• Korean Journal of Poultry Science
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• v.22 no.2
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• pp.117-128
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• 1995

Vitarnin A levels of egg yolk from hens fed diets supplemented with vitamin A increased slowly up to Week 4, while the values rapidly increased thereafter. The highest value(360% of initial value) was observed at Week 8 in birds fed 64,000 IU of vitamin A/kg diet. On the other hand, the contents of vitamin E in egg yolk rapidly increased in the first 2 weeks of the experiment and then stabilized up to Week 8. However, the efficiency of egg transfer decreased(P<0.05) as dietary vitamins A and E levels increased. It took at least 4 weeks for the increased levels of vitamin A and E in eggs from hens fed diets supplemented with each vitamin to recover the normal levels. Vitamin E levels of egg yolk in hens fed the vitamin A supplemented diets decreased as dietary vitamin A level increased (P<0.05). On the other hand, a slightly reduced levels of vitamin A levels of egg yolks from hens fed the vitamin E supplemented diet for 4 weeks of experiment was recovered back to control level at Week 8(P<0.05). Supplemental vitamin A markedly decreased the yolk deposition of vitamin F when two vitamins were supplemented simultaneously. The yolk deposition of vitamin A decreased as high level of vitamin B was supplemented, suggesting an antagonistic interactions between the two vitamins.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.2
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• pp.207-217
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• 2021

Purpose: This study aimed to investigate the seasonal changes in vitamin D levels in a healthy pediatric population living in mid-latitude East Asian urban areas. Methods: A pediatric population was selected from single secondary hospital visitors. Clinical data and serum vitamin D levels were collected retrospectively. Statistical analyses were performed based on the month of the blood sampling date, subject age, and vitamin D supplementation history. The data were categorized into three subgroups based on serum vitamin D levels-adequate (≥30 ng/mL), insufficient (20-29 ng/mL), and deficient (<20 ng/mL). Results: Of the 481 patients, 172 had vitamin D supplementation history. More than 70% of the total study population had inadequate vitamin D levels (<30 ng/mL). The non-supplemented group and the supplemented group showed significantly uneven monthly distribution of the adequate, insufficient, and deficient subgroups. Only the non-supplemented group showed significantly different average vitamin D levels in the summer months compared to the winter months. In the non-supplemented group, vitamin D levels were the lowest in March, the highest in August and September. Significant relevance was noted between vitamin D supplementation status and vitamin D serum level in February and March. There was no significant difference between different age groups in terms of the distribution of vitamin D levels. Conclusion: Currently-widespread vitamin D replacement methods seem to have some effect on increasing the overall serum vitamin D levels, specifically during late winter when natural serum vitamin D levels plunge. However, they are unable to fully compensate the seasonal fluctuation.

• Food Science and Preservation
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• v.12 no.4
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• pp.411-416
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• 2005

Vitamin U(S-methylmethionin) levels were affected by cultivars, portion and storage times in Kimchi made from Korean Chinese cabbages. From this study, the outward parts contained high levels of vitamin U in two cultivars of Winter Pride and 55 days. Vitamin U levels in Kimchi during storage were increased during fermentation at $4^{\circ}C$. Leaf parts were 1.1-5.2 times higher in vitamin U levels than midribs in both cultivars. The levels of vitamin U were shown highest in outward leaf parts of 55 days cultivars. Like vitamin U, free amino acid also showed much higher levels in leaves. Levels of amino acids showed similarly changing patterns at different parts and cultivars of Korean Chinese cabbages in Kimchi. Threonine, alanine and proline appeared relatively abundant amino acids in most parts of sample. Moreover, methionine as a precursor of vitamin U has been reported that leaf parts contained the higher levels than midrib parts. But methionine was shown most core leaf parts. Methionine as a precursor of vitamin U, may not play a role in an increase of vitamin U of Korean Chinese cabbages in Kimchi.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.20-25
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• 2021

[Purpose] The aim of this review was to discuss the effects of vitamin D on physical performance and musculoskeletal injuries in athletes and provide information on the field applications of vitamin D. [Methods] A systematic review was conducted to identify studies on vitamin D in athletes that assessed serum vitamin D levels, vitamin D and physical performance, vitamin D and musculoskeletal injuries, and practical guidelines for supplementation of vitamin D. [Results] Several studies reported that a high proportion of athletes had vitamin D insufficiency or deficiency. Low serum levels of vitamin D in athletes were more pronounced in winter than in other seasons, and indoor athletes had lower serum vitamin D levels than outdoor athletes. Low vitamin D levels have been demonstrated to have negative effects on muscle strength, power, and endurance; increase stress fractures and other musculoskeletal injuries; and affect acute muscle injuries and inflammation following high-intensity exercises. Therefore, periodic assessment and monitoring of vitamin D levels are necessary in athletes; the recommended serum level of 25(OH)D is > 32 ng/mL and the preferred level is > 40 ng/mL (-1). In those with low levels of vitamin D, exposure to sunlight and an improved diet or supplements may be helpful. Particularly, 2000-6000 IU of supplemental vitamin D3 can be consumed daily. [Conclusion] Vitamin D is a potential nutritional factor that can significantly affect physical performance and musculoskeletal injuries in athletes. The importance and role of vitamin D in athletes should be emphasized, and the current levels of vitamin D should be assessed. Therefore, it is essential to periodically evaluate and monitor serum vitamin D levels in athletes.

• Journal of Preventive Medicine and Public Health
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• v.45 no.6
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• pp.387-393
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• 2012

Objectives: Even though several epidemiological studies have observed positive associations between blood lead levels and homocysteine, no study has examined whether this association differs by the levels of micronutrients, such as folate, vitamin B6, and vitamin B12, which are involved in the metabolism of homocysteine. In this study, we examined the interactions between micronutrients and blood lead on homocysteine levels. Methods: This study was performed with 4089 adults aged ${\geq}20$ years old in the US general population using the National Health and Nutrition Examination Survey 2003-2004. Results: There were significant or marginally significant interactions between micronutrients and blood lead levels on mean homocysteine levels. Positive associations between blood lead and homocysteine were clearly observed among subjects with low levels of folate or low vitamin B6 (p-trend <0.01, respectively). However, in the case of vitamin B12, there was a stronger positive association between blood lead and homocysteine among subjects with high levels of vitamin B12, compared to those with low levels of vitamin B12. In fact, the levels of homocysteine were already high among subjects low in vitamin B12, irrespective of blood lead levels. When we used hyperhomocysteinemia (homocysteine>15 ${\mu}mol/L$) as the outcome, there were similar patterns of interaction, though p-values for each interaction failed to reach statistical significance. Conclusions: In the current study, the association between blood lead and homocysteine differed based on the levels of folate, vitamin B6, or vitamin B12 present in the blood. It may be important to keep sufficient levels of these micronutrients to prevent the possible harmful effects of lead exposure on homocysteine levels.

• 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 the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.713-722
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• 2009

Vitamin D levels have been reported to be associated with diabetes, obesity and metabolic syndrome. There have been studies on the nutritional status of vitamin D in postmenopausal women at Seoul and premenopausal women at Busan, and these studies showed that nearly no relationship between serum vitamin D levels and the obesity index existed. However, there have been no studies that examined about the relationship between serum vitamin D levels and insulin resistance in Korea. In this study, we investigated serum vitamin D levels and the relationship between serum vitamin D levels and insulin resistance (homeostasis model assessment of insulin resistance), obesity index (body mass index, percentage of body fat and waist circumference) in 180 premenopausal women (non-obese women 87.8%, obese women 12.2%) in spring (March~April), fall (September~October) and winter (January~February) at Daejeon. Serum vitamin D levels were lower in winter than in spring-fall, after adjusting for age and the obesity index. The frequency of vitamin D inadequacy (serum vitamin D levels were $\leq$ 20 ng/mL) was 45.5% in winter and, 23.5% in spring-fall, and which showed that vitamin D inadequacy was higher in winter than in spring-fall. Multiple regression analysis showed that serum vitamin D levels had no relationship with the obesity index or insulin resistance. There was no difference in the obesity index or insulin resistance between the vitamin D inadequacy and normal group, and there was no relationship between serum vitamin D levels and the obesity index or insulin resistance in non-obese and obese premenopausal women, respectively. In conclusion, serum vitamin D levels in premenopausal women at Daejeon were lower in winter than in spring-fall, and the frequency of vitamin D inadequacy was higher in winter than in spring-fall. Serum vitamin D levels had no relationship with the obesity index or insulin resistance in premenopausal women, most of whom were not obese.

• Journal of the Korean Home Economics Association
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• v.28 no.3
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• pp.25-32
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• 1990

This study was carried out to observe the effects of dietary sources of vitamin A and Zn levels on Zn and vitamin A distribution in rats fed excess vitamin A diet. In this study, 40 weanling male rats of the Sprague-Dawley strain, weighing 40-50g, were chosen and divided into for groups by dietary Zn levels and the sources of vitamin A. The two levels of dietary Zn were supplied: adequate Zn(30mg Zn/Kg diet), low Zn(3mg Zn/Kg diet). Excess vitamin A level was 100 times of RDA, retional and $\beta$-carotene were used as the sources of vitamin A. Vitamin A concentration of plasma and liver were significantly higher in rats fed retional than in rats fed $\beta$-carotene (p<0.05), but these were not affected by dietary Zn levels. Vitamin A accumulationin the liver appeared to be servere in rats fed retinol and low Zn diet. Zn levels of plasma and liver were not affected by the sources of vitamin A whereas Zn levels of kidney were slightly lower in retinol group, and Zn levels of tests were found to be significantly lower in rats fed retinol and low Zn diet. Fragility of erythrocytes in hypotonic saline soultion was greater in low Zn groups, whereas the lower fragility was found in adequate Zn groups in feeding excess vitamin A diet. Thus, these results suggest that an adequate Zn intake is preferable when excess vitamin A is taken, and $\beta$-carotene intake is more beneficial than retinol in order to diminish toxic effects of vitamin A.

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.118-126
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• 2010

A feeding trial was conducted to investigate the effects of different levels of dietary n-3 highly unsaturated fatty acids (HUFA) (1.1-5.6%) and vitamin E (70 and 400 mg/kg) on the growth and body composition of juvenile rockfish. Six isonitrogenous (45% crude protein) and isolipidic (17% crude lipid) diets were formulated to contain graded levels of n-3 HUFA and vitamin E. Diets 1, 2 and 3 consist of 400 mg vitamin E/kg diet with graded levels of 1.1, 3.0, and 5.6% n-3 HUFA, respectively. Graded levels of n-3 HUFA (1.1, 3.0, and 4.0%) were added in diets 4, 5 and 6, respectively, containing 70 mg vitamin E/kg diet each. At the end of feeding trial, growth performance of rockfish was affected by neither dietary n-3 HUFA nor vitamin E levels. Feed efficiency and hepatosomatic index were slightly decreased (P<0.05) with increment of dietary n-3 HUFA at each dietary vitamin E level. Dietary vitamin E and n-3 HUFA levels did not affect proximate composition and vitamin E concentration in the dorsal muscle of rockfish. Liver moisture and crude protein contents positively related to dietary n-3 HUFA levels. Liver lipid content and hematocrit value were significantly decreased (P<0.05) by increasing dietary n-3 HUFA levels. Eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3; DHA) concentrations in the dorsal muscle significantly correlated to dietary n-3 HUFA levels, except for fish fed the diet 6 containing 4% n-3 HUFA and 70 mg vitamin E/kg diet. EPA concentration in the dorsal muscle of fish fed the diet 6 was significantly lower than that of fish fed the diets 2, 3 and 5. The present findings suggest that feeding of diets containing excessive n-3 HUFA level with varying addition of vitamin E may alter fatty acid composition in the dorsal muscle, but do not affect growth of juvenile rockfish.

• Journal of Nutrition and Health
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• v.28 no.10
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• pp.967-975
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• 1995

To investigate effects of dietary fish oil and vitamin E level on the tissue levels of vitamin E and vitamin A and to see which tissue is sensitive to lipid peroxidizability, male Sprague-Dawley rats were fed experimental diets composed of either menhaden oil or soybean oil nad either low(equivalent to 17 mg $\alpha$-tocopherol) or high (equivalent to 140mg $\alpha$-tocopherol) vitamin E level for 4 weeks. Palsma TBARS per mg lipid was significantly elevated in rats fed fish oil with low vitamin E level compared to soybean oil-fed rats. TBARS levels of liver, heart, kidney and liver microsomes were also increased by feeding fish oil with low vitamin E level. Plasma TBARS level was significantly correlated with TBARS levels of liver, heart, kidney and liver microsome. Plasma vitamin E level of groups with vitamin E supplementation was elevated significantly as compared to the those without vitamin E supplementation, whereas vitamin E levels of liver, heart and kidney were not changed significantly. Plasma TBARS was negatively correlated with plasma vitamin E(r=0.5763, P<0.001) and A(r=-0.4523, P<0.01) and seems to be a good indicator of in vivo lipid peroxidative stress.