The phylloquinone content of plant-based foods, e.g. oils and margarines, v
egetables, fruits, berries, and cereal products consumed in Finland were re
cently 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 o
f vegetables and margarines. The number of subsamples should thus always be
considerable. Furthermore, repeating the sampling of items regarded as imp
ortant is recommended. (C) 1999 Elsevier Science Ltd. All rights reserved.