Vitamin K: content in food consumed in São Paulo, Brazil

Abstract

Recent research on Vitamin K has shown its importance in maintaining vascular and bone health. Brazilian food composition tables do not show phylloquinone content in national foods. These data are needed to obtain more reliable results in nutritional status assessment studies of individuals in relation to this vitamin as studies have shown a geographical influence in food phylloquinone content. This study aims to determine phylloquinone (Vitamin K 1 ) levels in its most important source: dark green leaved vegetables. Several varieties of vegetables were purchased directly from CEAGESP (General Warehouse Company of São Paulo) at different times. Phylloquinone was extracted using organic solvents and quantified by High Performance Liquid Chromatography -HPLC. Results show the concentrations of phylloquinone in commonly consumed foodstuffs. In general, results showed variations with data from literature on the amount of Vitamin K in the plants analysed.

Warfarin drug interaction with vitamin K and other foodstuffs

“…In Brazil, there are still no tables with phylloquinone levels in food, so it is necessary to use data from international literature, such as the United States Department of Agriculture (USDA). However, a recent study quantified vitamin K content in vegetables consumed in the city of São Paulo, Brazil 18 ; studies such as these are relevant since they may contribute to the evaluation of vitamin K in foods of national origin. In this sense, some differences can be observed in the vitamin K content of some vegetables between the two data sources.…”

“…In other words, warfarin inhibits the VKOR enzyme of vitamin K, which prevents its cyclic interconversion, preventing the carboxylation of the GLA residues from the coagulation factors (II, VII, IX, and X), as well as the proteins C, S, and Z (Figure 1) 21,27 18 . Thus, the time between initiation of warfarin administration and onset of action may be explained by the factor clearance rate, so intravascular clots may continue to appear during the first three days of therapy.…”

Development ofafoodfrequency questionnaire to determine vitamin k intake in anticoagulated patients: a pilot study

“…First, a list of food items that could potentially be included in the FFQ was made, based on 24-hour dietary recalls available in previous studies conducted with a similar study population, and on a FFQ for vitamin K previously developed and validated in the USA 10,13 . Second, a literature review of articles including food composition tables for vitamin K was conducted, to identify and select foods with ≥ 5μg of vitamin K/100g of food, to be included in the final version of the questionnaire 1,14,15,16,17,18,19,20 . Of these, one study was carried out with food in Brazil 19 .…”

“…Second, a literature review of articles including food composition tables for vitamin K was conducted, to identify and select foods with ≥ 5μg of vitamin K/100g of food, to be included in the final version of the questionnaire 1,14,15,16,17,18,19,20 . Of these, one study was carried out with food in Brazil 19 . The content of vitamin K in each portion of foods included in the questionnaire was calculated by the mean of the vitamin concentrations described in these tables.…”

“…Another limitation is related to the scarcity of data on the content of vitamin K in foods produced in Brazil. Of the 36 items included in the FFQ, only 12 have been analyzed previously in a Brazilian study that determined the vitamin K content in foods consumed in the country 19 .…”