Home Recreation: A Way of Life Modern society tends to fragmentize life Sports Films History Baseball: The Components of Profit Estrogen and Antagonists Diet and Nutrition The Vitamins Vitamin B Vitamin C Vitamin D Vitamin E Let the stars size up your shopping style Astrology: Magic or Science? Jamaica For Cyclists Maine: Earliest Inhabitants The passion for football Changes in Body Weight The Metabolism and Energy Transformations of Healthy Man Normal Activity Restricted by the Conditions of Experiments Metabolism During Specific Activities and Movements Public Colleges M to N N to Z What Is It We Want? Directed Thinking On Being Oneself Economics Is a Branch of Biology Life Is Also Frustration How Goods are Bought and Sold Leisure and work The Pecuniary Standard of Living The Uses of Time Teaching People to Want Things Art as leisure The Loss of Privacy The Great Emptiness	The Vitamins - Vitamin C Vitamin C is the anti-scorbutic principle. This is the most unstable of the vitamins and is especially susceptible to destruction by contact with the oxygen of the air. Birds apparently do not require this vitamin, and this has also been demonstrated for the rat. In these species the body has the capacity to synthesize the vitamin from some other component of the diet, since the livers of rats grown to maturity on diets free from C are very potent in curing acute scurvy in guinea pigs. Deficiency of vitamin C produces characteristic pathological changes. It appears that the endothelial cells lose their power to produce the cement substance which holds them together; and so the capillary blood vessels, whose walls consist of a single layer of endothelial cells, break down, allowing the blood to ooze out into the tissues. Hemorrhage is therefore the most outstanding change resulting from vitamin C deficiency; but another effect, namely, rarifaction of the bones, is of great importance. While scurvy is developing, the bones become rarified and fragile. Rarifaction of the alveolar bone which forms the sockets of the teeth is the cause of looseness of the teeth seen in scurvy. Approximately forty days of total deprivation of vitamin C causes the appearance of the clinical signs of scurvy. Höjer made the interesting observation that in approximately half the time required to produce clinical scurvy the odontoblastic layer in the teeth is affected. If approximately seven-tenths or eight-tenths of the minimum protective dose of vitamin C is given to guinea pigs for ten to fourteen days, the odontoblastic membrane will show abnormal structure, the cells being of unequal size. If but half the minimum protective dose is given, the odontoblastic layer will have separated from the dentine, the fibrils apparently having become detached. If but threetenths, or thereabouts, of the protective dose is given, the odontoblastic layer will have broken up into islets of distorted cells. This may be of great significance to the health of human teeth, since doubtless many people, at different times, have gone for more than twenty days entirely without a supply of vitamin C. If changes comparable to those in the guinea pig take place in the human teeth, it is not unreasonable to suppose that subsequent death of the pulp would be the result of this type of specific starvation. The frequent occurrence of lifeless pulps in otherwise normal-appearing teeth demands an explanation as to its etiology. The recent researches on animals showing odontoblastic damage seem to account for the condition seen in many human teeth. Vitamin C is most abundant in fresh vegetable foods, but the livers of well-fed animals contain a store of it. Pasteurization of milk destroys practically all of it; and as pasteurization of milk has increased in cities, infantile scurvy has likewise increased. This is not a sound argument against pasteurization, since it is now a general practice to give infants some suitable fruit or vegetable juice which will supply what has been destroyed in the heat treatment of the milk. Citrous fruits and tomatoes are outstanding as rich sources of this vitamin. Ordinary canned tomatoes are little inferior to the fresh article, but bottled sterilized orange and lemon juice have generally been found to be without value in this respect. Raw potatoes, raw cabbage, lettuce, turnips, etc., are excellent sources of the anti-scorbutic vitamin. The readiness with which vitamin C is destroyed on heating milk and the absence of the vitamin from foods cooked in the ordinary way led, a few years ago, to the unwarranted assumption that canned fruits and vegetables would be worthless as anti-scorbutic foods. That this was an error was pointed out by Kohman and Eddy, who showed that modern canning processes tend to preserve much of the vitamin C content of the foods. The destruction in ordinary cooking results from heating the food while it still contains, dissolved in its juices, about 5 per cent by volume of oxygen, and from continued heating in contact with air. If this oxygen is removed by immersing the food for a few hours in water before processing, the subsequent heat treatment does not destroy the vitamin. Modern canning methods involve subjecting the foods to diminished pressure and to removal of the air by steam. This system of cooking is responsible for the preservation of the antiscorbutic quality of most canned foods.