Vitamin K substances

Antagonists of vitamin K substances include dicoumarol, sulfonamides, antibiotics, a-tocopherol quinone, dihydroxysteanc acid glycide, salicylates, iodinin, warfarin. Synergists include ascorbic acid, somatotropinn (growth hormone), and vitamins A and E. 

Assuming therefore that only vitamin K substances with a typical side chain, as in vitamin Ki and the forms of vitamin Kj, are active in metabolism, the above-mentioned differences in the biological activity of vitamin Ki and of menadione can be explained. Menadiones, necessary only in very small doses to cure nutritional vitamin K deficiency, may be quantitatively transformed into the active vitamin Ka form. This bio thesis, being limited, however, as described in Section VI, is insufficient to provide the high amount of metabolically active vitamin Kj needed to counteract Dicumarol poisoning. 

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