• Journal of Nutrition and Health
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• v.30 no.3
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• pp.299-306
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• 1997

Vitamin K takes part in both blood coagulation and bone metabolism via the carboxylation of glutamate residues. This study was performed to examine the relationship between dietary phylloquinone intake and bone mineral denisty(BMD) among postmenopausal Korean women (n=70, age=56). The bone mineral density of the lumbar spine and femoral neck were measured by dual X-ray absorptiometry(DEXA). Daily intakes of phylloquinone and calcium were assessed using a food frequency questionnarie. As a results, body weigh, height and body mass index were not correlated with BMD. However, the number of years since monopause and daily intakes of calcium were significantly correlated with BMD. Although daily intakes of phylloquinone were not correlated with BMD, women with relatively high BMD consumed more phylloquinone than those with lower BMD. The average daily phylloquinone and calcium intakes of the 70 postmenopausal women were 725.8ug/day, ten times more than the American RDA and 406.7mg/day, 1/2 of the American RDA for those nutrients, respectively. The major food sources for phylloquinone were seaweed, spinach and kale, whereas the food sources of calcium were milk, sardines, and yogrut. Further studies are needed to clarify the effects of dietary phyloquinone on its serum levels and BMD.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.186-191
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• 2015

BACKGROUND/OBJECTIVES: Rheumatoid arthritis (RA) is associated with an excess mortality from cardiovascular disease which is likely attributed to an atherogenic lipid profile. Among nutritional factors vitamin K has been recently focused as a pivotal nutrient in improvement of lipid related markers. Thus, this study was designed to determine the effects of vitamin K on lipid profile in this disease. SUBJECTS/METHODS: Fifty eight patients with definitive RA were participated in the present double blind placebo controlled study. They were randomly allocated into two groups to receive vitamin $K_1$ as phylloquinone [10 mg/day] (n = 30) or placebo pills (n = 28), for eight weeks. In order to control the effects of probable confounders dietary intakes, anthropometric measurements including weight and height, clinical status using disease activity score-28 (DAS-28), physical activity and anxiety status were evaluated at baseline. Moreover, serum levels of lipid related markers including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) were measured at baseline and at the end of intervention. RESULTS: There were no significant differences between the two groups regarding any of the baseline characteristics. After adjusting for some relevant confounders, in comparison between two groups, we observed no significant changes in lipid related markers at the end of intervention. Also, there was no significant difference between before and after intervention values within groups (P > 0.05). CONCLUSIONS: Function of vitamin $K_1$ in lipid profile modification remains still controversial. This study showed that vitamin $K_1$ has no effect on lipid profile in women with rheumatoid arthritis. Further studies with a longer follow-up are required to determine the effects of vitamin K on atherogenic lipid profile.

• Journal of Nutrition and Health
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• v.39 no.6
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• pp.529-538
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• 2006

The prevalence of chronic diseases have been rising in the developing countries because of their increased animal foods consumption and Western lifestyle. Lately, vegetarian diet that exclude animal products get public attention. The purpose of this study was to evaluate the nutritional status and dietary quality of vegetarians, and their consumption of vitamin K and was also assessed. Vegetarians including strict vegan and lacto-ovo-vegetarian consumed their diet at least over 6 months. Carnivores were gender and age matched with vegetarians and they consumed over 50% of protein and fat from animal sources. Current nutrient intakes and dietary quality were assessed using 3-day food records and intake of vitamin K was calculated from the data base of 'Provisional Table on the vitamin K contents of foods, USA'. Blood sample were collected and biochemical parameters and plasma phylloquinone concentrations were analyzed. Anthropometric data from vegetarian and carnivore were not significantly different. The intake of calories, protein, vitamin $B_2$, Ca and Zn of the vegetarians were remarkably lower than RDA for each nutrient. Moreover, index of nutritional quality and nutrient adequacy ratio of vegetarians were lower than those of carnivore. Vegetarian consumed less fat and the ratio of n-6/n-3 fatty acid was lower in vegetarian. The intake of essential amino acids in vegetarian was significantly lower than that of carnivore. The vitamin K consumption and plasma phylloquinone concentration of vegetarian were significantly higher than those of carnivore (p<0.05). The dietary vitamin K consumption was positively correlated with plasma phylloquinone levels in vegetarian (p<0.01).

• Food Science and Preservation
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• v.30 no.6
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• pp.929-943
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• 2023

This study analyzed the variation in vitamin K content in conger eel (Conger myriaster) caught off Tongyeong, Gyeongsangnam-do, Korea, focusing on the influence of size (large and small) and harvest period (monthly throughout 2021). We applied enzymatic extraction and HPLC-fluorescence methods for the analysis of vitamin K₁ (phylloquinone) and K₂ (menaquinone). The vitamin K content in conger eel varied significantly with size and harvest season (p<0.05). In large-sized samples, the phylloquinone content peaked in July (0.80±0.09 ㎍/100 g), while the highest menaquinone content was in May (0.79±0.11 ㎍/100 g). Conversely, in small-sized conger eels, the highest phylloquinone was found in December (1.94±0.15 ㎍/100 g), and the peak menaquinone level was in January (0.66±0.02 ㎍/100 g). The fat content was highest in July for large samples and in January for smaller ones. There was a positive correlation between fat and total vitamin K contents in conger eel (r=0.631, 0.667). Method validation and quality control measures ensured data reliability for vitamin K₁ and K₂ analyses. This study provides reliable information on the size and seasonal variations of vitamin K in conger eels, a staple in the Korean diet. This information is valuable for inclusion in Korea's national food nutrition database and for formulating future national health and nutrition policies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1791-1795
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• 2014

The objective of this study was to compare two extraction methods for determination of vitamin K1 (phylloquinone) in vegetables. In addition, analytical method validation parameters such as accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and linearity were calculated to ensure the method's validity. Vitamin K1 was quantified by reversed-phase HPLC using post-column derivatization and fluorescence detection ($Ex{\lambda}=243nm$, $Ex{\lambda}=430nm$). Higher analytical values were observed using solvent extraction compared to those from the enzyme extraction method. The results from the method validation showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9994. The LOD and LOQ were 0.1335 and 0.2784 ng/injection volume ($50{\mu}L$), respectively. The inter-day precision and inter-day precision were 2.0% and 2.1%, respectively. Overall recovery was close to 100% (n=5). The phylloquinone contents ranged from 9.42 to $1,212.57{\mu}g/100g$. Our study provides reliable data on the phylloquinone contents in commonly consumed vegetables in Korea.

• Journal of Photoscience
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• v.9 no.2
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• pp.367-369
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• 2002

Chlorophyll (ChI) a' is the Cl3$^2$-epimer of ChI a which is the constituent of P700, the primary electron donor of Photosystem (PS) I, of a thrmophilic cyanobacterium, Synechococcus elongatus, whose structure was recently determined by X-ray crystallography. To determine whether PS I of diverse oxygenic photosynthetic organisms universally contain one molecule of ChI a ’, pigment compositions of thylakoid membranes and PS I complexes isolated from cyanobacteria, green algae, red algae and higher plants were determined by reversed-phase HPLC. The results show that involvement of one ChI a'molecule in PS I is the universal feature for Chi a-based PS I of oxygenic photosynthetic organisms.

• Journal of Dairy Science and Biotechnology
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• v.29 no.1
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• pp.33-39
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• 2011

Vitamin K, which is a nutritional factor, play a role in the regulation of bone metabolism. Vitamin K exists naturally in 2 forms, namely, vitamin $K_1$ (phylloquinone) in green plants and vitamin $K_2$ (menaquinone) in animals and bacteria. Vitamin $K_1$ has an effect on bone metabolism. Vitamin $K_2$ is essential for the ${\gamma}$-carboxylation of osteocalcin, a bone matrix protein containing ${\gamma}$-carboxyglutamic acid (Gla) which is synthesized in osteoblast of bone tissues. This paper is to provide the basic information of vitamin K by supplying function and biological activity of vitamin K together with vitamin K producing lactic acid bacteria and it's utilization for the dairy products production.

• Journal of Nutrition and Health
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• v.32 no.6
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• pp.726-731
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• 1999

Many studies show that the bone loss in postmenopausal women is closely related with status of vitamin K. The purpose of this study is to observe the effects of the vitamin K supplements on the carboxylation of serum osteocalcin in postmenopausal women. Twenty-four healthy postmenopausal women were recruited for the double-blind controlled study. Before and after daily administration of 1.0mg of phylloquinone for one month, the levels of serum vitamin K, osteocalcin, undercarboxylated osteocalcin were measured. Daily intake of vitamin K was also calculated. After the 4-weeks of supplements of 1.0mg/day of vitamin K, there were no significant differences for the levels of serum vitamin K, osteocalcin, and ucOC between the experimental and placebo groups. In this study, it was not found that the supplements of vitamin K to the postmenopausal women had any positive effects on.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1194-1199
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• 2015

Vitamin $K_1$ (phylloquinone) content of commonly consumed foods in Korea were determined by solvent extraction followed by reversed-phase liquid chromatography using post-column derivatization and fluorescence detection. Samples were obtained in the years of 2013 and 2015. In this study, 46 vegetables, 14 fruits, and 6 legumes were analyzed. Relatively higher amounts of vitamin $K_1$ were found in sweet potato leaves, green kiwi, and mung beans among vegetables, fruits, and legumes, respectively. The content of vitamin $K_1$ in vegetables including spinach, broccoli, and potato ranged from non-detectable (ND) to $1,467.3{\mu}g/100g$. The content of vitamin $K_1$ in fruits ranged from ND to $42.7{\mu}g/100g$. The content of vitamin $K_1$ in legumes, including soybeans, mung beans and peas ranged from 1.7 to $63.4{\mu}g/100g$. In addition, the analytical method validation parameters including recovery, reproducibility, repeatability, peak purity, and linearity were calculated to ensure the method's validity. The results showed high linearity with a correlation coefficient of 0.9999. Overall recovery was close to 100% (n=5). This study revealed reliable vitamin K content in commonly consumed foods in Korea for a nutritional information and food composition database.

• Journal of Nutrition and Health
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• v.32 no.3
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• pp.287-295
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• 1999

This study was conducted to observe the effect of vitamin K on bone metabolism in postmenopausal women. Twenty-four healthy postmenopausal women recruited for this one-month, double-blind controlled study. Before and after daily administration of 1.0mg of phylloquinone the levels of serum vitamin K, osteocalcin, under-carboxylated osteocalcin, and urinary deoxy-phyidinoline were measured. The serum vitamin K concentration of Koran women as well as the average dietary intake of vitamin K was shown to be higher than the average levels of foreign women. However, no correlation between serum vitamin K concentration and vitamin K intake was found. Also, serum vitamin K concentration showed no special correlation with either bone mineral density or bone turnover markers in the study group. However, women with low serum vitamin K concentration(vitamin K-low group)had lower bone mineral density levels. After supplementation with 1.0mg/day of vitamin K, there were no changes in the levels of serum vitamin K, osteocalcin, ucOC, or u-DPD. Vitamin K supplementation did not seem to have any positive effects on bone metabolism through carboxylation. It can, however, be expected that vitamin K supplementation has a positive effect on bone metabolism in postmenopausal women with especially low serum vitamin K concentrations.