Niacin deficiency

Bioassays procedures have been developed in species such as chicks which have been fed a niacin-deficient diet. Due to the fact that, for example, tryptophan is a biological precursor of niacin, niacin can be produced from other sources (55). As a result, the tryptophan content of the diet has to be monitored carefully for accurate results. 

The RDA for niacin is based on the concept that niacin coen2ymes participate in respiratory en2yme function and 6.6 niacin equivalents (NE) are needed per intake of 239 kj (1000 kcal). One NE is equivalent to 1 mg of niacin. Signs of niacin deficiency have been observed when less than 4.9 NE/239 kj or less than 8.8 NE per day were consumed. Dietary tryptophan is a rich source of niacin and the average diet in the United States contains 500—1000 mg of tryptophan. In addition, the average diet contains approximately 8—17 mg of niacin. In total, these two quantities total 16—34 NE daily. Table 5 Hsts the RDA and U.S. RDA for niacin (69). 

NADP can be converted to nicotinic acid adenine dinucleotide phosphate (NAADP), which has distinct functions in the regulation of intracellular calcium stores. The studies of these new roles of NAD(P) in metabolism are in their early stages, but they might soon help to better understand and explain the symptoms of niacin deficiency ( pellagra) [1]. 

That individual monkeys have distinctive niacin needs was shown by recent work of Tappan and co-workers.59 One animal, for example, required only 11 weeks to show niacin deficiency weight loss by this animal was halted only when 30 mg. of niacin was given. Another animal required 9 months to show a niacin deficiency and then grew adequately when only 6 mg. of niacin per week was furnished. This seems to show a several-fold range in niacin needs within a small group of fine animals. The tryptophane needs of the different monkeys, as judged by growth responses, were found to vary under comparable conditions from 1 to about 3.5 gm. per week. 

Ruze P. (1990). Kava-induced dermopathy a niacin deficiency Lancet. 335(8703) 1442-5. 

Niacin is found in many foods, including corn. The niacin in corn, however, cannot be absorbed in the intestinal tract. In regions of the world where corn is a major part of the diet, niacin deficiency can occur. If you add calcium oxide or wood ash to the water in which you boil corn, the resulting basic solution allows the niacin to be absorbed. The flour for making corn tortillas is commonly prepared using this method. 

Niacin, which refers to nicotinic acid and nicotinamide, is the metabolic precursor to three nicotinamide coenzymes. These are essential for the activity of a large number of enzymes catalyzing redox reactions. Pellagra is a niacin deficiency disease. 

Deficiency - Pellagra is a state of niacin deficiency characterized by dermatitis, diarrhea, and dementia (manifestations of mucous membranes, Gl system, and CNS). In severe cases, confusion, delusions, disorientation, and hallucinations may occur. 

Hartnup disorder exhibits symptoms similar to pellagra (niacin deficiency), characterized by three of the "four D s" diarrhea, dermatitis (a red, scaly rash), dementia (intermittent ataxia), and death... 

The answer is B. While all of the listed conditions are consistent with lethargy and developmental defects, the lactic acidosis rules out pyruvate kinase deficiency. Thiamine and niacin deficiencies are unlikely due to the lack of effect of vitamin supplementation. Excess pyruvate is the source of the elevated alanine in the serum. The clinical findings are thus consistent with pyruvate carboxylase deficiency, which is associated with severe hypoglycemia due to fasting due to impaired gluconeogenesis. 

Drug-induced niacin deficiency has resulted from the use of isonicotinic acid hydrazide, which interferes with the conversion of niacin from tryptophan. Administration of ethanol or the antimetabolites 6-mercaptop-urine and 5-fluorouracil also may lead to niacin deficiency. The uricosuric effects of sulfinpyrazone and probenecid may be inhibited by nicotinic acid. 

The typical Bg avitaminosis is very similar to riboflavine and niacin deficiency and is manifested by eye, mouth, and nose lesions as well as neurological symptoms. 

Deficiency symptoms In niacin deficiency, pellagra develops. The main... 

Nicotine forms a number of metabolites in the body, mainly in the liver. Approximate 75% of nicotine is oxidized to cotinine, which is the primary nicotine metabolite. Cotinine can be measured in the blood, urine, and saliva and this is used as a measure of nicotine exposure in tobacco users and in those exposed to secondhand smoke. The oxidation of nicotine also produces nicotinic acid. Nicotinic acid is vitamin B3 and has the common name niacin. Niacin deficiency results in a disease called pellagra, which is found in certain malnourished populations. Pellagras symptoms include dermatitis, diarrhea, sensitivity to light, and dementia. 

J. Z. Zhang, S. M. Henning, and M. E. Swendseid, Poly(ADP-ribose) Polymerase Activity and DNA Strand Breaks Are Affected in Tissues of Niacin-deficient Rats, J. Nutr. 123 (1993) 1349-55. 

The classical niacin deficiency disease is pellagra, which is characterized by symptoms including diarrhoea, dermatitis, dementia and eventually death. High-protein diets are rarely deficient in niacin since, in addition to the preformed vitamin, such diets supply sufficient tryptophan to meet dietary requirements. Large doses of niacin can cause the dilation of capillaries, resulting in a painful tingling sensation. 

Niacin deficiency is known to produce pellagra, which presents dermatological, gastrointestinal, and neurological symptoms (19,93,96). Niacin has also been implicated in several nonvitamin functions, which are still under investigation. These include the reduction of serum cholesterol levels, vasodilation, and modulation of the effects of cancer and diabetes (93,96-99). 

EL Jacobson. Niacin deficiency and cancer in women. J Am Coll Nutr 12 412-416, 1993. 

Pellagra, Niacin Deficiency. It was 220 years after the first description of pellagra that nicotinic acid was discovered to be the cure for black tongue in dogs (14), a condition suggested by a veterinarian in North Carolina to be similar to human pellagra (15). 

Vitamin B3 is a pyridine compound found in fish, meat, liver, cereal husks, nuts, and pulses. Niacin deficiency produces pellagra, which manifests as dermatitis, diarrhea with enteritis, nausea and vomiting, dementia with headache, insomnia, loss of memory, and disturbances of motor and sensory neurons. Anemia and hypoprotcincrnia are common in pellagra chronic alcoholics have more tendency to suffer from pellagra. Com eaters suffer from pellagra because com... 

Early 1900s Treatment of histamine shock, pellagra (niacin deficiency) and rickets (vitamin D deficiency) Electrocardiography and cardiac catheterization... 

Tryptophan provides some of the human daily niacin requirements. Hence niacin deficiency with pellagra-like symptoms develops if the diet contains insufficient amounts of tryptophan. 

Vitamin B3, also known as niacin, helps maintain the normal function of the skin, nerves, and digestive system. The disease pellagra results from a severe niacin deficiency. People with pellagra experience mouth sores, skin irritation, and mental deterioration. Niacin has the following formula C6H5N02. Often vitamin... 

After it had been established that pellagra was a nutritional deficiency disease, the next problem was to discover the missing nutrient. Additional dietary protein was shown to be beneficial, thus it was concluded that pellagra was because of a protein deficiency. This view, and later that it was more specifically from a deficiency of tryptophan, was held for some time. In 1938, Spies and coworkers showed that nicotinic acid would cure pellagra thereafter it was gradually accepted that it was a niacin deficiency disease. 

The best-established function of poly(ADP-ribose) polymerase is in repair of damaged DNA it is activated by DNA strand breaks, and acts to clear histones and other nucleoproteins away from the DNA to permit access of the DNA repair enzymes. Both in vitro and in experimental animals, niacin deficiency leads to increased genomic instability, as the ability to repair damaged DNA is impaired, and may increase tumor risk. There is little information about genomic instability and cancer risk in human niacin deficiency (ffageman and Stiemm, 200f). 

The role of cADP-ribose and NAADP in regulating cytosolic calcium may provide an alternative explanation to the serotonin hypothesis for the psychiatric and neurological signs of the niacin deficiency disease pellagra (Section 8.5 Petersen and Cancela, 1999). 

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