Quality of vitamin K analysis and food composition data in Finland

The phylloquinone content of plant-based foods, e.g. oils and margarines, vegetables, fruits, berries, and cereal products consumed in Finland were recently published. Based on this data the quality of vitamin K analysis and food composition data are discussed, emphasising method validation and the effects of the sampling system. The details of the procedures are carefully documented in the original papers to facilitate evaluation of the data by the users. The results showed great variation in the phylloquinone content of individual subsamples of different items, as well as in pooled samples of vegetables and margarines. The number of subsamples should thus always be considerable. Furthermore, repeating the sampling of items regarded as important is recommended.