Content of phylloquinone and menaquinone in the tissues of mummichog Fundulus heteroclitus fed diets containing different forms of vitamin K.

The contents of vitamin K in the plasma and tissues (kidney, liver and gonad) of mummichog Fundulus heteroclitus fed diets supplemented with different vitamin K groups were determined. The vitamin K mainly detected in the gastrointestinal tract of each experimental group was the one supplemented in the respective diet, and all other forms of vitamin K were observed at low concentrations. This implies that the main vitamin K source for mummichog is their food. Further evidence that the main vitamin K source is the food is that the elevation of vitamin K concentrations in the plasma and other tissues in this experiment was brought about by vitamin K added to the feed. The phylloquinone-rich diet raised the phylloquinone concentration in the plasma and the tissues much higher than the diets supplemented with short and/or long chain menaquinones. This indicates that phylloquinone is more easily accumulated into the body of fish than the menaquinone homologues. There were apparent differences in absorption and deposition of vitamin K between females and males. This may be a factor in the high mortality in male mummichog during the spawning season but further clarification of the causes of the mortality is required.