Scurvy on a diet devoid or nearly devoid of vitamin C, had blood levels of vitamin C too low to be accurately measured when they developed signs of scurvy, and in the Iowa study, at this time were estimated (by labeled vitamin C dilution) to have a body pool of less than 300 mg, with daily turnover of only 2.5 mg/day. The vast majority of animals and plants are able to synthesize vitamin C, through a sequence of enzyme-driven steps, which convert monosaccharides to vitamin C. However, some mammals have lost the ability to synthesize vitamin C, notably simians and tarsiers.
Names of the days of the week nundinal cycle with the seven-day week. Our earliest evidence for this new system is a Pompeiian graffito referring to the 6th February ("viii idus Februarius") of the year AD 60 as "dies solis" ("Sunday"). Another early witness is a reference to a lost treatise by Plutarch, written in about AD 100, which addressed the question of "Why are the days named after the planets reckoned in a different order from the actual order?". The days were named after the planets of Hellenistic astrology, in the order Sun, Moon, Mars ("Ares"), Mercury ("Hermes"), Jupiter ("Zeus"), Venus ("Aphrodite") and Saturn ("Cronos"). The