Deficiency
Niacin (nicotinic acid) deficiency classically results in pellagra, which is a chronic wasting disease associated with a characteristic erythematous dermatitis that is bilateral and symmetrical, a dementia after mental changes including insomnia and apathy preceding an overt encephalopathy, and diarrhoea resulting from inflammation of the intestinal mucous surfaces. At present, pellagra occurs endemically in poorer areas. Its cause has been mainly attributed to a deficiency of niacin; however, its biochemical inter-relationship to riboflavin and vitamin B6, which are needed for the conversion of L-tryptophan to niacin equivalents (NEs), suggests that insufficiencies of these vitamins may also contribute to pellagra. Pellagra-like syndromes occurring in the absence of a dietary niacin deficiency are also attributable to disturbances in tryptophan metabolism (e.g., Hartnup disease with impaired absorption of the amino acid and carcinoid syndrome where the major catabolic pathway routes to 5-hydroxytryptophan). Pellagra also occurs in people with chronic alcoholism. Cases of niacin deficiency have been found in people suffering from Crohn’s disease.
Toxicity
Although therapeutically useful in lowering serum cholesterol, administration of chronic high oral doses of nicotinic acid can lead to hepatotoxicity as well as dermatologic manifestations. An upper limit (UL) of 35 mg/day as proposed by the US Food and Nutrition Board was
adopted by this consultation.
Functions
Niacin is chemically synonymous with nicotinic acid although the term is also used for its amide (nicotinamide). Nicotinamide is the other form of the vitamin, which does not have the pharmacologic action of the acid that is administered at high doses to lower blood lipids. It is the amide form that exists within the redox-active co-enzymes, nicotinamide adenine dinucleotide (NAD) and its phosphate (NADP), which function in dehydrogenase-reductase systems requiring transfer of a hydride ion. NAD is also required for non-redox adenosine diphosphate–ribose transfer reactions involved in DNA repair and calcium mobilisation. NAD functions in intracellular respiration and with enzymes involved in the oxidation of fuel substrates such as glyceraldehyde 3-phosphate, lactate, alcohol, 3- hydroxybutyrate, and pyruvate. NADP functions in reductive biosyntheses such as fatty acid and steroid syntheses and in the oxidation of glucose-6-phosphate to ribose-5-phosphate in the pentose phosphate pathway.
Biochemical indicators
Indicators used to estimate niacin requirements are urinary excretion, plasma concentrations of metabolites, and erythrocyte pyridine nucleotides. The excretion rate of metabolites, mainly N'-methyl-nicotinamide and its 2- and 4-pyridones, reflects intake and is usually expressed as a ratio of the pyridones to N'-methyl-nicotinamide. Concentrations of metabolites, especially 2-pyridone, are measured in plasma after a load test. Erythrocyte pyridine nucleotides measure NAD concentration changes.
Niacin status has been monitored by daily urinary excretion of methylated metabolites, especially the ratio of the 2-pyridone to N'-methyl-nicotinamide; erythrocyte pyridine nucleotides; oral dose uptake tests; erythrocyte NAD; and plasma 2-pyridone. Shibata and Matsuo found that the ratio of urinary 2-pyridone to N'-methyl-nicotinamide was as much a measure of protein adequacy as it was a measure of niacin status. Jacob et al. found this ratio too insensitive to marginal niacin intake.
The ratio of the 2-pyridone to N'- methyl-nicotinamide also appears to be associated with the clinical symptoms of pellagra, principally the dermatitic condition. In plasma, 2-pyridone levels change in reasonable proportion to niacin intake. Similarly to the situation for erythrocyte pyridine nucleotide (nicotinamide co-enzymes), NAD concentration decreased 70 percent whereas NADP remained unchanged in adult males fed diets with only 6 or 10 mg NEs/day. Erythrocyte NAD provided a marker at least as sensitive as urinary metabolites of niacin in this study and in a niacin depletion study of elderly subjects.
Factors affecting requirements
The biosynthesis of niacin derivatives on the pathway to nicotinamide co-enzymes stems from tryptophan, an essential amino acid found in protein, and as such this source of NEs increases niacin intake. There are several dietary, drug, and disease factors that reduce the conversion of tryptophan to niacin (e.g. the use of oral contraceptives. Although a 60-to-1 conversion factor represents the average for human utilisation of tryptophan as NEs, there are substantial individual differences. There is also an interdependence of enzymes within the tryptophan-to-niacin pathway where vitamin B6 (as pyridoxal phosphate) and riboflavin (as FAD) are functional. Further, riboflavin (as FMN) is required for the oxidase that forms coenzymic PLP from the alcohol and amine forms of phosphorylated vitamin B6.
Findings by age and life stage
Niacin content of human milk is approximately 1.5 mg (12.3 μmol) /l and the tryptophan content is 210 mg (1.0mmol) /l. Hence, the total content is approximately 5 mg NEs/l or 4 mg NEs/ 0.75 l secreted daily in human milk. Recent studies together with those reported in the 1950s suggest that 12.5 mg NEs, which corresponds to 5.6 mg NEs/4184 kJ, is minimally sufficient for niacin intake in adults.
For pregnant women, where 230 MJ is the estimated energy cost of pregnancy, calculated needs above those of non-pregnant women are 5.6 mg NEs/ 4186 kjoule (1,000 kcal) × 230,000 kjoule (55,000 kcal), or 308 mg NEs for the entire pregnancy or 1.7 mg NEs/day (308 mg NEs/180 days) for the second and third trimester, which is about a 10 percent increase. Also about 2 mg NEs/day is required for growth in maternal and foetal compartments. For lactating women, an estimated 1.4 mg preformed niacin is secreted daily, and an additional requirement of less than 1 mg is needed to support the energy expenditure of lactation. Hence, 2.4 mg NEs/day is the added need attributable to lactation.
References:
Food and Nutrition Board, Institute of Medicine/National Academy of Sciences- National Research Council. 1998. Dietary Reference Intake: Folate, Other B Vitamins, and Choline. Washington, D.C., National Academy Press.
McCormick, D.B. 1997. Vitamin, Structure and Function of. In: Encyclopedia of Molecular Biology and Molecular Medicine, Vol. 6. Meyers, R.A., ed. Weinheim: VCH,
p. 244-52.
McCormick, D.B & Greene, H.L. 1994. Vitamins. In: Tietz Textbook of Clin Chem., 2nd
edition. Burtis, V.A., Ashwood, E.R., eds. Philadelphia: W.B. Saunders, p. 1275-1316.
Committee on Nutrition. 1985. Composition of Human milk: normative data. In: Pediatric Nutrition Handbook, 2nd Edition. Elk Grove Village, IL: Am. Acad. Pediatr., p.363-368.
Wyatt, D.T., Nelson, D. & Hillman, R.E. 1991. Age-dependent changes in thiamin concentrations in whole blood and cerebrospinal fluid in infants and children. Am. J. Clin. Nutr., 53: 530-6.
Sauberlich, H.E., Herman, Y.F., Stevens, C.O. & Herman, R.H. 1979. Thiamin
requirement of the adult Human. Am. J. Clin. Nutr., 32: 2237-48.
Wood, B., Gijsbers, A., Goode, A., Davis, S., Mulholland, J. & Breen, K. 1980. A
study of partial thiamin restriction in Human volunteers. Am. J. Clin. Nutr., 33: 848-61.
Anderson, S. H., Charles, T.J. & Nicol, A.D. 1985. Thiamine deficiency at a district
general hospital: report of five cases. Q. J. Med., 55: 15-32.
Hoorn, R.K., Flikweert, J.P. & Westerink, D. 1975. Vitamin B1, B2 and B6 deficiencies in geriatric patients, measured by co-enzyme stimulation of enzyme activities. Clinica Chimica Acta, 61: 151-62.
Nichols, H.K. & Basu, T.K. 1994. Thiamin status of the elderly: dietary intake and thiamin pyrophosphate response. J. Am. Coll. Nutr., 13: 57-61.
Food and Nutrition Board, Institute of Medicine/National Academy of Sciences- National Research Council. 1990. Nutrition During Pregnancy. Part I Weight Gain. Part II Nutrient Supplements. Washington, D.C, National Academy Press.
McCormick, D.B. 1994. Riboflavin. In: Modern Nutrition in Health and Disease, 8th edition. Shils, M.E., Olson, J.A., Shike, M., eds. Philadelphia: Lea & Febiger, p. 366-75.
Smith, M.D. 1980. Rapid method for determination of riboflavin in urine by highperformance liquid chromatography. J. Chromatogr., 182: 285-91.
Chastain, J.L. & McCormick, D.B. 1987. Flavin catabolites: identification and quantitation in Human urine. Am. J. Clin. Nutr., 46: 830-4.
Roughead, Z.K. & McCormick, D.B. 1991. Urinary riboflavin and its metabolites: effects of riboflavin supplementation in healthy residents of rural Georgia (USA). Eur. J. Clin. Nutr., 45: 299-307.
Aw, T.-Y., Jones, D.P. & McCormick, D.B. 1983. Uptake of riboflavin by isolated rat liver cells. J. Nutr., 113: 1249-54.
Nichoalds, G.E. 1981. Riboflavin. Symposium in Laboratory Medicine. In: Labbac RF, ed. Symposium on Laboratory Assessment of Nutritional Status. Clinics in Laboratory Medicine. Philadelphia: W.B. Saunders, 1: 685-98.
Sadowski, J.A. 1992. Riboflavin. In: Nutrition in the Elderly. The Boston Nutritional Status Survey. Hartz, S.C., Russell, R.M., Rosenberg, I.H. eds. London: Smith-Gordon, p. 119-25.
Ramsay, V.P., Neumann, C., Clark, V. & Swenseid, M.E. 1983. Vitamin cofactor saturation indices for riboflavin, thiamine, and pyridoxine in placental tissue of Kenyan women. Am. J. Clin. Nutr., 37: 969-73.
Belko, A.Z., Obarzanek, E., Kalkwarf, H.J., Rotter, M.A., Bogusz, S., Miller, D., Haas, J.D. & Roe, D.A. 1983. Effects of exercise on riboflavin requirements of young women. Am. J. Clin. Nutr., 37: 509-17.
Belko, A.Z., Obarzanek, E., Roach, R., Rotten, M., Urban, G., Weinberg, S. & Roe, D.A. 1984. Effects of aerobic exercise and weight loss on riboflavin requirements of moderately obese, marginally deficient young women. Am. J. Clin. Nutr., 40: 553-61.
Belko, A.Z., Meredith, M.P., Kalkwarf, H.J., Obarzanek, E., Weinberg, S., Roach, R., McKeon, G. & Roe, D.A. 1985. Effects of exercise on riboflavin requirements: biological validation in weight reducing women. Am. J. Clin. Nutr., 41: 270-7.
Soares, M.J., Satyanarayana, K., Bamji, M.S., Jacob, C.M., Ramana, Y.V. & Rao,
S.S. 1993. The effect of exercise on the riboflavin status of adult men. Br. J. Nutr., 69: 541-51.
Winters, L.R., Yoon, J.S., Kalkwarf, H.J., Davies, J.C., Berkowitz, M.G., Haas, J. & Roe, D.A. 1992. Riboflavin requirements and exercise adaptation in older women. Am. J. Clin. Nutr., 56: 526-32.
Powers, H.J., Bates, C.J., Eccles, M., Brown, H. & George, E. 1987. Bicycling performance in Gambian children: effects of supplements of riboflavin or ascorbic acid. Human. J. Clin. Nutr., 41: 59-69.
Prasad, A.P., Bamji, M.S., Lakshmi, A.V. & Satyanarayana, K. 1990. Functional impact of riboflavin supplementation in urban school children. Nutr Res., 10: 275-81.
Tremblay, A., Boilard, M., Bratton, M.F., Bessette, H. & Roberge, A.B. 1984. The
effects of a riboflavin supplementation on the nutritional status and performance of elite swimmers. Nutr Res., 4: 201-8.
Weight, L.M., Myburgh, K.H. & Noakes, T.D. 1988. Vitamin and mineral supplementation: effect on the running performance of trained athletes. Am. J. Clin. Nutr., 47: 192-5.
Zempleni, J., Galloway, J.R. & McCormick, D.B. 1996. Pharmacokinetics of orally and intravenously administered riboflavin in healthy Humans. Am. J. Clin. Nutr., 63: 54-66.
Chia, C.P., Addison, R. & McCormick, D.B. 1978. Absorption, metabolism, and excretion of 8a-(amino acid)-riboflavins in the rat. J. Nutr., 108: 373-81.
Boisvert, W.A., Mendoza, I., Castañeda, C., DePortocarrero, L., Solomons, N.W., Gershoff, S.N. & Russell, R.M. 193. Riboflavin requirement of healthy elderly Humans and its relationship to macronutrient composition of the diet. J. Nutr., 123: 915-25.
McCormick, D.B. 1989. Two interconnected B vitamins: riboflavin and pyridoxine. Physiol. Revs., 69: 1170-98.
McCormick, D.B. 1988. Niacin. In: Modern Nutrition in Health and Disease, 6th edition.
Shils, M.E., Young, V.R., eds. Philadelphia: Lea & Febiger, 370-5.
Carpenter, K.J. & Lewin, W.J. 1985. A reexamination of the composition of diets associated with pellagra. J. Nutr., 115: 543-52.
Berger, N.A. 1985. Poly(ADP-ribose) in the cellular response to DNA damage. Radiat. Res., 101: 4-15.
Shibata, K. & Matsuo, H. 1989. Effect of supplementing low protein diets with the limiting amino acids on the excretion of N1-methylnicotinamide and its pyridones in rat. J. Nutr., 119: 896-901.
Jacob, R.A., Swendseid, M.E., McKee, R.W., Fu, C.S. & Clemens, R.A. 1989.
Biochemical markers for assessment of niacin status in young men: urinary and blood
levels of niacin metabolites. J. Nutr., 119: 591-8.
66. Dillon, J.C., Malfait, P., Demaux, G. & Foldi-Hope, C. 1992. The urinary metabolites of niacin during the course of pellagra. Ann. Nutr. Metab., 36: 181-5.
Fu, C.S., Swendseid, M.E., Jacob, R.A. & McKee, R.W. 1989. Biochemical markers for assessment of niacin status in young men: levels of erythrocyte niacin co-enzymes and plasma tryptophan. J. Nutr., 119: 1949-55.
Ribaya-Mercado. J.D., Russell, R.M., Rasmussen, H.M., Crim, M.C., Perrone-Petty, G. & Gershoff, S.N. 1997. Effect of niacin status on gastrointestinal function and serum lipids. FASEB J., 11: A179 abstract.
Rose, D.P. & Braidman, I.P. 1971. Excretion of tryptophan metabolites as affected by pregnancy, contraceptive steroids, and steroid hormones. Am. J. Clin. Nutr., 24: 673-83.
Patterson, J.I., Brown, R.R., Linkswiler, H. & Harper, A.E. 1980. Excretion of tryptophan-niacin metabolites by young men: effects of tryptophan, leucine, and vitamin
B6 intakes. Am. J. Clin. Nutr., 33: 2157-67.
Horwitt, M.K., Harper, A.E. & Henderson, L.M. 1981. Niacin-tryptophan relationships for evaluating for evaluating niacin equivalents. Am. J. Clin. Nutr., 34: 423-7.
Toxicity
Although therapeutically useful in lowering serum cholesterol, administration of chronic high oral doses of nicotinic acid can lead to hepatotoxicity as well as dermatologic manifestations. An upper limit (UL) of 35 mg/day as proposed by the US Food and Nutrition Board was
adopted by this consultation.
Functions
Niacin is chemically synonymous with nicotinic acid although the term is also used for its amide (nicotinamide). Nicotinamide is the other form of the vitamin, which does not have the pharmacologic action of the acid that is administered at high doses to lower blood lipids. It is the amide form that exists within the redox-active co-enzymes, nicotinamide adenine dinucleotide (NAD) and its phosphate (NADP), which function in dehydrogenase-reductase systems requiring transfer of a hydride ion. NAD is also required for non-redox adenosine diphosphate–ribose transfer reactions involved in DNA repair and calcium mobilisation. NAD functions in intracellular respiration and with enzymes involved in the oxidation of fuel substrates such as glyceraldehyde 3-phosphate, lactate, alcohol, 3- hydroxybutyrate, and pyruvate. NADP functions in reductive biosyntheses such as fatty acid and steroid syntheses and in the oxidation of glucose-6-phosphate to ribose-5-phosphate in the pentose phosphate pathway.
Biochemical indicators
Indicators used to estimate niacin requirements are urinary excretion, plasma concentrations of metabolites, and erythrocyte pyridine nucleotides. The excretion rate of metabolites, mainly N'-methyl-nicotinamide and its 2- and 4-pyridones, reflects intake and is usually expressed as a ratio of the pyridones to N'-methyl-nicotinamide. Concentrations of metabolites, especially 2-pyridone, are measured in plasma after a load test. Erythrocyte pyridine nucleotides measure NAD concentration changes.
Niacin status has been monitored by daily urinary excretion of methylated metabolites, especially the ratio of the 2-pyridone to N'-methyl-nicotinamide; erythrocyte pyridine nucleotides; oral dose uptake tests; erythrocyte NAD; and plasma 2-pyridone. Shibata and Matsuo found that the ratio of urinary 2-pyridone to N'-methyl-nicotinamide was as much a measure of protein adequacy as it was a measure of niacin status. Jacob et al. found this ratio too insensitive to marginal niacin intake.
The ratio of the 2-pyridone to N'- methyl-nicotinamide also appears to be associated with the clinical symptoms of pellagra, principally the dermatitic condition. In plasma, 2-pyridone levels change in reasonable proportion to niacin intake. Similarly to the situation for erythrocyte pyridine nucleotide (nicotinamide co-enzymes), NAD concentration decreased 70 percent whereas NADP remained unchanged in adult males fed diets with only 6 or 10 mg NEs/day. Erythrocyte NAD provided a marker at least as sensitive as urinary metabolites of niacin in this study and in a niacin depletion study of elderly subjects.
Factors affecting requirements
The biosynthesis of niacin derivatives on the pathway to nicotinamide co-enzymes stems from tryptophan, an essential amino acid found in protein, and as such this source of NEs increases niacin intake. There are several dietary, drug, and disease factors that reduce the conversion of tryptophan to niacin (e.g. the use of oral contraceptives. Although a 60-to-1 conversion factor represents the average for human utilisation of tryptophan as NEs, there are substantial individual differences. There is also an interdependence of enzymes within the tryptophan-to-niacin pathway where vitamin B6 (as pyridoxal phosphate) and riboflavin (as FAD) are functional. Further, riboflavin (as FMN) is required for the oxidase that forms coenzymic PLP from the alcohol and amine forms of phosphorylated vitamin B6.
Findings by age and life stage
Niacin content of human milk is approximately 1.5 mg (12.3 μmol) /l and the tryptophan content is 210 mg (1.0mmol) /l. Hence, the total content is approximately 5 mg NEs/l or 4 mg NEs/ 0.75 l secreted daily in human milk. Recent studies together with those reported in the 1950s suggest that 12.5 mg NEs, which corresponds to 5.6 mg NEs/4184 kJ, is minimally sufficient for niacin intake in adults.
For pregnant women, where 230 MJ is the estimated energy cost of pregnancy, calculated needs above those of non-pregnant women are 5.6 mg NEs/ 4186 kjoule (1,000 kcal) × 230,000 kjoule (55,000 kcal), or 308 mg NEs for the entire pregnancy or 1.7 mg NEs/day (308 mg NEs/180 days) for the second and third trimester, which is about a 10 percent increase. Also about 2 mg NEs/day is required for growth in maternal and foetal compartments. For lactating women, an estimated 1.4 mg preformed niacin is secreted daily, and an additional requirement of less than 1 mg is needed to support the energy expenditure of lactation. Hence, 2.4 mg NEs/day is the added need attributable to lactation.
References:
Food and Nutrition Board, Institute of Medicine/National Academy of Sciences- National Research Council. 1998. Dietary Reference Intake: Folate, Other B Vitamins, and Choline. Washington, D.C., National Academy Press.
McCormick, D.B. 1997. Vitamin, Structure and Function of. In: Encyclopedia of Molecular Biology and Molecular Medicine, Vol. 6. Meyers, R.A., ed. Weinheim: VCH,
p. 244-52.
McCormick, D.B & Greene, H.L. 1994. Vitamins. In: Tietz Textbook of Clin Chem., 2nd
edition. Burtis, V.A., Ashwood, E.R., eds. Philadelphia: W.B. Saunders, p. 1275-1316.
Committee on Nutrition. 1985. Composition of Human milk: normative data. In: Pediatric Nutrition Handbook, 2nd Edition. Elk Grove Village, IL: Am. Acad. Pediatr., p.363-368.
Wyatt, D.T., Nelson, D. & Hillman, R.E. 1991. Age-dependent changes in thiamin concentrations in whole blood and cerebrospinal fluid in infants and children. Am. J. Clin. Nutr., 53: 530-6.
Sauberlich, H.E., Herman, Y.F., Stevens, C.O. & Herman, R.H. 1979. Thiamin
requirement of the adult Human. Am. J. Clin. Nutr., 32: 2237-48.
Wood, B., Gijsbers, A., Goode, A., Davis, S., Mulholland, J. & Breen, K. 1980. A
study of partial thiamin restriction in Human volunteers. Am. J. Clin. Nutr., 33: 848-61.
Anderson, S. H., Charles, T.J. & Nicol, A.D. 1985. Thiamine deficiency at a district
general hospital: report of five cases. Q. J. Med., 55: 15-32.
Hoorn, R.K., Flikweert, J.P. & Westerink, D. 1975. Vitamin B1, B2 and B6 deficiencies in geriatric patients, measured by co-enzyme stimulation of enzyme activities. Clinica Chimica Acta, 61: 151-62.
Nichols, H.K. & Basu, T.K. 1994. Thiamin status of the elderly: dietary intake and thiamin pyrophosphate response. J. Am. Coll. Nutr., 13: 57-61.
Food and Nutrition Board, Institute of Medicine/National Academy of Sciences- National Research Council. 1990. Nutrition During Pregnancy. Part I Weight Gain. Part II Nutrient Supplements. Washington, D.C, National Academy Press.
McCormick, D.B. 1994. Riboflavin. In: Modern Nutrition in Health and Disease, 8th edition. Shils, M.E., Olson, J.A., Shike, M., eds. Philadelphia: Lea & Febiger, p. 366-75.
Smith, M.D. 1980. Rapid method for determination of riboflavin in urine by highperformance liquid chromatography. J. Chromatogr., 182: 285-91.
Chastain, J.L. & McCormick, D.B. 1987. Flavin catabolites: identification and quantitation in Human urine. Am. J. Clin. Nutr., 46: 830-4.
Roughead, Z.K. & McCormick, D.B. 1991. Urinary riboflavin and its metabolites: effects of riboflavin supplementation in healthy residents of rural Georgia (USA). Eur. J. Clin. Nutr., 45: 299-307.
Aw, T.-Y., Jones, D.P. & McCormick, D.B. 1983. Uptake of riboflavin by isolated rat liver cells. J. Nutr., 113: 1249-54.
Nichoalds, G.E. 1981. Riboflavin. Symposium in Laboratory Medicine. In: Labbac RF, ed. Symposium on Laboratory Assessment of Nutritional Status. Clinics in Laboratory Medicine. Philadelphia: W.B. Saunders, 1: 685-98.
Sadowski, J.A. 1992. Riboflavin. In: Nutrition in the Elderly. The Boston Nutritional Status Survey. Hartz, S.C., Russell, R.M., Rosenberg, I.H. eds. London: Smith-Gordon, p. 119-25.
Ramsay, V.P., Neumann, C., Clark, V. & Swenseid, M.E. 1983. Vitamin cofactor saturation indices for riboflavin, thiamine, and pyridoxine in placental tissue of Kenyan women. Am. J. Clin. Nutr., 37: 969-73.
Belko, A.Z., Obarzanek, E., Kalkwarf, H.J., Rotter, M.A., Bogusz, S., Miller, D., Haas, J.D. & Roe, D.A. 1983. Effects of exercise on riboflavin requirements of young women. Am. J. Clin. Nutr., 37: 509-17.
Belko, A.Z., Obarzanek, E., Roach, R., Rotten, M., Urban, G., Weinberg, S. & Roe, D.A. 1984. Effects of aerobic exercise and weight loss on riboflavin requirements of moderately obese, marginally deficient young women. Am. J. Clin. Nutr., 40: 553-61.
Belko, A.Z., Meredith, M.P., Kalkwarf, H.J., Obarzanek, E., Weinberg, S., Roach, R., McKeon, G. & Roe, D.A. 1985. Effects of exercise on riboflavin requirements: biological validation in weight reducing women. Am. J. Clin. Nutr., 41: 270-7.
Soares, M.J., Satyanarayana, K., Bamji, M.S., Jacob, C.M., Ramana, Y.V. & Rao,
S.S. 1993. The effect of exercise on the riboflavin status of adult men. Br. J. Nutr., 69: 541-51.
Winters, L.R., Yoon, J.S., Kalkwarf, H.J., Davies, J.C., Berkowitz, M.G., Haas, J. & Roe, D.A. 1992. Riboflavin requirements and exercise adaptation in older women. Am. J. Clin. Nutr., 56: 526-32.
Powers, H.J., Bates, C.J., Eccles, M., Brown, H. & George, E. 1987. Bicycling performance in Gambian children: effects of supplements of riboflavin or ascorbic acid. Human. J. Clin. Nutr., 41: 59-69.
Prasad, A.P., Bamji, M.S., Lakshmi, A.V. & Satyanarayana, K. 1990. Functional impact of riboflavin supplementation in urban school children. Nutr Res., 10: 275-81.
Tremblay, A., Boilard, M., Bratton, M.F., Bessette, H. & Roberge, A.B. 1984. The
effects of a riboflavin supplementation on the nutritional status and performance of elite swimmers. Nutr Res., 4: 201-8.
Weight, L.M., Myburgh, K.H. & Noakes, T.D. 1988. Vitamin and mineral supplementation: effect on the running performance of trained athletes. Am. J. Clin. Nutr., 47: 192-5.
Zempleni, J., Galloway, J.R. & McCormick, D.B. 1996. Pharmacokinetics of orally and intravenously administered riboflavin in healthy Humans. Am. J. Clin. Nutr., 63: 54-66.
Chia, C.P., Addison, R. & McCormick, D.B. 1978. Absorption, metabolism, and excretion of 8a-(amino acid)-riboflavins in the rat. J. Nutr., 108: 373-81.
Boisvert, W.A., Mendoza, I., Castañeda, C., DePortocarrero, L., Solomons, N.W., Gershoff, S.N. & Russell, R.M. 193. Riboflavin requirement of healthy elderly Humans and its relationship to macronutrient composition of the diet. J. Nutr., 123: 915-25.
McCormick, D.B. 1989. Two interconnected B vitamins: riboflavin and pyridoxine. Physiol. Revs., 69: 1170-98.
McCormick, D.B. 1988. Niacin. In: Modern Nutrition in Health and Disease, 6th edition.
Shils, M.E., Young, V.R., eds. Philadelphia: Lea & Febiger, 370-5.
Carpenter, K.J. & Lewin, W.J. 1985. A reexamination of the composition of diets associated with pellagra. J. Nutr., 115: 543-52.
Berger, N.A. 1985. Poly(ADP-ribose) in the cellular response to DNA damage. Radiat. Res., 101: 4-15.
Shibata, K. & Matsuo, H. 1989. Effect of supplementing low protein diets with the limiting amino acids on the excretion of N1-methylnicotinamide and its pyridones in rat. J. Nutr., 119: 896-901.
Jacob, R.A., Swendseid, M.E., McKee, R.W., Fu, C.S. & Clemens, R.A. 1989.
Biochemical markers for assessment of niacin status in young men: urinary and blood
levels of niacin metabolites. J. Nutr., 119: 591-8.
66. Dillon, J.C., Malfait, P., Demaux, G. & Foldi-Hope, C. 1992. The urinary metabolites of niacin during the course of pellagra. Ann. Nutr. Metab., 36: 181-5.
Fu, C.S., Swendseid, M.E., Jacob, R.A. & McKee, R.W. 1989. Biochemical markers for assessment of niacin status in young men: levels of erythrocyte niacin co-enzymes and plasma tryptophan. J. Nutr., 119: 1949-55.
Ribaya-Mercado. J.D., Russell, R.M., Rasmussen, H.M., Crim, M.C., Perrone-Petty, G. & Gershoff, S.N. 1997. Effect of niacin status on gastrointestinal function and serum lipids. FASEB J., 11: A179 abstract.
Rose, D.P. & Braidman, I.P. 1971. Excretion of tryptophan metabolites as affected by pregnancy, contraceptive steroids, and steroid hormones. Am. J. Clin. Nutr., 24: 673-83.
Patterson, J.I., Brown, R.R., Linkswiler, H. & Harper, A.E. 1980. Excretion of tryptophan-niacin metabolites by young men: effects of tryptophan, leucine, and vitamin
B6 intakes. Am. J. Clin. Nutr., 33: 2157-67.
Horwitt, M.K., Harper, A.E. & Henderson, L.M. 1981. Niacin-tryptophan relationships for evaluating for evaluating niacin equivalents. Am. J. Clin. Nutr., 34: 423-7.
No comments:
Post a Comment