Riboflavin Deficiency in Man: A Preliminary Note

Sebrell, W. H.; Butler, R. E.

doi:10.2307/4582747

Cited by 137 publications

(15 citation statements)

References 5 publications

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“…In the present study of niacin requirement, diets were supplemented with other B vitamins and the lesions which developed can be attributed primarily to niacin deficiency. Cheilosis, angular stomatitis and dermatitis of the nasolabial folds, which have been produced in experimental riboflavin deficiency (23,24) and by the administration of desoxypyridoxine (25), were also observed in the present investigation. The occurrence of these lesions in pellagra has previously been attributed to concomitant riboflavin deficiency.…”

Section: Discussionsupporting

confidence: 49%

Studies of Niacin Requirement in Man. I. Experimental Pellagra in Subjects on Corn Diets Low in Niacin and Tryptophan 1

Goldsmith¹,

Sarett²,

et al. 1952

J. Clin. Invest.

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Early attempts to estimate human niacin requirement were based on calculations of the niacin content of pellagragenic and nonpellagragenic diets (1, 2). It was appreciated that the protein content of the diet was in some way related to niacin requirement. Recent studies showing that the amino acid tryptophan is converted in part to niacin compounds in man (3-5) may explain the above relationship, and also the pellagra preventive effect of foods which are low in niacin but rich in "good" protein.The present experiments were designed to study niacin requirement in man with diets of known tryptophan content. Estimation of minimum tryptophan requirement for nitrogen balance (6) permits formulation of diets containing little excess tryptophan which may be converted to niacin. The discovery of the major metabolites of niacin, namely Nl-methylnicotinamide (N'-Me) and the 6-pyridone of Nl-methylnicotinamide (pyridone), and the development of methods for the measurement of these compounds in urine, now permit more complete studies of niacin metabolism (7-11).Seven subjects were maintained on diets low in niacin and tryptophan for from 40 to 135 days and the urinary excretion of niacin metabolites was determined. Clinical signs of pellagra developed in the three subjects who remained on one of these diets for more than 50 days. METHODSThe seven subjects were white females, 25 to 54 years of age, who were found to be essentially free of organic ',This work was supported by grants from the Nutri- The diet for two complete days was analyzed at intervals for niacin, tryptophan and total nitrogen. The diet for each meal was blended with water in a Waring blendor to give a total volume of 1,000 to 1,500 ml. Aliquots of this material were autoclaved in 1 N sulfuric acid solution for 45 minutes, neutralized and analyzed for niacin microbiologically, using L. arabinosus (12). This organism was also employed for tryptophan analysis using aliquots of the homogenate which had been autoclaved in 5 N sodium hydroxide in the presence of cysteine (13). For these analyses 15 ml. portions of 8 N sodium hydroxide solution were placed in 125 ml. Erlenmeyer flasks and 400 mg. of cysteine and 10 ml. of the blended diet were rapidly added. These were covered at once with beakers and autoclaved for six hours at 1210 C.After neutralization with hydrochloric acid, the solutions were diluted to 100 ml., filtered and analyzed. Under these conditions it is assumed that all tryptophan. liberated from the proteins was racemized and was present as D,L-tryptophan. Although it is possible that some tryptophan in the proteins may have been destroyed by this procedure, L-or D,L-tryptophan added to the samples was not destroyed and treatment of L-or D,L-tryptophan alone with these reagents resulted in 90 to 100% recovery. Analyses of the diets and of individual foods gave reproducible results. Nitrogen was determined by the macro-Kjeldahl method.All urine was collected for 24 hour periods in dark bottles containing 5 ml. of glacial acetic acid and kept in th...

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Section: Discussionsupporting

confidence: 49%

Studies of Niacin Requirement in Man. I. Experimental Pellagra in Subjects on Corn Diets Low in Niacin and Tryptophan 1

Goldsmith¹,

Sarett²,

et al. 1952

J. Clin. Invest.

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“…The involved substrates include glucose, lactic acid, the d-amino acids, and other compounds of biological interest (1,2,3). Riboflavin deficiency has been described in man (4), and it seems possible that further clinical study of this vitamin may reveal alterations in its metabolism which will increase our knowledge of the r6le played by these enzymatic oxidation systems in health and in disease. To aid in interpreting such a study, a convenient method has been sought for following the urinary excretion of riboflavin.…”

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confidence: 99%

The Urinary Excretion of Riboflavin Fluorometric Methods for Its Estimation

Ferrebee¹

1940

J. Clin. Invest.

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Riboflavin, vitamin B2, serves in its phosphorylated form as the prosthetic group for a number of tissue enzymes important in biological oxidations (1). The involved substrates include glucose, lactic acid, the d-amino acids, and other compounds of biological interest (1, 2, 3). Riboflavin deficiency has been described in man (4), and it seems possible that further clinical study of this vitamin may reveal alterations in its metabolism which will increase our knowledge of the r6le played by these enzymatic oxidation systems in health and in disease. To aid in interpreting such a study, a convenient method has been sought for following the urinary excretion of riboflavin.It is known that riboflavin occurs in urine in the form of uroflavin, a pigment almost identical with it in composition,' properties, and vitamin activity (5), but the methods usually recommended for its determination (5,6,7,8,9) were not found by the writer to be sufficiently convenient or accurate for routine use. More specific and accurate determinations are possible, and smaller and more convenient volumes of urine (I to 10 cc. instead of 100 to 500 cc.) can be used when the pigment is estimated not by its optical density but by its intense greenish-yellow fluorescence.2 In order to do this, the effect of interfering substances must be avoided. With urines of normal individuals containing 0.5 gamma or more flavin per cc., this is readily accomplished by diluting down the salts and other materials to the point where they no longer affect fluorescence (10) and by destroying the greater part of other pig-1 The carbon analysis of the purest preparation isolated did not quite agree with that for riboflavin (Koschara (5)).2 Pfaltz & Bauer, New York City. Model A is a suitable fluorometer provided with an additional cell for the measurement of optical density. ments and fluorescent materials in a brief permanganate toxidation (5). With urines of certain patients containing less than 0.5 gamma per cc., some preliminary concentration of the uroflavin is necessary, and can be much more conveniently and effectively carried out by using an adsorption column than by adding large quantities of adsorbing agent directly to urine (11,12). In measuring the fluorescence of the column eluates or the diluted urine samples, the usual ultra violet radiation is not satisfactory since it excites the fluorescence of too many substances. Measurements of flavin fluorescence are much more specific and much more accurate when carried out with an exciting beam of visual wavelength, Mercury line at 4358A°, and when the fluorometric photoelectric cell is protected by a yellow filter.3 With such an arrangement, the relationship between fluorescence and riboflavin concentration is linear for column eluates and diluted urine samples (Figures 1 and 2), particularly when the effect of any occasional alteration in optical density is corrected by means of the empirical curve illustrated in Figure 3. METHODS

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“…Such cases were given the paradoxical label " pellagra sine pellagra." Sebrell and Butler's (1938) later identification of the syndrome of ariboflavinosis accounted for the vast majority of these cases. Peters's hypothesis should go a long way to account for the rest.…”

Section: Discussionmentioning

confidence: 99%

Deficiency Patterns in Metallic Poisoning

Hughes¹

1950

BMJ

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Riboflavin Deficiency in Man: A Preliminary Note

Cited by 137 publications

References 5 publications

Studies of Niacin Requirement in Man. I. Experimental Pellagra in Subjects on Corn Diets Low in Niacin and Tryptophan 1

Studies of Niacin Requirement in Man. I. Experimental Pellagra in Subjects on Corn Diets Low in Niacin and Tryptophan 1

The Urinary Excretion of Riboflavin Fluorometric Methods for Its Estimation

Deficiency Patterns in Metallic Poisoning

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