- 著者
- Maya KAMAO Yoshitomo SUHARA Naoko TSUGAWA Masako UWANO Noriko YAMAGUCHI Kazuhiro UENISHI Hiromi ISHIDA Satoshi SASAKI Toshio OKANO
- 出版者
- Center for Academic Publications Japan
- 雑誌
- Journal of Nutritional Science and Vitaminology (ISSN:03014800)
- 巻号頁・発行日
- vol.53, no.6, pp.464-470, 2007 (Released:2008-01-18)
- 参考文献数
- 32
- 被引用文献数
- 55 118
Several reports indicate an important role for vitamin K in bone health as well as blood coagulation. However, the current Adequate Intakes (AI) might not be sufficient for the maintenance of bone health. To obtain a closer estimate of dietary intake of phylloquinone (PK) and menaquinones (MKs), PK, MK-4 and MK-7 contents in food samples (58 food items) were determined by an improved high-performance liquid chromatography method. Next, we assessed dietary vitamin K intake in young women living in eastern Japan using vitamin K contents measured here and the Standard Tables of Food Composition in Japan. PK was widely distributed in green vegetables and algae, and high amounts were found in spinach and broccoli (raw, 498 and 307 μg/100 g wet weight, respectively). Although MK-4 was widely distributed in animal products, overall MK-4 content was lower than PK. MK-7 was observed characteristically in fermented soybean products such as natto (939 μg/100 g). The mean total vitamin K intake of all subjects (using data from this study and Japanese food composition tables) was about 230 μg/d and 94% of participants met the AI of vitamin K for women aged 18-29 y in Japan, 60 μg/d. The contributions of PK, MK-4 and MK-7 to total vitamin K intake were 67.7, 7.3 and 24.9%, respectively. PK from vegetables and algae and MK-7 from pulses (including fermented soybean foods) were the major contributors to the total vitamin K intake of young women living in eastern Japan.
- 著者
- Maya KAMAO Yoshihisa HIROTA Yoshitomo SUHARA Naoko TSUGAWA Kimie NAKAGAWA Toshio OKANO Hiroshi HASEGAWA
- 出版者
- The Japan Society for Analytical Chemistry
- 雑誌
- Analytical Sciences (ISSN:09106340)
- 巻号頁・発行日
- vol.33, no.7, pp.863-867, 2017-07-10 (Released:2017-07-10)
- 参考文献数
- 22
- 被引用文献数
- 6
This study aimed to develop a menadione (MD) determination method employing liquid chromatography–tandem mass spectrometry (LC-MS/MS) using a pseudo multiple reaction monitoring (MRM) technique, wherein two quadrupoles are used to monitor the same ion. Detection limits of 40 and 2 pg were obtained for MD and its deuterium-labeled form, respectively, whereas MD intra- and inter-assay coefficient of variation values were determined as 5.4 – 8.2%, with the corresponding recoveries equaling 90.5 – 109.6%. The developed method enables determination of MD in urine, plasma, cell extract, and culture media, demonstrating that pseudo multiple reaction monitoring can achieve quantification of compounds forming no suitable product ions, such as MD.
- 著者
- Naoko TSUGAWA Akiko KUWABARA Honami OGASAWARA Mayu NISHINO Kimie NAKAGAWA Maya KAMAO Hiroshi HASEGAWA Kiyoshi TANAKA
- 出版者
- Center for Academic Publications Japan
- 雑誌
- Journal of Nutritional Science and Vitaminology (ISSN:03014800)
- 巻号頁・発行日
- vol.68, no.3, pp.172-180, 2022-06-30 (Released:2022-06-30)
- 参考文献数
- 33
- 被引用文献数
- 4
Avoidance of sunlight and self-restraint due to the COVID-19 pandemic may contribute to reduced vitamin D status. This study provides comparable data on vitamin D status in Japanese young women and assesses the effect of lifestyle, including changes caused by the COVID-19 pandemic, on vitamin D status. In study 1, 39 young healthy Japanese women aged 21–25 y were recruited from May 2016–June 2017. Serum 25-hydroxyvitamin D (25OHD) concentration and diet and lifestyle information were obtained from participants each month (n=124). In study 2, using the same parameters as study 1, young women aged 21–23 y (n=10) were recruited in September 2020. In the results of study 1, we found the frequencies of vitamin D deficiency (25OHD<20 ng/mL) in spring, summer, fall, and winter were 90.5%, 62.5%, 81.5%, and 91.3%, respectively. The substantial difference of serum 25OHD concentration was obtained in spring (Δ3.6 ng/mL) and summer (Δ5.1 ng/mL) depending on the frequency of sunscreen use (0–2 d/wk, 3–7 d/wk). In study 2, serum 25OHD concentration in September 2020 was extremely lower than in September 2016 (13.2 ng/mL vs. 21.7 ng/mL). The number of days spent outside in 2020 decreased drastically compared with 2019. In conclusion, vitamin D deficiency was highly common in Japanese women in their early 20s, and frequent sunscreen use contributed to low vitamin D status. Moreover, because the decrease in days outside due to the COVID-19 pandemic obviously resulted in a decline in vitamin D status, both appropriate sunbathing and increased dietary vitamin D intake are recommended to young women.