Constructing a provisional Taiwan food phylloquinone content database and its application

95

Dietary phylloquinone levels sufficient for blood coagulation may be suboptimal for maintaining bone health. Inadequate dietary intakes of phylloquinone may lower the degree of osteocalcin carboxylation thus contributing to an elevated risk of osteoporosis. The present study assessed dietary phylloquinone intake and its correlation with serum osteocalcin carboxylation of Taiwanese elderly by a self-constructed food phylloquinone content database. The database was constructed by compiling the related databases from 4 countries with the addition of phylloquinone contents of frequently consumed local vegetables analyzed by high performance liquid chromatography (HPLC) in our laboratory. The results indicated that local green leaf vegetables such as amaranth, Bok Coy, spinach and sweet potato leaf contained > 300 μg phylloquinone/100 g, and soybean oil contained 42 μg phylloquinone/100 g. We further assessed the dietary phylloquinone intakes of elderly in the Yi-Yuan accommodation institution in Taipei County, using this provisional food phylloquinone content database. The mean daily intakes of phylloquinone from their 3-day food records in summer and winter were 352 ± 170 μg/day and 389 ± 167 μg/day, respectively. Among 37 elderly, mean percentage of undercarboxylated osteocalcin (%ucOC) in summer and winter were 27% and 24%. There was a significant negative correlation between phylloquinone intake and %ucOC in winter (r = -0.52). Moreover, we used the phylloquinone database and 24-HR recalls in series of nationwide nutritional surveys to estimate the daily phylloquinone intakes of Taiwanese. The mean daily phylloquinone intake of 19-64 year-old males and females were 558 ± 742 μg/day and 549 ± 703 μg/day, and those of elderly men and women (>64yr) were 430 ± 474 μg/day and 436 ± 513 μg/day. In summary, green leafy vegetables are the predominant dietary sources of phylloquinone, followed by certain vegetable oils for Taiwanese. The mean daily phylloquinone intakes of Taiwanese are higher than US Dietary Reference Intakes (DRIs) of 120 and 90 μg/day for men and women, respectively.