VITAMIN B2



Table of Contents
image Chemoprevention of oral leukoplakia and chronic esophagitis in an area of high incidence of oral and esophageal cancer.
image [Metabolism of riboflavin and B group vitamins functionally bound to it in insulin-dependent diabetes mellitus]
image Tissue concentrations of water-soluble vitamins in normal and diabetic rats.
image [Vitamin status in diabetic neuropathy (thiamine, riboflavin, pyridoxin, cobalamin and tocopherol)]
image Dietary methionine imbalance, endothelial cell dysfunction and atherosclerosis
image Relationship between liver cirrhosis death rate and nutritional factors in 38 countries
image [Comparison of metabolism of water-soluble vitamins in healthy children and in children with insulin-dependent diabetes mellitus depending upon the level of vitamins in the diet]
image [Criteria of supply of vitamins B1, B2, and B6 in children with insulin-dependent diabetes mellitus]
image [Metabolism of B group vitamins in patients with insulin-dependent and non-insulin dependent forms of diabetes mellitus]
image [Patients with type-II diabetes mellitus and neuropathy have nodeficiency of vitamins A, E, beta-carotene, B1, B2, B6, B12 and folic acid]
image Effects of oral contraceptives on nutritional status.
image Vitamin status in patients with inflammatory bowel disease
image Vitamins for seeing

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Chemoprevention of oral leukoplakia and chronic esophagitis in an area of high incidence of oral and esophageal cancer.

Ann Epidemiol. 1993 May. 3(3). P 225-34

This intervention trial carried out in Uzbekistan (former USSR) in an area with a high incidence of oral and esophageal cancer involved random allocation of 532 men, 50 to 69 years old, with oral leukoplakia and/or chronic esophagitis to one of four arms in a double-blind, two-by-two factorial design, with active arms defined by the administration of (a) riboflavin; (b) a combination of retinol, beta-carotene, and vitamin E; or (c) both. Weekly doses were 100,000 IU of retinol, 80 mg of vitamin E, and 80 mg of riboflavin. The dose of beta-carotene was 40 mg/d. Men in the trial were followed for 20 months after randomization. The aim of the trial was to determine whether treatment with these vitamins or their combination could affect the prevalence of oral leukoplakia and/or protect against progression of oral leukoplakia and esophagitis, conditions considered to be precursors of cancer of the mouth and esophagus. A significant decrease in the prevalence odds ratio (OR) of oral leukoplakia was observed after 6 months of treatment in men receiving retinol, beta-carotene, and vitamin E (OR = 0.62; 95% confidence interval (CI): 0.39 to 0.98). After 20 months of treatment, no effect of vitamin supplementation was seen when the changes in chronic esophagitis were compared in the four different treatment groups, although the risk of progression of chronic esophagitis was lower in the subjects allocated to receive retinol, beta-carotene and vitamin E (OR = 0.65; 95% CI: 0.29 to 1.48) A secondary analysis not based on the randomized design revealed a decrease in the prevalence of oral leukoplakia in men with medium (OR = 0.45; 95% CI: 0.21 to 0.96) and high (OR = 0.59; 95% CI: 0.29 to 1.20) blood concentrations of beta-carotene after 20 months of treatment. Risk of progression of chronic esophagitis was also lower in men with a high blood concentration of beta-carotene, odds ratios being 0.30 (95% CI: 0.10 to 0.89) and 0.49 (95% CI: 0.15 to 1.58) for medium and high levels, respectively. A decrease in risk, also statistically not significant, was observed for high vitamin E levels (OR = 0.39; 95% CI: 0.14 to 1.10). These results were based on levels of vitamins in blood drawn after 20 months of treatment.



[Metabolism of riboflavin and B group vitamins functionally bound to it in insulin-dependent diabetes mellitus]

Vopr Med Khim (RUSSIA) Sep-Oct 1993, 39 (5) p33-6

In 35 children of 9-13 years old with insulin-dependent diabetes mellitus distinct alterations in metabolism of vitamin B2 were detected, which were manifested as elevated rate of riboflavin excretion with urine and a decrease in the vitamin content in erythrocytes, as 1.5-fold increase in activity of erythrocyte glutathione reductase and augmented affinity of erythrocyte glutathione reductase to exogenous FAD. Alterations in metabolism of riboflavin did not involve the vitamin deficiency as shown by analysis of vitamins B6 and PP (4-pyridoxic acid and I-methyl nicotinamide, respectively) excretion with urine as well as by study of the coenzymes content in blood of healthy and sick children with various rates of riboflavin consumption. Rates of 4-pyridoxic acid and I-methyl nicotinamide excretion with urine were similar both in healthy children of 9-13 years and in children of this age with diabetes mellitus. The data obtained suggest that rates of riboflavin consumption in patients with diabetes mellitus differed from those of healthy persons; these reasons should be taken into consideration in evaluation of vitamins B2 consumption in patients with diabetes mellitus.



Tissue concentrations of water-soluble vitamins in normal and diabetic rats.

Int J Vitam Nutr Res (SWITZERLAND) 1993, 63 (2) p140-4

Changes in circulating and tissue concentrations of several vitamins have been reported in diabetic animals and human subjects. In this study, the effect of short-term (2 weeks) streptozotocin diabetes on folate, B6, B12, thiamin, nicotinate, pantothenate, riboflavin and biotin in liver, kidney, pancreas, heart, brain and skeletal muscle of rats was investigated. The tissue distribution of vitamins varied widely in normal rats. Diabetes significantly lowered folate in kidney, heart, brain, and muscle; B6 in brain; B12 in heart; thiamin in liver and heart; nicotinate in liver, kidney, heart and brain; pantothenate in all tissues; riboflavin in liver, kidney, heart, and muscle. These results indicate that experimental diabetes causes a depression of several water-soluble vitamins in various tissues of rats.



[Vitamin status in diabetic neuropathy (thiamine, riboflavin, pyridoxin, cobalamin and tocopherol)]

Z Ernahrungswiss (GERMANY, WEST) Mar 1980, 19 (1) p1-13

Investigations on the vitamin pattern of diabetic neuropathy: thiamine, riboflavin, pyridoxine, cobalamin and tocopherol. The contents of the vitamins mentioned above have been measured in the blood of 119 patients (53 diabetic neuropathies, 66 diabetics without neuropathy). The incidence of neuropathy shows a strong correlation with the duration of the diabetic state, but not with sex, nor with concomitant diseases such as adipositas, hypertension, heart and circulatory diseases, except retinopathia diabetica. Most of the diabetics in our study are well supplied with vitamins B1, B2, and E; B6 and B12 are occasionally low, but there is no statistically relevant difference between diabetic controls and neuropathies. Adipose patients have neither a markedly different vitamin content nor a different calory uptake from non-adipose patients. A general trend towards reduced total calory uptake is seen in old age, men (lower protein intake) and women (lower carbohydrate intake) obviously differing somewhat in their habits. The influence of therapy on the vitamin pattern is not clear cut, except for patients under diet and biguanide-therapy showing a higher proportion of low or subnormal B12 values. The increased frequency of neuropathies in patients treated with sulfonyl-urea approaches only the limits of significance and needs further investigations.



Dietary methionine imbalance, endothelial cell dysfunction and atherosclerosis

Nutrition Research (USA), 1996, 16/7 (1251-1266)

Dietary factors can play a crucial role in the development of atherosclerosis. High fat, high calorie diets are well known risk factors for this disease. In addition, there is strong evidence that dietary animal proteins also can contribute to the development of atherosclerosis. Atherogenic effects of animal proteins are related, at least in part, to high levels of methionine in these proteins. An excess of dietary methionine may induce atherosclerosis by increasing plasma lipid levels and/or by contributing to endothelial cell injury or dysfunction. In addition, methionine imbalance elevates plasma/tissue homocysteine which may induce oxidative stress and injury to endothelial cells. Methionine and homocysteine metabolism is regulated by the cellular content of vitamins B6, B12, riboflavin and folic acid. Therefore, deficiencies of these vitamins may significantly influence methionine and homocysteine levels and their effects on the development of atherosclerosis.



Relationship between liver cirrhosis death rate and nutritional factors in 38 countries

INT. J. EPIDEMIOL. (United Kingdom), 1988, 17/2 (414-418)

The relationship between liver cirrhosis death rates and certain nutritional factors was studied in 38 countries where mortality statistics were considered to be reliable. A partial correlation analysis showed that several food commodity consumption factors were independently and negatively (p < 0.01) associated with liver cirrhosis death rates after adjustment for alcohol consumption. These factors were total calories, protein, fat, calcium, vitamin A and vitamin B2. The significant association of protein, vitamin A, vitamin B2 and calcium with the cirrhosis death rates is of importance since they were not intercorrelated with alcohol consumption. Further results showed that animal protein was more significantly related to cirrhosis death rates than vegetable protein. However, in view of certain limitations of this study, the findings do not necessarily reflect causal relationships but rather support the consideration by scientists that protein and vitamin deficiency may have certain effects on liver cirrhosis.



[Comparison of metabolism of water-soluble vitamins in healthy children and in children with insulin-dependent diabetes mellitus depending upon the level of vitamins in the diet]

Vopr Med Khim (RUSSIA) Apr-Jun 1996, 42 (2) p153-8

Metabolism of vitamins C, B2, B6 and niacin in children with insulin-dependent diabetes mellitus was distinctly different from that of healthy persons of the same age as shown by studies of the correlation between content of vitamins or their coenzyme forms in blood, excretion of the vitamins with urine and content of the vitamins in a diet. These data corroborated once again that in estimation of the vitamins consumption suitable for ill children, the criteria of healthy children requirements for vitamins should not be taken into consideration. Dissimilar metabolism in healthy and impaired persons may also demonstrate some differences in consumption of these vitamins. Preliminary data showed that requirements of the impaired children for vitamin C were slightly increased, for vitamin B2--similar or slightly decreased as compared with healthy children. These results suggest that additional investigations are required for evaluation of vitamins consumption in children with diabetes mellitus of the I type.



[Criteria of supply of vitamins B1, B2, and B6 in children with insulin-dependent diabetes mellitus]

Vopr Med Khim (RUSSIA) Nov-Dec 1995, 41 (6) p58-62

By mathematically analysing the curves of urinary excretion of vitamins, their plasma and erythrocytic concentrations or of TDP-effect, by constructing and mathematically interpreting the variation curves of distribution of a given plasma concentration of riboflavin and pyridoxal phosphate for 10-14-old-year children suffering from insulin-dependent diabetes mellitus after supplementation of vitamin, as a criterion of normal requirement for vitamin B2, the authors are prone to recommend the concentration of riboflavin over 10 micrograms/ml in plasma and over 96 micrograms/ml in erythrocytes, the hourly excretion of more than 27 micrograms. It has been ascertained that the criteria for the optimal body's requirements for vitamins in diabetes mellitus children do not differ from those in healthy age-matched children. Thus, the value of TDP-effect is less than 1.25, the concentration of pyridoxal phosphate is over 8.4 micrograms/ml plasma, the excretion values of thiamine and 4-pyridoxic acid are 13.5 and 64.0 micrograms/h, respectively.



[Metabolism of B group vitamins in patients with insulin-dependent and non-insulin dependent forms of diabetes mellitus]

Vopr Med Khim (RUSSIA) Sep-Oct 1993, 39 (5) p26-9

Metabolism of vitamins B, involving evaluation of these vitamins content in blood and excretion of their metabolites with urine, was studied in adult healthy persons as well as in patients with insulin-dependent and -independent forms of diabetes mellitus. Distinct alterations in metabolism of vitamin B2 were detected in the insulin-dependent diabetes: its content in erythrocytes and the rate of excretion with urine were increased. This phenomenon made some problems in evaluation of riboflavin consumption in patients with diabetes mellitus of the I type, while parameters of vitamin consumption in insulin-independent diabetes were similar to those of healthy persons. Parameters of metabolism of vitamins B1, B6 and PP were not different in patients with insulin-dependent and -independent forms of diabetes mellitus. Rates of excretion of 4-pyridoxic acid, 1-methyl nicotinamide, thiamine with urine as well as concentration of the corresponding vitamins in blood were similar to those parameters of healthy persons.



[Patients with type-II diabetes mellitus and neuropathy have nodeficiency of vitamins A, E, beta-carotene, B1, B2, B6, B12 and folic acid]

Med Klin (GERMANY) Aug 15 1993, 88 (8) p453-7

The present study was aimed to determine the vitamin status of vitamins A, E, beta-carotene, B1, B2, B6, B12 and folate in plasma using HPLC and vitamins B1, B2 and B6 in erythrocytes using the apoenzyme stimulation test with the Cobas-Bio analyzer in 29 elderly type II diabetic women with (G1: n = 17, age: 68.6 +/- 3.2 years) and without (G2: n = 12, age: 71.8 +/- 2.7 years) diabetic polyneuropathy. The basic parameters as age, hemoglobin A1c, fructosamine and duration of the disease did not differ in both groups. Furthermore, retinopathy was assessed with fundoscopy and nephropathy with creatinine clearance. The creatinine clearance (G1: 50.6 +/- 3.4 vs. G2: 63.6 +/- 3.7 ml/min, 2p < 0.025) and the percentage of retinopathy (G1: 76.5% vs. G2: 16.7%, 2p = 0.002) were different indicating that G1 had significantly more severe late complications than G2. Current plasma levels of all measured vitamins (A, E, beta-carotene, B1, B2, B6, B12 and folate) and the status of B1, B2 and B6 in erythrocytes did not vary between the two groups (2p > 0.1). In summary, we found a lack of association between the actual vitamin condition in plasma and erythrocytes and diabetic neuropathy.



Effects of oral contraceptives on nutritional status.

Am Fam Physician (UNITED STATES) Jan 1979, 19 (1) p119-23

Major effects of oral contraceptives on nutritional status are elevation of triglycerides, decline in glucose tolerance, an apparent increase in the need for folate and vitamins C, B2 and B6, and a decrease in iron loss. Women at greater risk of nutritional deficits due to oral contraceptives include those who have just had a baby, are planning to have a baby later, already show nutritional deficiencies, have had recent illness or surgery, have poor dietary habits, are still growing or have a family history of diabetes or heart disease.



Vitamin status in patients with inflammatory bowel disease

Fernandez-Banares F.; Abad-Lacruz A.; Xiol X.; Gine J.J.; Dolz C.; Cabre E.; Esteve M.; Gonzalez-Huix F.; Gassull M.A.

Department of Gastroenterology, Hospital de Bellvitge 'Princeps d'Espanya', Barcelona Spain

AM. J. GASTROENTEROL. (USA), 1989, 84/7 (744-748)

The status of water- and fat-soluble vitamins was prospectively evaluated in 23 patients (13 men, 10 women, mean age 33 plus or minus 3 yr) admitted to the hospital with acute or subacute attacks of inflammatory bowel disease. Protein-energy status was also assessed by means of simultaneous measurement of triceps skin-fold thickness, mid-arm muscle circumference, and serum albumin. Fifteen patients (group A) had extensive acute colitis (ulcerative or Crohn's colitis), and eight cases (group B) had small bowel or ileocecal Crohn's disease. Eighty-nine healthy subjects (36 men, 53 women, mean age 34 plus or minus 2 yr) acted as controls. In both groups of patients, the levels of biotin, folate, beta-carotene, and vitamins A, C, and B1 were significantly lower than in controls (p < 0.05). Plasma levels of vitamin B12 were decreased only in group B (p < 0.01), whereas riboflavin was lower in group A (p < 0.01). The percentage of patients at risk of developing hypovitaminosis was 40% or higher for vitamin A, beta-carotene, folate, biotin, vitamin C, and thiamin in both groups of patients. Although some subjects had extremely low vitamin values, in no case were clinical symptoms of vitamin deficiency observed. Only a weak correlation was found between protein-energy nutritional parameters and vitamin values, probably due to the small size of the sample studied. The pathophysiological and clinical implications of the suboptimal vitamin status observed in acute inflammatory bowel disease are unknown. Further studies on long-term vitamin status and clinical outcome in these patients are necessary.



Vitamins for seeing

COMPR. THER. (USA), 1990, 16/4 (62)

It has long been known that an inadequate diet lacking in certain essential vitamins can cause ocular disorders. On an Egyptian papyrus dated about 1500 BC, it is recorded that liver was used as a food to cure night blindness. Healthy eyes depend on a well-balanced diet. Vitamin A maintains the normal function of the epithelial cells of the eye and is essential for the synthesis of visual photosensitive pigments. Deficiencies of vitamin A lead to clinical manifestations including night blindness, conjunctival pigmentation, and dry eyes. The B vitamins are important for maintaining good vision. Vitamin B1 (thiamine) deficiency produces optic nerve dysfunction. Vitamin B12 deficiency can produce vascular changes in the retina. Deficiency of riboflavin (part of the B complex) has been implicated in the formation of cataracts and may also be a factor in producting xerophthalmia (dry eyes). Vitamin C is necessary to prevent scurvy. The scorbutic manifestations in the eyes are bleeding from the lids, conjunctiva, anterior chamber, and retina. Vitamin C deficiency may also be a factor in cataract formation. Finally, vitamin K deficiency causes retinal hemorrhages in neonates. Deficiencies of vitamin D and E have not been shown to have a negative effect on the visual process, but vitamin E therapy improves retrolental fibroplasia (retinopathy of prematurity).

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