VITAMIN B6 AND MENTAL DEFICIENCY: THE EFFECTS OF LARGE DOSES OF B6 (PYRIDOXINE) IN PHENYLKETONURIA

1959 ◽  
Vol 37 (1) ◽  
pp. 485-491
Author(s):  
Edith G. McGeer ◽  
Bluma Tischler

Vitamin B6 was given to 10 phenylketonuric patients in doses up to 150 mg/day for a period of 9 weeks. Their clinical signs, behavior, intelligence, E.E.G.('s), serum phenylalanine levels, urinary phenylpyruvic acid and phenol levels, and excretions of ethyl-acetate-soluble aromatic derivatives were followed serially. No changes of significance to phenylketonuria were found, although chromatographic evidence indicated some changes in excretion of a few aromatic derivatives, notably Nα-acetyltryptophan.


1959 ◽  
Vol 37 (3) ◽  
pp. 485-491 ◽  
Author(s):  
Edith G. McGeer ◽  
Bluma Tischler

Vitamin B6 was given to 10 phenylketonuric patients in doses up to 150 mg/day for a period of 9 weeks. Their clinical signs, behavior, intelligence, E.E.G.('s), serum phenylalanine levels, urinary phenylpyruvic acid and phenol levels, and excretions of ethyl-acetate-soluble aromatic derivatives were followed serially. No changes of significance to phenylketonuria were found, although chromatographic evidence indicated some changes in excretion of a few aromatic derivatives, notably Nα-acetyltryptophan.



1987 ◽  
Vol 44 (1) ◽  
pp. 219-222 ◽  
Author(s):  
Ronald W. Hardy ◽  
Edmundo Casillas ◽  
Toshiro Masumoto

Rainbow trout (Salmo gairdneri), initially averaging 125 g, were fed a complete or a pyridoxine-deficient diet for 14 wk. Vitamin B6 status was evaluated biweekly by direct measurement of liver pyridoxine and pyridoxal levels by HPLC and by determining pyridoxal-5′-phosphate-enhanced liver aspartate aminotransferase (ASAT) activity. By 14 wk, mortality had severely reduced the number of fish remaining in the pyridoxine-deficient group. At 14 wk, no significant differences in liver pyridoxine and pyridoxal levels were detected between the trout fed the complete or pyridoxine-deficient diet. Significant differences between dietary groups are found in ASAT activity in liver and percent stimulation of liver ASAT by the addition of pyridoxal-5′-phosphate after 8 wk. Clinical signs of vitamin B6 deficiency including anorexia, listlessness, frantic and erratic swimming, and ataxia were observed after 11 wk of feeding a pyridoxine-deficient diet. This study shows that vitamin B6 deficiency in rainbow trout can be readily determined weeks before signs of clinical deficiency are apparent by measuring pyridoxine-enhanced liver ASAT activity. However, liver levels of pyridoxine and pyridoxal are not sensitive indicators of vitamin B6 status.



PEDIATRICS ◽  
1966 ◽  
Vol 38 (6) ◽  
pp. 1068-1076
Author(s):  

Because of the limited information available it is not possible to derive precise figures for daily requirements of vitamin B6 in infants and children at this time. Data currently available suggest that the daily need in childhood is 0.5 to 1.5 mg and in adolescence is 1.5 to 2 mg. The requirement in infancy is clearly related to protein intake and is 20µg/gm of dietary protein. Requirements of a few individuals will undoubtedly be higher than the estimates for the normal population. Some of these patients will manifest frank biochemical and clinical signs of deficiency which will usually be promptly reversed by administration of small additional amounts of pyridoxine. Another group of patients will require large amounts of the vitamin to balance the heritable alteration in binding properties of a specific apoenzyme requiring pyridoxal phosphate for normal activity. It would appear that most infants, children and adults will have little difficulty in achieving an adequate intake of vitamin B6 if they receive what is considered to be in other respects an adequate diet.



2021 ◽  
pp. 247412642110287
Author(s):  
Diana Driscoll ◽  
David Callanan

Purpose: This work reports retinal findings in an adult patient with vitamin B6 deficiency. Methods: A case review of a single patient is presented. Results: A patient with a Roth-type retinal lesion and a history of nonepileptic seizures was found to have lymphocytic colitis. She was treated with pyridoxine, which resolved her seizures and the white-centered hemorrhage. Conclusions: Vitamin B6 deficiency should be considered in the differential diagnosis of patients presenting with white-centered hemorrhages and a history of nonepileptic seizures.



1994 ◽  
Vol 49 (9-10) ◽  
pp. 571-578 ◽  
Author(s):  
J. Sivý ◽  
V. Kettmann ◽  
J. Krätsmár-Šmogrovič

Abstract The crystal structure of [(N-salicylidene-ᴅ,ʟ-glutamato)(pyridine)]copper(II), a model for vitamin B6-amino acid-related metal complexes, has been determined by an X-ray analysis. A close examination of the structural data on this and other related complexes combined with quantum-chemical (INDO/2) calculations enabled us to make a clear distinction between two mechanisms proposed earlier for metabolic reactions of amino acids catalyzed by the vitamin B6 (or salicylaldehyde)-metal system. The results are consistent with a transient formation of a carbinolamine species resulting from the addition of a solvent water or alcohol molecule to the Schiff base double bond, thus supporting the mechanism of the catalysis as proposed by Gillard and Wootton.



2006 ◽  
Vol 9 (6) ◽  
pp. 779-784 ◽  
Author(s):  
A Waldmann ◽  
B Dörr ◽  
JW Koschizke ◽  
C Leitzmann ◽  
A Hahn

AbstractObjectiveThe study aimed to evaluate the dietary vitamin B6 intake and determine the vitamin B6 concentration in blood samples of German vegans.Design and settingCross-sectional study with 33 examination sites all over Germany.SubjectsNinety-three vegans (50 females) with a mean (±standard deviation (SD)) age of 43.7 ± 15.7 years who took no vitamin supplements.MethodsDietary intake was assed using a semi-quantitative food-frequency questionnaire. Erythrocyte aspartate aminotransferase activity coefficient (EAST-AC) was calculated as the ratio of stimulated (pyridoxal 5'-phosphate added) to unstimulated activity in blood samples that were provided after an overnight fast.ResultsMean ± SD vitamin B6 intake was 2.83 ± 0.98 mg day−1 and mean ± SD protein intake was 56.6 ± 21.7 g day−1. Of the participants 4% showed vitamin B6 intakes lower than daily recommended intakes for Germany, 16% showed EAST-AC > 1.85, and a further 58% showed EAST-AC of 1.5–1-85. Moderate vegans were affected to a lesser extent than strict vegans. None of the established confounders was a significant predictor of EAST-AC. In logistic regression analyses the contribution of nutriments and cereals to pyridoxine intake was the only predictor of EAST-AC classified as < 1.85 and ≥ 1.85, respectively.ConclusionsIn spite of the high total intake of vitamin B6, an adequate concentration in blood samples could not be realised for a majority of the participants. Due to the health implications of a marginal pyridoxine status, vegans should be encouraged to include foods with a high bioavailability of pyridoxine, such as beans, lentils and bananas, in the daily diet.



1955 ◽  
Vol 33 (1) ◽  
pp. 562-567
Author(s):  
John R. Beaton

Following earlier studies on carbohydrate metabolism in the vitamin-B6-deprived rat, in vitro investigations have been carried out. In all cases, comparisons were made between tissues from vitamin-B6-deprived and pair-fed control animals so that differences in the amount of food consumed would not affect the interpretation of experimental results. No significant difference was found in glucose utilization by muscle nor in liver cytochrome oxidase activity. Liver aldolase activity was significantly decreased and the activity of plasma alkaline phosphatase was significantly increased in the vitamin-B6-deprived rats. In vitamin-B6-deprived female rats, but not male rats, liver catalase activity was significantly increased. These results are discussed in the light of earlier observations indicating disturbances in carbohydrate metabolism in the vitamin-B6-deprived rat.



1971 ◽  
Vol 49 (9) ◽  
pp. 1026-1030 ◽  
Author(s):  
M. D. Avery ◽  
P. J. Lupien

The in vitro conjugation of labelled free cholic acid with glycine and taurine in the livers of vitamin B6-deficient and pair-fed rats has been investigated. It appears from these results that vitamin B6-deficiency stimulates this conjugation, and some evidence is given which suggests that vitamin B6 may be responsible for the lower capacity of conjugation observed in the liver of the pair-fed rat.



1959 ◽  
Vol 26 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Mary K. Davies ◽  
Margaret E. Gregory ◽  
Kathleen M. Henry

1. For chicks and rats pyridoxine, pyridoxal and pyridoxamine were equally active in terms of the free bases when given separately from the diet.2. Under our experimental conditions pyridoxine mixed with the chick diet was stable, but 20% of pyridoxamine, and a variable amount of pyridoxal was lost.3. The vitamin B6 activities measured with Saccharomyces carlsbergensis, chicks and rats respectively and expressed as μg. pyridoxine/g. freeze-dried milk were: raw milk 3·4, 3·2 and 4·9; evaporated milk 1·0, 2·1 and 2·7; stored evaporated milk 0·6, 1·4 and 2·0. For the chicks the milks were mixed with the diets; they were given separately to the rats.4. The microbiological and biological results for raw milk agreed within the limits of experimental error. For the processed milks the differences between biological and microbiological tests were statistically significant.5. All three methods of assay showed a 45–70% loss of vitamin B6 activity on processing and a further loss of 30% of the remainder after storage for 6 months at room temperature.We are indebted to Mr J. Rothwell, Department of Dairying, University of Reading, for preparing the evaporated milk and to Dr B. Record, Ministry of Supply, Microbiological Research Establishment, Porton, for freeze-drying the milk. We should like to thank Dr S. K. Kon for his interest in this work.



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