Jack M. Cooperman

Light (phototherapy)-induced riboflavin deficiency in the neonate

Phototherapy with blue light decomposes riboflavin, which has a maximum absorption at 450 nm. A study was designed to determine whether riboflavin deficiency developed in neonates who received phototherapy for moderate hyperbilirubinemia. Twenty-one infants with normal erythrocyte glucose-6-phosphate dehydrogenase activity were investigated. Five infants with moderate hyperbilirubinemia who did not require phototherapy served as the controls. Riboflavin deficiency was determined from the degree of saturation of erythrocyte glutathione reductase, a method shown to reflect riboflavin nutritional status in the neonate. Sixteen of 21 infants who were exposed to phototherapy developed riboflavin deficiency; all who had phototherapy for 49 hours or more developed the deficiency. That the concentration of serum bilirubin or the duration of hyperbilirubinemia was not a factor is supported by the fact that none of the controls became deficient. This observation may have important metabolic and clinical consequences for the neonate.

Folic acid metabolism in pregnancy.

Abstract There is increasing evidence that folic acid deficiency in pregnancy is more common than previously recognized and that this condition is associated with certain complications of pregnancy, both maternal and fetal. We have evaluated folate deficiency in pregnancy complications, normal pregnancies, and nonpregnant controls, employing the following procedures: (1) blood and marrow morphology, (2) urinary FIGLU excretion after histidine loading, and (3) fasting serum and whole blood L. casei folic acid activity. Results to date indicate that (1) significant folic acid deficiency may be present without overt megaloblastic anemia, (2) the incidence of deficiency in our population group is 22 per cent, (3) the incidence increases at or near term, and (4) the incidence is markedly increased in pregnancy complications, particularly toxemia. The possible maternal and infant hazards of abnormal folic acid metabolism are summarized, and the therapeutic implications presented.

Riboflavin metabolism in the hypothyroid human adult.

Abstract It had been shown that thyroxine regulates the conversion of riboflavin to riboflavin mononucleotide and flavin adenine dinucleotide (FAD) in laboratory animals. In the hypothyroid rat, the flavin adenine dinucleotide level of the liver decreases to levels observed in riboflavin deficiency. We have shown that in six hypothyroid human adults, the activity of erythrocyte glutathione reductase, an accessible FAD-containing enzyme, is decreased to levels observed during riboflavin deficiency. Thyroxine therapy resulted in normal levels of this enzyme while the subjects were on a controlled dietary regimen. This demonstrates that thyroid hormone regulates the enzymatic conversion of riboflavin to its active coenzyme forms in the human adult.

Erythrocyte Glutathione Reductase as a Measure of Riboflavin Nutritional Status of Pregnant Women and Newborns

Summary The assay of erythrocyte glutathione reductase (EGR) used to assess the riboflavin nutritional status has been modified to increase its utility. The levels of EGR in cord blood are significantly higher than those in the blood of well-nourished pregnant women at term. In both maternal and cord blood the activity coefficients (AC) were near 1, indicating that the EGR in both was saturated with FAD. This method to determine riboflavin deficiency can be applied to both pregnant women and newborns, and is not affected by increased reticulocytes.

Riboflavin deficiency in children with diabetes mellitus

SummaryTwenty-four insulin-dependent diabetic children and 114 normal control children, all between the ages of 6 to 16 years, were investigated for riboflavin deficiency. The method used was a measurement of erythrocyte glutathione reductase activity and the results were expressed as the activity coefficient (AC). None of the children had received vitamin supplementation. The percentage of diabetic children with riboflavin deficiency was 4 fold greater than in non diabetics. Supplementation with daily oral riboflavin quickly returned all AC values to normal.

Riboflavin deficiency in a pediatric population of low socioeconomic status in New York City.

1. Chantler C, Baum JD, and Norman DA: Dextrostix in the diagnosis of neonatal hypoglycemia, Lancet 2:1395, 1967. 2. Ente G, Klein SW, and Paraswanath BS: Evaluation of a direct-reading reflectometer for neonatal hypoglycemia screening, Am J Clin Pathol 61:612, 1974. 3. Levkoff AH, Duncan RC, Urquhart C, and Gershank JJ: Measuring neonatal blood glucose with a reflectance meter and test strips, Israel J Med Sci 7:598, 1971. 4. Schersten B, Kuhl C, Hollender A, and Ekman R: Blood glucose measurements with Dextrostix and new reflectance meter, Br Med J 3:384, 1974. 5. Snedecor GW, and Cochran WG: Statistical methods, ed 6, Ames, Iowa, 1972, Iowa State University Press, Chapters 6 and 7.

The Role of Histidine in the Anemia of Folate Deficiency

The amino acid histidine is metabolized to glutamic acid in mammalian tissue. Formiminoglutamic acid (FIGLU) is an intermediary in this reaction, and tetrahydrofolic acid is the coenzyme that converts it to glutamic acid. A test for folate deficiency concerns the measurement of urinary FIGLU excretion after a histidine load. It was observed that folate-deficient individuals receiving the histidine for the FIGLU test made hematological response that alleviated the anemia associated with this deficiency. This was unusual in that a biochemical test to determine the deficiency results in a beneficial effect for one aspect of the deficiency. The studies reported in this paper give a metabolic explanation for this phenomenon. Urine was collected for 24 hr from 25 folate-deficient subjects, 10 vitamin B12-deficient subjects, and 15 normal controls. Urinary excretion of histidine was a mean of 203 mg with a range of 130–360 mg for the folate-deficient subjects; 51.5 mg with a range of 30–76.6 mg for normal subjects; and 60.0 mg with a range of 32.3–93.0 mg for the vitamin B12-deficient subjects. All the folate-deficient subjects subsequently made a hematological response to the histidine administered for the FIGLU test. No hematological response was observed in the vitamin B12-deficient individuals. When folic acid was given to folate-deficient subjects who received no histidine, urinary histidine levels returned to normal levels rapidly and this was followed by a hematological response. Others have shown that volunteers fed a histidine-free diet developed anemia. In normal subjects, histidine is excreted much more in the urine than other essential amino acids are. Hemoglobin protein contains 10% histidine. Under normal conditions, dietary histidine can supply sufficient histidine to prevent anemia. When the dietary intake is diminished or the urinary excretion is greatly increased, anemia results. It is concluded that folate deficiency causes histidine depletion through increased urinary excretion of this amino acid. Feeding histidine replenishes tissue levels of histidine, resulting in hemoglobin regeneration. Folic acid administration results in return of histidine to normal urinary levels. Thus, a combination of folic acid histidine would be beneficial for folate deficient individuals.

An Improved Method to Assay Folates in Milk by a Turbidimetric Microbiological Assay

Abstract Folates in milk are heat labile and methods used to protect these folates during sample preparation for microbiological estimation of this vitamin result in opaque solutions unsuitable for turbidimetric assays. This has necessitated the use of titrimetric assay for milk folates which are long and cumbersome. By the use of rennin precipitation of casein under conditions which preserve the folate activity, an optically clear solution is obtained which can then be used for turbidimetric assay. This method is described in this paper.

Effect of erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency on light-induced riboflavin deficiency in the neonate.

Summary Five neonates with moderate hyperbilirubinemia and G-6-PD deficiency underwent phototherapy for periods of 48 to 120 hr. No biochemical evidence of ribo-flavin deficiency resulted. This contrasts with evidence of riboflavin deficiency observed in 15 of 16 infants with moderate hyperbilirubinemia but no G-6-PD deficiency who were exposed to light for periods of 48 hr or longer. The elevated FAD levels of the erythrocyte of the G-6-PD-deficient infants may have protected them from the light-induced vitamin deficiency.

VITAMIN B12 METABOLISM IN THALASSEMIA MAJOR

Megaloblastic anemia is now generally accepted as a not uncommon complication in patients with thalassemia major.’-4 This has usually been due to a deficiency of folic acid.’ Besides averting megaloblastic anemia, mild deficiencies of folic acid in thalassemia major in which the megaloblastic morphology may be masked by the thalassemia defect can result in a shorter interval between transfusions than would otherwise be the case.5 A deficiency of vitamin B12 in thalassemia patients may conceivably produce similar hematological disturbances. Reports of vitamin B12 deficiency in patients with the thalassemia syndrome, however, are rare. To our knowledge, the only previous studies in this area were those reported from India,”7 where 4 out of 27 patients having either thalassemia major or thalassemia-hemoglobin E disease had serum vitamin BIZ levels in the deficiency range. Thepurpose of this paper is to present the results of studies of vitamin Blz metabolism in thalassemia major with the principal aim of determining whether metabolic or physiological evidence of a vitamin B12 deficiency state can be demonstrated. Toward this end, three indices of vitamin BIZ metabolism were employed: ( I ) the serum vitamin BIZ level, ( 2 ) the urinary excretion of methylmalonate (MMA), and (3) the plasma disappearance of intravenously injected vitamin BIZ. Studies of vitamin B12 metabolism with the latter two indices in patients with thalassemia major have not been published previously. The second, a recently recognized index of vitamin Blz coenzyme f ~ n c t i o n , ~ ” is particularly useful in identifying vitamin B12 deficiency, especially if the latter is masked by a spuriously normal serum vitamin Blz level as may occur in liver A subsidiary purpose of this report is to present (1) a modification of the Lactobacillus lactis microbiological assay for vitamin B’2’’3 that provides a rapid and sensitive assay for the vitamin in serum, and ( 2 ) an improvement of the colorimetric assay of Giorgio and PlautI4 for the determination of urinary MMA, which increases the sensitivity of the original assay by reducing non-MMA-related colorproducing substances. Neither modification has been previously described in detail. 6