Food vitamins and minerals can lead to diseases that can have far-reaching effects on health. For instance, 30% of the world's population either has, or is at risk for developing, iodine deficiency. It is estimated that at least 3 million children are blind due to vitamin A deficiency. Vitamin C deficiency results in scurvy. Calcium, Vitamin D, and phosphorus are inter-related; the consumption of each may affect the absorption of the others. Kwashiorkor and marasmus are childhood disorders caused by lack of dietary protein. Many individuals limit what foods they eat for reasons of morality, or other habit. For instance, vegetarians
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