exposure to UV-B irradiation (0 kj/m$^2$, 10 kj/m$^2$, 20 kj/m$^2$), vitamin $D_2$ content increased from 0 (control) to 48.50 g/g (DM: dry matter, 10 kj/m$^2$) and 61.58 g/g (DM, 20 kj/m$^2$). Although there was no significant difference in L, a, b values among the three groups, flavor changes were detected by GC-SAW electronic nose. The number of peaks increased from 10 in the control group (0 kj/m$^2$), to 14 and 15 for the 10 kj/m$^2$ and 20 kj/m$^2$ groups, respectively. Nevertheless, the changes of flavor pattern were not detrimental to the mushroom quality. These results suggested that UV-B irradiation is an effective method to increase the vitamin $D_2$ content without degrading the quality.

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

• Korean Journal of Environmental Agriculture
• /
• v.30 no.2
• /
• pp.196-201
• /
• 2011

BACKGROUND: Bioavailability enhancement by solubilization of lipophilic drugs in nano-emulsion has been reported and it may be useful in pharmaceutical and nutraceutical products. This study was performed to compare in vivo bioavailability of nano-emulsion formulation with that of the general product as control. METHODS AND RESULTS: The pharmacokinetics assessment of Vitamin A, D and E complex of nanoemulsion formulation (LaVita), in comparison to the general product, was performed in the male rat plasma by a single oral dose at 20 mL/kg body weight (n=3/group). For nano-emulsion formulation (LaVita), $C_{max}$ of vitamin A and E in plasma were much higher and the area under the curve (AUC) of vitamin A, D and E were 14-63% higher, and the half-life of vitamin E was 2-fold longer than the general product. According to statistical analysis, each $C_{max}$ of vitamin A, D & E was significantly higher (p<0.01, 0.05 and 0.01, respectively) than that of general product. Half-life of vitamin A was significantly higher (p<0.01) and AUC of vitamin A and D were also significantly higher than the general product. CONCLUSION(s): Considering significant increment of $C_{max}$ and AUC, LaVita made of nano-emulsion could be more effective the absorption rate and extent for bioavailability of vitamin A, D & E than those of general product.

• The Korean Journal of Physiology and Pharmacology
• /
• v.18 no.5
• /
• pp.397-402
• /
• 2014

Microglia are activated by inflammatory and pathophysiological stimuli in neurodegenerative diseases, and activated microglia induce neuronal damage by releasing cytotoxic factors like nitric oxide (NO). Activated microglia synthesize a significant amount of vitamin $D_3$ in the rat brain, and vitamin $D_3$ has an inhibitory effect on activated microglia. To investigate the possible role of vitamin $D_3$ as a negative regulator of activated microglia, we examined the effect of 25-hydroxyvitamin $D_3$ on NO production of lipopolysaccharide (LPS)-stimulated microglia. Treatment with LPS increased the production of NO in primary cultured and BV2 microglial cells. Treatment with 25-hydroxyvitamin $D_3$ inhibited the generation of NO in LPS-activated primary microglia and BV2 cells. In addition to NO production, expression of 1-${\alpha}$-hydroxylase and the vitamin D receptor (VDR) was also upregulated in LPS-stimulated primary and BV2 microglia. When BV2 cells were transfected with 1-${\alpha}$-hydroxylase siRNA or VDR siRNA, the inhibitory effect of 25-hydroxyvitamin $D_3$ on activated BV2 cells was suppressed. 25-Hydroxyvitamin $D_3$ also inhibited the increased phosphorylation of p38 seen in LPS-activated BV2 cells, and this inhibition was blocked by VDR siRNA. The present study shows that 25-hydroxyvitamin $D_3$ inhibits NO production in LPS-activated microglia through the mediation of LPS-induced 1-${\alpha}$-hydroxylase. This study also shows that the inhibitory effect of 25-hydroxyvitamin $D_3$ on NO production might be exerted by inhibiting LPS-induced phosphorylation of p38 through the mediation of VDR signaling. These results suggest that vitamin $D_3$ might have an important role in the negative regulation of microglial activation.

• The korean journal of orthodontics
• /
• v.29 no.3 s.74
• /
• pp.383-397
• /
• 1999

Bone is a dynamic tissue which is constantly remodelled by subsequent cycles of bone resorption and formation. Glucocorticoid and vitamine $D_3$ are known as regulating substances in bone metabolism. In vitro experiments using bone tissue, it was suggested that glucocorticoid inhibits bone resorption, whereas the effect of glucocorticoid on bone formation are complex- increasing or decreasing effect. The active form of vitamin $D_3$, 1,25-dihydroxycholecalciferol[1.25-$(OH)_2D_3$], has been reported to stimulate osteoblastic activities including the production of ALP, type I collagen, and osteoclacin. The purpose of this study was to evaluate the effect of admixture of vitamin $D_3$ and dexamethasone, one of glucocorticoids, on osteoblastic cell line(MC3T3-E1). Alkaline phosphatase(ALP) and MTT assay were conducted in the cultivated cells with 1, 10, 100nM/ml of 1,25-$(OH)_2D_3$ and/or 10nM/ml, 100nM/ml, $1{\mu}M/ml$ of dexamethasone. The observed results were as follows. 1. The activity of osteoblastic cells with $1{\mu}M/ml$ of dexamethasone was significantly increased at 1-day cultivation with comparison to control group, but was decreased afterwards. But the activity of ALP was greatest in $1{\mu}M/ml$ of dexamethasone and increased with time lapsed. 2. The activity of osteoblastic cells with vitamin $D_3$ was significantly increased dose-dependently at 1-day cultivation, but was significantly decreased in l00nM/.ml at 2-day cultivation, and was a little increased again at 3-day cultivation. The activity of ALP was increased in 10nM/ml or 100nM/ml at 2-day or 3-day cultivation, and was greatest in 100nM/ml at 3-day cultivation. 3. In case of admixture of dexamethasone and vitamin $D_3$, the cellular activity was decreased in any concentration of vitamin $D_3$ at 2-day cultivation, but was increased again at 3-day cultivation, which was greater than that in control or dexamethasone only group. The activity of ALP was decreased at 1-day cultivation, but was increased in the admixture of 10nM/ml or 100nM/ml of dexamethasone with 100nM/ml of vitamin $D_3$ at 2-day cultivation, and was again decreased at 3-day cultivation.

• Journal of Nutrition and Health
• /
• v.49 no.1
• /
• pp.28-35
• /
• 2016

Purpose: Vitamin D status is associated with several chronic diseases related to obesity. In this study, we evaluate the nutritional status of vitamin D and its relation to obesity indices in Korean women. Methods: A total of 156 healthy women participated. Vitamin D status (serum $25-OH-vitamin\;D_3$ level) and obesity indices (body mass index, body fat mass, waisthip ratio, and body fat percentage etc.) and serum lipid profiles and serum adipokine (leptin and adiponectin) levels were analyzed. Results: The $25(OH)D_3$ level showed an extremely skewed distribution from 4.1 ng/ml to 24.4 ng/ml and mean $25(OH)D_3$ level was $9.0{\pm}4.0ng/ml$. With cut-off level for vitamin D deficiency (< 12.0 ng/ml), insufficiency (12-19.9 ng/ml) and sufficiency (${\geq}20ng/ml$), 77.6%, 19.2%, and 3.2% of subjects showed vitamin D deficiency, insufficiency, and sufficiency status, respectively. The $25(OH)D_3$ level showed positive correlation with weight (r = 0.2461, p < 0.01), body mass index (r = 0.2913, p < 0.001), body fat contents (r = 0.1691, p < 0.05), fat free mass (r = 0.2330, p < 0.01), and waist hip ratio (r = 0.1749, p < 0.05) after adjusted by age. The $25(OH)D_3$ level showed no significant correlation with serum lipid profiles and adipokine levels. Conclusion: Most subjects (76.6%) in this study, who had a vitamin D deficient status and serum $25(OH)D_3$ level, showed positive correlation with several obesity indices, however further research based on a large Korean population is needed to confirm the relationship.

• Nutritional Sciences
• /
• v.8 no.2
• /
• pp.111-117
• /
• 2005

It has been more than three decades since the first assay assessing circulating 25 (OH)D in human subjects was performed That publication as well as several that followed it defined 'normal' nutritional vitamin D status in human populations. Recently, the wisdom by which 'normal' circulating 25 (OH)D levels in human subjects were assigned in the past has come under question. It appears that sampling human subjects, who appear to be free from disease, and assessing 'normal' circulating 25 (OH)D levels by plotting a Gaussian distribution is grossly inaccurate. There are many reasons why this method is inaccurate, including race, lifestyle habits, sunscreen usage, age, latitude, and inappropriately low dietary recommendations for vitamin D. For instance, a 400 IU/day. AI for vitamin D is insignificant when one considers that a 10-15 minute whole body exposure to peak summer sun will generate and release up to 20,000 IU vitamin $D_3$ into the circulation. Recent studies, which orally administered up to 10,000 IU/day vitamin $D_3$ to human subjects for several months, have successfully elevated circulating 25 (OH)D levels to those observed in individuals from sun-rich environments. Further, we are now able to accurately assess sufficient circulating 25 (OH)D levels utilizing specific biomarkers instead of guessing what an adequate level is. These biomarkers include intact parathyroid hormone (PTH), calcium absorption, bone mineral density (BMD), insulin resistance and pancreatic beta cell function. Using the data from these biomarkers, vitamin D deficiency should be defined as circulating levels of 25 (OH)D$\leq$30 ng/mL. In certain cases, such as pregnancy and lactation, significantly higher circulating 25 (OH)D levels would almost certainly be beneficial to both the mother and recipient fetus/infant.

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

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.4
• /
• pp.563-567
• /
• 2006

Two experiments were conducted to compare the effect of various vitamins on performance and digestibility in growing pigs. In experiment 1, a total of 54 pigs ($L{\times}Y{\times}D$, $42.73{\pm}2.40kg$) were assigned to three treatments in a randomized complete block design with three replicates (6 pigs/pen) for 40 days. The three dietary treatments were: 100% fat-soluble vitamins (FSV) and water-soluble vitamins (WSV); 150% FSV and 100% WSV of NRC (1998); and 100% FSV and 150% WSV of NRC (1998). In experiment 2, a total of 180 pigs ($L{\times}Y{\times}D$, $28.20{\pm}3.05 kg$) were assigned to four treatments in a completely randomized design with three replicates for four weeks (15 pigs/pen). The four dietary treatments were, 150% vitamin A and 100% other vitamins, 150% vitamin D and 100% other vitamins, 150% vitamin E and 100% other vitamins, and 150% vitamin K and 100% other vitamins. In experiment 1, there were significant differences in growth performance and digestibility of nutrients among the treatments. The ADG, ADFI and FCR of pigs fed 150% FSV diet were better (p<0.05) than those fed the control diet. However, there were no differences (p>0.05) in ADG, ADFI and FCR between pigs fed the control and 150% WSV diets. Digestibilities of dry matter, gross energy and calcium were improved in 150% FSV treatment group compared with control (p<0.05). However, the improvement was similar when compared with 150% WSV except for Ca. In experiment 2, there were no differences (p>0.05) in ADG, ADFI and FCR and nutrient digestibility between the fat-soluble vitamin treatments when fed at the 150% level. In conclusion, growing pigs were more responsive to additional fat-soluble vitamin supplements over the requirements suggested by NRC (1998) than to water-soluble vitamin supplements as measured by growth performance and digestibility of nutrients.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.109-121
• /
• 2023

This study was conducted to evaluate vitamin D intake of Koreans in a total diet study (TDS) and to determine the effect of irradiation on vitamin D synthesis in mushrooms. For analysis, sample were saponified and extracted with hexane, and vitamin D was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on the validation results, the recovery of the National Institute of Standards and Technology (NIST) standard reference sample (SRM) 1849a was 96.7% and the z-score of -1.6 was obtained by the Food Analysis Performance Assessment Scheme (FAPAS) proficiency test (PT) 21115. Vitamin D₂ was not detected in any samples, and the highest level of vitamin D₃ was detected in mackerel and anchovies ranging from 24.2 to 120.2 ㎍/kg. The mean daily intake of vitamin D was 0.99 ㎍/day, as estimated from the vitamin D contents of the analyzed foods and their corresponding intake. The adequate intake (AI) of vitamin D based on the Dietary reference intakes for Koreans provided by the Ministry of Health and Welfare is 5-15 ㎍/day for Koreans aged 6 to 75 years. Compared with this AI, vitamin D intake of Koreans estimated in this study was inadequate. For that, the increased vitamin D content in ultraviolet (UV)/sun light irradiated mushrooms warrants further research to increase vitamin D intake of Koreans through diet.