Vitamin the vitamin. People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency. In contrast, restrictive diets have the potential to cause prolonged vitamin deficits, which may result in often painful and potentially deadly diseases. Well-known human vitamin deficiencies involve thiamine (beriberi), niacin (pellagra), vitamin C (scurvy), and vitamin D (rickets). In much of the developed world, such deficiencies are rare; this is due to (1) an adequate supply of food and (2) the addition of vitamins and minerals to common foods (fortification). In addition to these classical vitamin deficiency diseases, some evidence has also suggested
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