Vitamin deficiency syndrome

Water-soluble vitamins removed by hemodialysis (HD) contribute to malnutrition and vitamin deficiency syndromes. Patients receiving HD often require replacement of water-soluble vitamins to prevent adverse effects. The vitamins that may require replacement are ascorbic acid, thiamine, biotin, folic acid, riboflavin, and pyridoxine. Patients receiving HD should receive a multivitamin B complex with vitamin C supplement, but should not take supplements that include fat-soluble vitamins, such as vitamins A, E, or K, which can accumulate in patients with renal failure. 

As micronutrient deficiencies more or less ceased to be a large pubhc health problem in Western countries, the attention of scientists and manufacturers turned towards the many other functions that vitamins have in human metabolism. For the last several decades, pharmacological doses of most vitamins have been claimed to be of therapeutic value in a wide variety of conditions, which have only a superficial resemblance to the classic vitamin deficiency syndromes. The literature on which many of these claims are based unfortunately often consists of poorly conducted clinical trials or anecdotal reports. Properly designed studies are relatively few in number. No authoritative body has proposed quantitative recommendations or reference values for public health policy. 

The immunological disorders of Indian childhood cirrhosis and of tropical splenomegaly syndrome, where there are disturbances of the immunoglobulin synthesis as well as defects of cellular immune responses, may be the results of a combination of infections and perhaps certain types of unusual autoimmune phenomena—or even to vitamin deficiencies. 

Deficiency of vitamin E is characterized by low serum tocopherol levels and a positive hydrogen peroxide hemolysis test. This deficiency is believed to occur in patients with biliary, pancreatic, or intestinal disease that is characterized by excessive steatorrhea. Premature infants with a high intake of fatty acids exhibit a deficiency syndrome characterized by edema, anemia, and low tocopherol levels. This condition is reversed by giving vitamin E. 

Vitamin E is a generic term that represents four tocopherols and four tocotrienols of varying biological potency. The term tocopherol correctly refers to the methyl-substituted derivatives of to-col and is not synonymous with the term vitamin E. The tocopherols and tocotrienols may be referred to collectively as tocochromanols. Many of the diverse deficiency syndromes observed in animals experimentally deprived of vitamin E can be explained by the vitamin s acting as an antioxidant in stabilizing unsaturated lipids in biological membranes. 

Despite its considerable involvement in metabolic processes, no specific deficiency syndrome in humans has been attributed to vitamin B6 (19,103). A considerable number of nonvitamin functions have been suggested, but they remain controversial (102,103,108-111). These include roles in coronary heart disease, immune response, premenstrual syndrome, sickle-cell anaemia, asthma, autism, gestational diabetes, carpal tunnel syndrome, and cancer. 

Deficiency syndromes of Zn, Cu, Cr, Se and Mo have occurred in patients on total parenteral nutrition (TPN). There is still much research to be done in assessing the nutritional status of many elements and understanding their metabolism, so that normal dietary intake may be supplemented for health benefits. Table 2 is a summary of the amounts required, the functions and the nutritional (usually dietary) imbalances in humans, where known, of the essential trace elements.31-33 (Note that this summary does not attempt to include imbalances related to environmental toxicology and occupational hazards.) Several trace elements have important functions in the immune system. Some are associated with nucleic acid. Others have structural roles, such as Si in cartilage, F and Zn in bone. They may be parts of vitamins, such as Co in vitamin B12, or hormones, such as iodine in thyroid hormones, Zn and Cr have a role in the synthesis and action of insulin.31-33... 

Since almost all cases of vitamin B12 deficiency are caused by malabsorption of the vitamin, parenteral injections of vitamin B12 are required for therapy. For patients with potentially reversible diseases, the underlying disease should be treated after initial treatment with parenteral vitamin B12. Most patients, however, do not have curable deficiency syndromes and require lifelong treatment with vitamin Bi2 injections. 

There are some well-described deficiency syndromes, the well-established therapeutic use of vitamin K antagonists as oral anticoagulants and the well-known positive effects of pantothenic acid on skin hydration/moisturization and wound healing, which apparently lacks scientific solid base. Apart from that there are not many studies available on the treatment of dermatological disorders with these vitamins, either systemically or topically. Even less is known about transdermal penetration, stability, and formulation dependencies of possible topical applications. 

Celiac disease is the result of the development of inflammatory-allergic condition due to gluten intolerance. The disease occurs both in adults and in children in a number of countries all over the world. Its occurrence is fairly frequent, it is estimated that approximately 1% of the population suffers from it. Patients manifest not only gastrointestinal symptoms, but also symptoms which are the consequence of malabsorption syndrome, such as osteoporosis, hypochromic anemia, hypoproteinaemia, hypocalcemia, short stature in children, vitamin deficiency, secondary polysensibilization, and emotional disturbances. Moreover, it has been observed that the occurrence of autoimmunological diseases and neoplasms in patients who are not treated with gluten-free diet doubles (Swinson et al., 1983 Ventura et al., 1999). 

Vitamins are essential in mammalian physiology because their coenzyme forms are prosthetic groups or cofactors in many enzyme reactions or because they can perform certain specialized functions in the human organism. Vitamin A and its role in the visual process is an example. The biology of vitamins may be examined from the nutritional or biochemical points of view. The former is concerned with minimum daily requirements, dietary sources, bioavailability, and deficiency syndromes. The biochemist looks for structures, functional groups, conversion to coenzymes, mechanisms of action, mode of transport, and storage. Both aspects will be addressed in this chapter, though the emphasis will be on the biochemical properties of vitamins. 

It should be noted that deficiency states for some vitamins (e.g., pantothenic acid) are practically unknown in human beings. In such cases, deficiency states may be simulated by feeding the subject an appropriate vitamin antagonist. In another series of situations, vitamin deficiencies can be brought about by interfering with their absorption intentionally or may be the result of a disease process. Thus, fat-soluble vitamin deficiency may develop in cases of fat malabsorption syndromes (steatorrhea) sprue, pancreatic insufficiency, and bile duct obstruction. 

Normally there is very little fat in the feces. However, fat content in stools may increase because of various fat malabsorption syndromes. Such increased fat excretion is steatorrhea. Decreased fat absorption may be the result of failure to emulsify food contents because of a deficiency in bile salts, as in liver disease or bile duct obstruction (stone or tumor). Pancreatic insufficiency may result in an inadequate pancreatic lipase supply. Finally, absorption itself may be faulty because of damage to intestinal mucosal cells through allergy or infection. An example of allergy-based malabsorption is celiac disease, which is usually associated with gluten intolerance. Gluten is a wheat protein. An example of intestinal infection is tropical sprue, which is often curable with tetracycline. Various vitamin deficiencies may accompany fat malabsorption syndromes. 

Vitamins are small-molecular-weight organic substances that are necessary for essential biochemical reactions, growth, vitality and the normal functioning of the body. They must be supplied in the diet or in the form of dietary supplements. Central to the definition of a vitamin is that a lack of it will produce a specific deficiency syndrome, and supplying it will cure that deficiency. 

The principally pharmacological aspects of vitamins are described here.The nutritional aspects, physiological function, sources, daily requirements and deficiency syndromes (primary and secondary) are to be found in any textbook of medicine. 

Humans cannot synthesise vitamins in the body except some vitamin D in the skin and nicotinamide from tryptophan. Lack of a particular vitamin may lead to a specific deficiency syndrome. This may be primary (inadequate diet), or secondary, due to failure of absorption (intestinal abnormality or chronic diarrhoea), or to increased metabolic need (growth, pregnancy, lactation, hyperthyroidism). 

Rodriguez-Martin JL, Qizilbash N, and Lopez-Arrieta JM (2001) Thiamine for Alzheimer s disease. Cochrane Database of Systematic Reviews 2 CD001498. Thomson AD (2000) Mechanisms of vitamin deficiency in chronic alcohol misusers and the development of the Wernicke-Korsakoff syndrome. Alcohol Alcoholism 35(Suppl 1) 2-7. 

Vitamin A is used as a dietary supplement and for treatment of deficiency syndromes. It is not an endogenously produced vitamin thus, it must be provided through dietary or vitamin supplement sources. Vitamin A is essential for normal vision in dim light. Furthermore, it is needed for regulation of all growth and development, for maintaining mucous membrane integrity, and for the reproductive process. 

Vitamin D is a dietary supplement used for the prevention/treatment of deficiency syndromes. It is the only vitamin synthesized by the conversion of 7-dehydrocholesterol to cholecalciferol by exposure to sunlight or shortwave ultraviolet light. 

Vitamin E is used as a dietary supplement and for the treatment of deficiency syndromes. 

Thompson AD. Mechanisms of vitamin deficiency in chronic alcohol misuse and the development of the Wernicke-Korsakoff syndrome. Alcohol Alcohol 2000 35 Suppl 1 2-7. 

The minimum daily requirement (MDR) is the smallest amount of a substance needed by a person to prevent a deficiency syndrome. It is considered to represent the body s basic physiological requirement of the material. MDR values, which are established by the U.S. Food and Drug Administration (FDA), are not available for all vitamins. 

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