Diseases vitamin deficiency

Medical personnel who work in affluent areas are unlikely to see large numbers of people with vitamin deficiency diseases. However, certain groups of the population are particularly at risk, such as low-income families and chronically ill patients. The classic symptoms of any vitamin deficiency disease as observed in laboratory animals are often blurred in humans. The clinical picture is often complicated by deficiencies of other vitamins, minerals, calories, and protein and by infections and parasite infestations, which usually accompany longstanding malnutrition. Biochemical, physiological, and behavioral changes can occur in the marginal deficiency state without or before the appearance of more specific symptoms. Since the nonspecificity of these changes makes them difficult to detail, this section focuses on the symptoms associated with individual vitamin deficiency diseases. 

Both statements are valid but the second statement, (b), states more accurately why it is that we need vitamins. Vitamin-deficiency diseases, Such as scurvy, result when certain catabolic and anabolic reactions are not able to proceed efficiently in the absence of these important nutrients. 

Know the etiology of various vitamin deficiency diseases. 

A vitamin-deficiency disease first described in 1630 by Jacob Bonitus, a Dutch physician working in Java ... 

Scurvy is one of the oldest vitamin deficiency diseases recorded and the first one to be cured by adding a vitamin to the diet. Scurvy was a common malady of sailors of the age of exploration of the New World. It has been recorded that Vasco da Gama was supposed to have lost half of his crew to scurvy in his journey around the Cape of Good Hope at the end of the fifteenth century and Richard Hawkins reported that he lost 10,000 sailors from the disease a century later. 

The absence of one or more vitamins from the diet or poor absorption of vitamins can cause vitamin deficiency diseases. 

Two standards have been established to plan diets that contain adequate supplies of the vitamins and to aid in diagnosing vitamin deficiency diseases. 

The fat-soluble vitamins share many properties despite their limited chemical similarity. They are absorbed into the intestinal lymphatics, along with other dietary lipids, after emulsification by bile salts. Lipid malabsorption accompanied by steatorrhea usually results in poor uptake of all the fat-soluble vitamins. Deficiency disease (except in the case of vitamin K) is difficult to produce in adults because large amounts of most fat-soluble vitamins are stored in the liver and in adipose tissue. The fat-soluble vitamins are assembled from isoprenoid units this fact is apparent from examination of the structures of vitamins A, E, and K cholesterol, the precursor of vitamin D, is derived from six isoprenoid units (Chapter 18). Specific biochemical functions for vitamins A, D, and K are known, but a role for vitamin E, other than as a relatively nonspecific antioxidant, remains elusive. 

Before its true nature as a vitamin deficiency disease was firmly established, a connection was made between the incidence of pehagra and the consumption of mouldy maize. Several Penicillium species were isolated from this source. Examination of one of these, P. charlesii, by Raistrick between 1933 and 1935 led to the isolation of a series of acidic metabohtes that were derivatives of tetronic acids and exemplified by L-y-methyltetronic acid (6.11), carolic acid... 

NAD+, derived from niacin and coenz)rme A, derived from pantothenic acid. Obviously, a deficiency in any of these vitamins would seriously reduce the amount of acetyl CoA that our cells could produce. This, in turn, would limit the amount of ATP that the body could make and would contribute to vitamin-deficiency diseases. Fortunately, a well-balanced diet provides an adequate supply of these and other vitamins. 

Problem 23.33. Can any vitamin deficiency diseases occur in adults or children who ingest the correct... 

In the early part of this century many vitamin deficiency diseases were identified and cured. Vitamin D cured rickets. Vitamin C (ascorbic... 

Many molecular diseases that have arisen in the course of evolution have been controlled in a somewhat similar manner. Human beings require many vitamins. Pellagra is an example of a vitamin deficiency disease—a molecular disease that originated through a mutation, perhaps millions of years ago, and was then cured by the heterotrophic process of eating other organisms that manufacture the vitamin. Scurvy and other avitaminoses are also diseases of this sort. It is not customary for us to admit that we have these diseases, because we treat them as a matter of habit by eating what is called a proper diet. 

Trace nutrients, micronutrients a general term for any essential dietary component required in small quantities, like TVace elements (see) and Vitamins (see). Deficiency of T.n. leads to deficiency symptoms, e.g. vitamin deficiency diseases. T.n. act catalytically or are precursors of catalytically active substances in the organism. Essential amino acids therefore have an equivocal status in this classification. Flavoring principles are definitely not T. n. 

Vitamins have unique chemical structures, that affect their solubilities in different parts of the human body. Vitamins B and C are water soluble, for example, whereas vitamins A, D, E, and K are soluble in nonpolar solvents and in the fatty tissue of the body (which is nonpolar). Because of their water solubility, vitamins B and C are not stored to any appreciable extent in the body, and so foods containing these vitamins should be included in the daily diet. In contrast, the fat-soluble vitamins are stored in sufficient quantities to keep vitamin-deficiency diseases from appearing even after a person has subsisted for a long period on a vitamin-deficient diet. 

Aside from specific vitamin-deficiency diseases and a few other specific diseases the field of nutrition generally has only recently been allowed to make real contributions in the treatment of disease. There is... 

Since the start of the enrichment program in 1941, the available supplies of the B vitamins— thiamin, riboflavin, and niacin—and of iron in the national diet have increased. The enrichment program has played a significant role in the practical elimination of the vitamin deficiency diseases ariboflavi-nosis, beriberi, and pellagra, and of simple iron deficiency anemia. 

Some coenzymes serve as carriers of chemical groups, hydrogen atoms, or electrons. Others such as ATP function in energy coupling reactions within the cell and are often regarded as a substrate rather than a coenzyme. Other coenzymes have more complex structures and are derivatives of vitamins. They act at the active site of the enzyme by combining with the substrate in a way that permits the reaction to proceed more readily. By definition, vitamins cannot by synthesized by the host, and must therefore be provided by the diet. Their presence are thus required for normal growth and health and their absence causes specific or vitamin deficiency diseases. 

Filling the Requirement of Vitamins. Deficiency diseases appear very rarely under adequate nutritional situations. Such diseases are the consequence of unbalanced nutrition. Hypovitaminoses are actually clinically more significant than the avitami-... 

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