This chapter describes the absorption, distribution, storage, and metabolites of vitamins K and related quinones. About 10% of vitamin K, dl-α-tocopherylquinone, and dl-α-tocopherol, administered in emulsified form, are absorbed. Vitamin K and dl-α-tocopherylquinone differ from dl-α-tocopherol as these two substances are absorbed and excreted faster. Ubiquinone-9 is absorbed much more slowly than dl-α-tocopherol and to the extent of only about 4% of the administered dose. It is, however, even better retained than dl-α-tocopherol. Maximum tissue levels are obtained only after about 24 hours. The excretion in the urine within that period amounts to only about 10% of the absorbed quantity. The distribution pattern of vitamin K, dl- α -tocopherylquinone, and dl-α-tocopherol in the body of rats is similar. Only dl-α-tocopherol is stored highly selectively in the adrenals. The liver is the preferred storage place for ubiquinone-9. The small amounts of radioactivity originally present in other organs move to the liver so that after 24 hours 97% of the total amount can be found there. All quinones —namely vitamin K, vitamin MK-4, dl-α-tocopherylquinone, phytylplastoquinorie, and ubiquinone-9, are metabolized in the same way, yielding y-lactones that are excreted in the urine as conjugates having side chains of seven carbon atoms, which correspond to the metabolite of vitamin E identified previously.