Riboflavin and riboflavin-derived cofactors in adolescent girls with anorexia nervosa

BACKGROUND

Thyroid hormones, riboflavin, riboflavin cofactors, and organic acids were assessed in girls with anorexia nervosa.

OBJECTIVE

The objective was to examine the effect of malnutrition and low thyroid hormone concentrations on erythrocyte and plasma riboflavin metabolism and their relation with urinary organic acid excretion.

DESIGN

Seventeen adolescent girls with anorexia nervosa [body mass index (BMI; in kg/m2): 14.8 +/- 2.2] and 17 age-matched, healthy girls (control subjects; BMI: 20.5 +/- 2.2) took part in the feeding study. Erythrocyte and plasma riboflavin as well as riboflavin cofactors (flavin mononucleotide and flavin adenine dinucleotide) were assessed by HPLC, whereas urinary organic acids were assessed by gas chromatography-mass spectrometry.

RESULTS

Anorectic patients who began a feeding program had higher erythrocyte riboflavin (3.5 +/- 2.2 compared with <0.1 nmol/mol hemoglobin; P < 0.001), lower plasma flavin adenine dinucleotide (57.8 +/- 18.5 compared with 78.5 +/- 54.3 nmol/L; P < 0.05), and higher urinary ethylmalonic acid (7.12 +/- 4.39 compared with 1.3 +/- 2.8 micromol/mmol creatinine; P < 0.001) and isovalerylglycine (7.65 +/- 4.78 compared with 3.8 +/- 0.9 micromol/mmol creatinine; P < 0.05) concentrations than did control subjects. Triiodothyronine concentrations were low and negatively correlated with plasma riboflavin concentrations (r = -0.69, P < 0.01). Not all patients showed improvements in these biochemical indexes after 30 d of refeeding.

CONCLUSIONS

The low triiodothyronine concentrations observed in anorexia nervosa could alter the extent of riboflavin conversion into cofactors, thus leading to high erythrocyte riboflavin concentrations, low plasma flavin adenine dinucleotide concentrations, and high rates of ethylmalonic acid and isovalerylglycine excretion.

Breakfast type, daily nutrient intakes and vitamin and mineral status of French children, adolescents, and adults

OBJECTIVE

To examine associations between the consumption of different types of breakfasts, dietary intakes, and selected indices of nutritional status.

METHODS

Dietary intakes were obtained using the dietary history method, and serum bioassays were used to assess vitamin and mineral status in a representative community-based sample of 1108 French children (ages 2 to 10 years), adolescents (ages 10 to 18 years), and adults (ages 18 to 65 years). Breakfasts were divided into three categories: low-energy (<15% of the energy RDA), medium-energy (15-25%) and high-energy (>25%).

RESULTS

High-energy breakfasts were associated with the consumption of ready-to-eat (RTE) cereals. High-energy breakfasts and cereal consumption, both more common among children and adolescents than among adults, were also associated with a greater proportion of daily energy from carbohydrate and lower proportion of energy from fat. High-energy breakfasts and cereal consumption were further associated with higher intakes of vitamins and minerals as measured by percent RDAs. High-energy breakfasts and cereal consumption were associated with lower serum cholesterols and improved biochemical indices of nutritional status. Serum concentrations of vitamin B1 (in children and adolescents), vitamin B2 and beta-carotene (in adults) were significantly linked to the level of energy provided by breakfast.

CONCLUSION

The consumption of breakfast cereals appears to have a positive impact on nutritional status regardless of age.

[Metabolism of vitamins B1 and B2 during phenylketonuria]

Vitamin level in blood plasma and erythrocytes and a rate of urinary excretion of vitamin metabolites were analysed in children suffering from phenylketonuria. It has been shown that vitamin B1 metabolism and therefore the criteria of the adequate sufficiency with this vitamin does not differ from those for healthy people. Increased riboflavin urinary excretion under its decreased plasma and erythrocyte levels has been demonstrated for PKU children. In consequence of this the indexes of sufficiency significantly differ from those of the healthy adequately supplied with this vitamin children and are equal to 4 ng of riboflavin per 1 ml of blood plasma and its urinary excretion more than 50 mg/h. The necessity for the redetermination of vitamin B2 diet optimal content under this disease and its biochemical validation are discussed.

Enzymic evaluation of thiamin, riboflavin and pyridoxine status of parturient mothers and their newborn infants in a Mediterranean area of Spain

OBJECTIVE

To determine the biochemical status of thiamin, riboflavin and pyridoxine in parturient mothers and their newborn infants in a Mediterranean region.

DESIGN

Transveral study.

SETTING

St Joan University Hospital and Faculty of Medicine & Health Sciences, Universitat Rovira i Virgili, Reus, Spain.

SUBJECTS

131 healthy parturient mothers, with normal pregnancies and deliveries in St Joan University Hospital, and their newborn infants.

INTERVENTIONS

Erythrocyte haemolysates were prepared from maternal blood at delivery and infants' umbilical cord blood and used to measure micronutrient status using the transketolase, glutathione reductase and aspartate aminotransferase coenzyme stimulation tests.

RESULTS

Maternal and infant coenzyme activities were significantly correlated, but infant coenzyme status was better than maternal, with significantly higher basal and stimulated activity (P < 0.001) and significantly lower activation coefficients (P < 0.001). Inadequate thiamin, riboflavin or pyridoxine status occured in 38.2 62.6% (50-82) of the mothers and 3.1-37.4% (4 49) of the infants; 85.2% (46/54), 12.9% (4/31) and 24.1% (12/54) of infants born to mothers with biochemical deficiency of either thiamin, riboflavin or pyridoxine, respectively also had inadequate status. Maternal deficiencies in more than one vitamin further increased the risk of infant thiamin and pyridoxine deficiency. Maternal and infant riboflavin status were significantly correlated with fetal development (e.g. length at birth, P < 0.001). The incidence of thiamin deficiency in paturient mothers in Spain was the highest out of a 12-country comparison.

CONCLUSIONS

Inadequate status for each vitamin was evident in mothers and infants. Maternal status of each individual vitamin, but especially riboflavin, was affected by maternal status of the other vitamins. Infant thiamin status was the most adversely affected by maternal deficiencies in more than one vitamin. Infant riboflavin status, however, was apparently protected from adverse maternal status.

Folic acid, riboflavin, thiamine, and vitamin B-6 status of a group of first-time blood donors

Reference intervals for long-term status measures of folate, riboflavin, thiamine, and vitamin B-6 were determined in a select group of adults. Reference subjects had no adverse medical history and did not use tobacco, alcohol, or nutritional supplements, and their diets met > or =70% of the Australian recommended dietary intake for nutrients. Red blood cell concentrations of thiamine and folate were measured by microbiological methods. Vitamin B-6 and riboflavin status were measured on the basis of the erythrocyte aspartate transaminase activity coefficient and erythrocyte glutathione reductase activity coefficient, respectively. A survey of first-time blood donors, which was conducted in Australia in 1995, revealed a significant prevalence of low red blood cell thiamine concentrations (13%) when compared with the calculated normal reference intervals. However, the most important finding in the survey was that the group of healthy, nonanemic adults (first-time blood donors) was found to have a median red blood cell folate concentration 24% below the median concentration of the carefully selected (nonsupplemented) reference group. Plasma total homocysteine concentrations indicated folate deficiency in the reference group. Therefore, the 2.5th percentile cutoff for reference group red blood cell folate concentrations may have underestimated the prevalence of folate deficiency in the survey group. These data, coupled with the lack of Australian food-composition data for folate in particular, reinforce the need for monitoring nutritional status by both dietary and biochemical means. We recommend consideration of mandatory fortification of the Australian food supply with folic acid.

The study of riboflavin requirement in broiler chickens

Riboflavin status indices in tissues (brain, liver, heart) and blood plasma, and performance parameters were studied in male and female broiler chickens in response to a wide range of dietary supplementation of riboflavin in order to establish the requirement for riboflavin in fast growing modern broilers. The birds fed riboflavin supplemented diets were increasing their body weight at a higher rate than those fed the unsupplemented diet, but this was apparent only during the first stage of growth (days 1 to 21). Supplementation of 2 mg riboflavin per kg was sufficient to support the maximum growth rate. Feed consumption was not affected by different levels of dietary supplementation of riboflavin. The supplementation of riboflavin in the diet increased (p < 0.001) plasma riboflavin level, but the magnitude of response decreased with age. The main component in the tissues was FAD, followed by FMN and riboflavin. Overall, the dietary riboflavin supplementation had highly significant (p < 0.001) effects on tissue FAD, FMN, and riboflavin status, but the effect of supplementation was clearly pronounced only at days 7 and 14, and thereafter the status of FAD, FMN, and riboflavin in the tissues did not differ between unsupplemented and supplemented birds. Neither FAD, FMN, and riboflavin nor GSSG-RED activity correlate with the level of supplementation. Saturation levels of riboflavin in the blood plasma and tissues, corresponded with dietary riboflavin levels of supplementation at 1 to 2 mg per kg. Based on the performance and biochemical data, the dietary requirement of riboflavin for fast growing broilers should be set at a level of 5 mg/kg. The currently recommended allowance of 3.6 mg riboflavin per kg of ration is not sufficient for modern breeds of broiler chickens.

Molybdenum, xanthine oxidase and riboflavin levels in tamoxifen treated postmenopausal women with breast cancer

40 cases postmenopausal women with breast cancer constituted the study group and 20 sex and age matched formed the control group. The study group of untreated patients showed nonsignificant decrease in molybdenum but significant decrease in blood xanthine oxidase and riboflavin levels. Tamoxifen treated patients showed nonsignificant increase in molybdenum, after 3 months, significant increase after 6 months and significant increase in xanthine oxidase and riboflavin levels. Thus tamoxifen when given in breast cancer helps in amelioration of the diseased condition.

Effect of magnesium deficiency on vitamin B2 and B6 status in the rat

OBJECTIVE

The present study was undertaken to investigate the effect of dietary magnesium (Mg) deficiency on vitamin B2 (riboflavin) and B6 (pyridoxine) status in rats.

METHODS

We fed Wistar rats an Mg-deficient diet (56 mg magnesium per kg food) for 70 days. On days 21, 35 and 70 we measured Mg and manganese (Mn) in plasma and whole blood, alkaline phosphatase in plasma, erythrocyte glutathione reductase activity coefficient (AC-EGR) for riboflavin status, and erythrocyte aspartase transaminase activity coefficient (AC-EAST) for vitamin B6 status.

RESULTS

Intake of the Mg-deficient diet significantly decreased plasma and whole blood levels of Mg and plasma alkaline phosphatase activity on all sampling days. The Mg deficit had no effect on plasma concentrations of Mn, but significantly increased whole blood levels of this element on days 35 and 70. The Mg-deficient diet had no effect on AC-EGR, and thus appeared not to affect riboflavin status. However, AC-EAST was significantly increased on day 70, implying that the animals were at risk for vitamin B6 deficiency.

CONCLUSION

Mg deficiency impairs vitamin B6 status by depleting intracellular Mg and thus inhibits the activity of alkaline phosphatase, a metalloenzyme required for the uptake of pyridoxal phosphate by tissues. Although part of the intraerythrocyte loss of Mg is countervailed by Mn, which can act as a substitute activator of alkaline phosphatase, the degree of compensation is insufficient to fully offset the decrease in activity caused by Mg depletion.

[Influence of lead on metabolism of vitamins B group in alimentary iron deficient rats]

Experimentally induced lead poisoning especially under simultaneous iron deficit leads to the development of secondary thiamine insufficiency. Erythrocyte riboflavin content and erythrocyte glutathion reductase and aspartate aminotransferase activities have been demonstrated to be increased. Lead treatment is accompanied with the increase of urinary excretion of riboflavin, 4-pyridoxic acid and 1-vtthylnicotinamide in rats fed with adequate diet. Thus lead intoxication and iron deficiency influence vitamin B group metabolism.

[Vitamin provision in children of some Ukraine regions]

The investigation dealt with testing vitamins A,E,B1 and B2 levels in the blood of children residing in different regions of Ukraine. The existence of polyhypovitaminosis, especially in children suffering from gastrointestinal tract disease was displayed. 28% of the children may be attributed to a risk group. Some measures directed to polyhypovitaminosis elimination in children, residing in Ukraine, are proposed.

Relationships between micronutrient intake and biochemical indicators of nutrient adequacy in a "free-living' elderly UK population

Nutritional assessments are frequently based on amounts of nutrients consumed. In the present paper the usefulness of nutrient intake data for assessing nutrient adequacy is examined in an elderly British population. Subjects were "free-living' elderly aged 68-90 years (sixty men, eighty-five women) in Norwich. Forty-two of forty-nine surviving males and sixty-seven of seventy-nine surviving females were reassessed after 2 years. With few exceptions, estimated micronutrient intake was not statistically predictive of biochemical measures of nutrient adequacy. Initial biochemical measures of nutritional adequacy were compared with those found 2 years later in an attempt to assess whether initial biochemical assessment was predictive of the "longer term' situation. Biochemical measurements at the start of the study were correlated to the same measurements made 2 years later for: serum ferritin, haemoglobin and erythrocyte count, whole-blood Se-glutathione peroxidase (EC 1.11.1.9; males only), plasma Cu, alkaline phosphatase (EC 3.1.3.1), ascorbic acid, vitamin B6 (pyridoxal-5-phosphate), folate and vitamin B12, total erythrocyte thiamin (males only), riboflavin (erythrocyte glutathione reductase (EC 1.6.4.1) activation coefficient): but not for: erythrocyte Cu-superoxide dismutase (EC 1.15.1.1) or plasma Zn. Either only small changes, or no changes, in mean values were seen over the 2 years for most of the biochemical measures. One exception was a large increase in plasma folate. The only important "negative' features seen at 2-year follow up were a large fall in serum ferritin concentration and a large increase in the activity of two antioxidant defence enzymes, superoxide dismutase and glutathione peroxidase. As judged by currently accepted biochemical deficiency threshold values, a small proportion of subjects were possibly at risk of Fe (3% men; 1% women), folate (7%, 3%), thiamin (12%; 3%) and vitamin C (15%; 17%) deficiency. Many more appeared to be at risk of vitamin B6 (42%; 47%) and riboflavin (77%; 79%) deficiency. It was concluded that the requirements of the elderly for vitamins B1, B2 and C, and the biochemical deficiency threshold values used to indicate vitamin B6 deficiency, need review.

[Study of the relationship between indicators of provision with vitamins B2 and B6 of children 7-10 years of age with mental retardation]

Study of the vitamin status of 34 children of both sexes aged 7 to 10, pupils of a school for children with mental retardation in the city of Krasnoyarsk revealed that the values of riboflavin and 4-pyridoxic acid excretion per g of creatinine, which are in good correlation with the content of the respective vitamins in the blood, reflect the saturation with these nutrients and may be used for assessing vitamin supply. Excretion of at least 200 mg of riboflavin per g of creatinine corresponds to normal provision of a child with this vitamin.

The vitamin status of young British adults

Using biochemical indices thiamin, riboflavin, pyridoxine, ascorbic acid, retinol, alpha-tocopherol, folic acid, cyanocobalanin, carotene and biotin status were assessed in a sample of 243 young British adults. Using conventional definitions the number of individuals whose vitamin status can be described as adequate, marginal or deficient was determined. Vitamin status was related to alcohol intake and smoking. The status of ascorbic acid, cyanocobalamin, alpha-tocopherol, folic acid and in males retinol, was adequate in the majority of cases. In the cases of riboflavin and pyridoxine the status of a substantial minority was either borderline or deficient. The thiamin and biotin status of a minority of both sexes, and retinol in the females, was marginal. In males alcohol was associated with better retinol, ascorbic acid, alpha-tocopherol and pyridoxine status and lower levels of biotin. Lower carotene values were associated with drinking alcohol. In both sexes those who smoked had lower ascorbic acid, folic acid and carotene values. In males smoking was additionally associated with lower riboflavin and biotin; in females cyanocobalamin and alpha-tocopherol were lower. As all the subjects were students volunteers, care should be taken in generalizing the data to other groups.

The effects of triethanolamine myristate, a fatty acid salt, on the bioavailability of riboflavin in dogs

A study in dogs was performed in which a physiologic approach to delaying gastric emptying was examined. Triethanolamine myristate (a fatty acid salt) was used to delay gastric emptying in hopes of increasing the bioavailability of riboflavin. A bilayer tablet consisting of triethanolamine myristate and riboflavin resulted in an absolute bioavailability of 2-3 times greater than the bioavailability of riboflavin alone. Increases in bioavailability although to a lesser extent, were also seen with the 30 min pretreatment with triethanolamine myristate. The results suggest that it was possible to delay gastric emptying.

Estimation of vitamin needs--riboflavin, vitamin B6 and ascorbic acid-according to blood parameters and functional-cognitive and emotional indices in a selected well-established group of elderly in a home for the aged in Israel

OBJECTIVE

To evaluate the vitamin status and the effects of micronutrient supplementation as determined by biochemical assays and functional, cognitive and emotional tests in a selected well-established group of elderly people, average age above 80 years.

METHODS

Dietary consumption was evaluated by in-person interview using a food frequency questionnaire. Medical, biochemical, nutritional, functional, cognitive and behavioral parameters were assessed in elderly subjects (n = 12) living in a home for the aged, at baseline and after 42 days of micronutrient supplementation. The same parameters were assessed in additional subjects (n = 9), at baseline only.

RESULTS

In all subjects, most of the micronutrients were not supplied at an adequate level. Supplementation of micronutrients at a level of 100% RDA improved parameters related to vitamin status, the activation coefficients (AC) of GR (glutathione reductase) and AST, blood ascorbic acid concentrations, functional-cognitive evaluation values, blood pressure, pulse rate, and serum cholesterol and triglycerides levels. At baseline, the following parameters significantly correlated with vitamin intake and were used for the estimation of vitamin needs: AC of GR, Tinetti Balance Evaluation, FIM and recorded morbidity.

CONCLUSIONS

On the basis of limited available data, calculation of vitamin needs based on regression lines resulted in estimates (mg/day) of: > 150 for ascorbic acid, > 3 for riboflavin, > 3 for vitamin B6. Expanding the current practice of supplementing micronutrients at a level of 100% RDA (in tablet form) that already exists in some elderly societies should be considered after a comprehensive study in a large group of elderly people.

Plasma and urine riboflavin and pyridoxine concentrations in enterally fed very-low-birth-weight neonates

Preterm infant formulas (PIFs) for very-low-birth-weight (VLBW) infants (birth weight, < 1,500 g) are augmented to provide daily riboflavin and pyridoxine at levels up to five-fold greater than in term infant formula and 18-fold greater than in human milk. We evaluated plasma riboflavin and pyridoxine concentrations in VLBW infants who received PIF during their first postnatal month. Eighty-eight plasma and 124 urine samples were collected for riboflavin- and pyridoxine-concentration measurements from 57 clinically healthy VLBW infants weekly during their first postnatal month. Concentrations were measured using high-performance liquid chromatography. At the time of the sample, patients were receiving > or = 80% of their total calories via enteral feedings. Plasma riboflavin concentrations rose from 45.3 +/- 7.3 ng/ml at baseline (mean +/- SEM) to 173.5 +/- 20.3 ng/ml by 1 week of age and remained at 177.3-199.7 ng/ml during the following three weekly measurements; values were up to 14-fold above baseline concentration. Urine riboflavin concentration increased from 534 +/- 137 ng/ml at baseline to 3,521 +/- 423 ng/ml by 1 week of age and remained at 4,451-5,216 ng/ml during the next 3 weeks. In a similar pattern, baseline plasma (69.4 +/- 10.4 ng/ml) and urine (145 +/- 30 ng/ml) pyridoxine concentrations were significantly increased by 1 week postnatal age; they remained at 163-248 ng/ml (plasma) and 1,573-2,394 ng/ml (urine) through the first postnatal month. Plasma and urine riboflavin and pyridoxine concentrations in enterally fed VLBW infants increased from baseline concentrations by 1 week of postnatal age and remained elevated for the first postnatal month. High daily intake and immature renal development are probable contributing causes of the elevated plasma riboflavin and pyridoxine concentrations. We suggest that lower daily enteral administration of riboflavin and pyridoxine should maintain adequate blood concentrations and minimize potential toxicity.

Thiamine, riboflavin, folate, and vitamin B12 status of infants with low birth Weights receiving enteral nutrition

The purpose of the present study was to monitor the vitamin status of 14 low-birth-weight (LBW) infants (< 1,750 g birth weight) at 2 weeks and an additional four infants at 3 weeks who were receiving an enteral formula providing 247 micrograms/100 kcal thiamine, 617 micrograms/100 kcal riboflavin, 37 micrograms/100 kcal folate, and 0.55 micrograms/100 kcal vitamin B12. The mean birth weight of the 18 infants was 1,100 +/- 259 g, and mean gestational age was 29 +/- 2 weeks. Weekly blood, 24-h urine collections, and dietary intake data were obtained. For thiamine, red blood cell (RBC) transketolase activity was within the normal range for all infants. For riboflavin, RBC glutathione reductase activity was normal for all infants except one. We calculated from intake and urinary excretion data that these infants require 225 micrograms/100 kcal thiamine and 370 micrograms/100 kcal riboflavin, respectively. Mean plasma folate levels were 21 +/- 11 ng/ml at 2 weeks and 18 +/- 5 ng/ml at 3 weeks. RBC folate levels were 455 +/- 280 ng/ml at 2 weeks and 391 +/- 168 ng/ml at 3 weeks. All folate blood values were normal, except for one subject with an elevated level (59 ng/ml). Vitamin B12 plasma values were 737 +/- 394 pg/ml at 2 weeks and 768 +/- 350 pg/ml at 3 weeks, and all values were normal except for three infants with elevated values. In conclusion, appropriate vitamin status was maintained during this short observational period, during administration of this enteral formula; however, riboflavin concentrations in the enteral feed may be excessive.

Microtitre-plate enzyme-linked ligand-sorbent assay of riboflavin (vitamin B2) in human plasma and urine

Enzyme-linked ligand-sorbent assay (ELLSA) of riboflavin was performed in standard, multi-well microtitre plates. 3-Carboxymethylriboflavin was carbodiimide-coupled to bovine serum albumin and the conjugate was adsorbed on the well surface. Riboflavin-binding protein from egg-white was biotinylated with biotinamidocaproate N-hydroxysuccinimide ester. The assay was based on competition of riboflavin analyte with the immobilized flavin for the biotinylated binder. Secondary adsorption of the biotinylated riboflavin-binding protein was measured by using avidin-bearing horseradish peroxidase label. The optimized method had a detection limit of 0.8 pmol of riboflavin and was expected to work within a riboflavin concentration range of 2 X 10(-8)(-4) X 10(-6) mol l-1. Preliminary trials suggested that ELLSA was suitable for determining riboflavin in human urine and the sum of riboflavin and flavin nucleotides in human plasma. The analytical performance of ELLSA for those materials was characterized by good consistency of the results with those obtained by conventional, fluorimetric methods, a mean recovery of riboflavin supplement of over 90% and a within-plate relative standard deviation below 20%. Some unique samples of both urine and plasma were assayed with between-plate relative standard deviations higher than 30%, implicating further modification of this version of ELLSA. The method intended for routine control determinations of vitamin B2 status in human subjects and is addressed to laboratories that routinely perform automated, microplate-based enzyme-linked assays.

Influence of the intake of fortified breakfast cereals on dietary habits and nutritional status of Spanish schoolchildren

A study was performed on the breakfast habits of 200 schoolchildren between 9 and 13 years of age. The subjects were classified into two groups: group C, children who consumed fortified breakfast cereals (65 boys and 35 girls), and group NC, children who did not (64 boys and 36 girls). The different dietary habits and the nutritional status of the two groups were analyzed. Haematological, biochemical, anthropometric, and dietary data were collected, the latter involving a 5-day food record. The children of the C group were found not only to have a more complete and nutritive breakfast, but also showed better dietary patterns for the rest of the day. Their lipid intake (% kJ) was lower and the carbohydrate intake (g/d and % kJ) higher than in the NC children. The intakes of thiamine, pyridoxine, folates, and beta-carotenes were also higher in group C. Better dietary habits were reflected in higher blood levels of some important compounds. Group C children had higher retinol, serum folate, and riboflavin levels than NC children. The percentage of children with hypercholesterolaemia (serum cholesterol > 4.5 mmol/l) was higher amongst those of the NC group: 37% as compared with 18% of the C children.

Vitamin status of healthy subjects in Burgundy (France)

A nutrition survey was conducted in Burgundy (France) with a population sample of 337 middle-aged and healthy subjects (157 males and 180 females) recruited at a health examination center in 1985-1986. The status of beta-carotene, thiamin, riboflavin, folate, vitamin B6, B12, C, A, D, and E was assessed by means of 7-day food records and biochemical studies. Results were compared with two other recent nutritional surveys conducted in France: ESVITAF (control group only) and Val de Marne surveys. The dietary information collected for each subject was compared to the 1992 French Recommended Dietary Allowances (FRDA). Dietary vitamin intakes were higher in males than in females. Low vitamin intakes (< 1/2 FRDA) were found in 5% of males and 7% of females for thiamin, in 11% of males and 28% of females for vitamin B6, in 6% of males and 3% of females for vitamin C, in 87% of males and 91% of females for vitamin D, and in 8% of males and 13% of females for vitamin E. No subject had a vitamin intake < 1/2 FRDA for riboflavin, folate, vitamins A and B12. ESVITAF and Val de Marne studies also show low vitamin intakes for vitamin B6, thiamin, riboflavin, vitamins D and E. Biochemical status was examined using erythrocyte enzyme function and blood vitamin levels. The percent of subjects with deficient biochemical values was high for vitamin B6 (15% of all males and 20% of all females), and vitamin D (13% of all males, and 15% of all females). With regard to thiamin, riboflavin, vitamin C, folate, vitamin B12, vitamin A, and vitamin E, < 5% of subjects had values in the range of major vitamin deficiency. However, in both genders, except for vitamin C and vitamin A (only for females), low values corresponding to a moderate risk of vitamin deficiency was high for most vitamins. The incidence of a severe deficient vitamin status for thiamin and riboflavin was higher in Val de Marne than in Burgundy, or ESVITAF. In Val de Marne, the probability of a moderate risk of vitamin deficiency was high for thiamin, riboflavin, vitamin B6, vitamin A and vitamin E. Our results (as other studies performed in France and in other industrialized countries) raise the issue of the health significance of marginally deficient vitamin status.

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

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.

Intrauterine vitamin B2 uptake of preterm and full-term infants

Intrauterine uptake of vitamin B2 in preterm and full-term infants was examined. Factors of influence on vitamin supply were considered. Forty-four women and their infants were included in the study. Fetal vitamin uptake was calculated as arteriovenous concentration gradient in cord plasma times umbilical plasma flow. Concentration of vitamin B2 (free riboflavin and flavocoenzymes) was determined by high performance liquid chromatography of placental tissue and blood plasma (maternal vein, umbilical artery, umbilical vein). Flavocoenzymes were analyzed as flavin mononucleotide after acid hydrolysis of flavin adenine dinucleotide. Umbilical plasma flow was measured using pulsed Doppler sonography. Both free riboflavin and flavocoenzymes were transferred from the maternal plasma to the umbilical vein, but only free riboflavin was accumulated (approximately 1:4 for preterm and full-term infants, respectively). Flavocoenzyme concentration was higher in the umbilical vein than in the umbilical artery (p < 0.05). This indicated a median uptake of flavocoenzymes of 1.5 nmol/min.kg in preterm infants and 0.4 nmol/min.kg in full-term infants (preterm versus full-term, p < 0.01). Fetal vitamin supply depended on umbilical plasma flow and on maternal vitamin status (the latter was shown only in full-term infants). No dependence on placental vitamin concentration was observed (p > 0.05). Concentration of free riboflavin was higher in umbilical artery than in umbilical vein (p < 0.05). This indicated a release of free riboflavin from fetal tissues independent of gestational age (0.4 nmol/min.kg, preterm; 0.2 nmol/min.kg, full-term; p > 0.05).

Biochemical factors in the lens opacities. Case-control study. The Lens Opacities Case-Control Study Group

OBJECTIVE

To evaluate associations with biochemical indicators of nutritional and other risk factors in the Lens Opacities Case-Control Study.

DESIGN

Case-control study.

SETTING AND PARTICIPANTS

The Lens Opacities Case-Control Study determined risk factors for cortical, nuclear, and posterior subcapsular opacities among 1380 participants aged 40 to 79 years.

DATA COLLECTION

Vitamin E, selenium, and biochemistry profile determinations were performed on all patients; red blood cell enzymes and amino acids were measured in systematic samples of about 25% of the Lens Opacities Case-Control Study population.

OUTCOME

Laboratory test values in cases and controls were compared and expressed as odds ratios and 95% confidence intervals.

RESULTS

In polychotomous logistic regression analyses controlling for age and sex, the risk of opacities was reduced to less than one half in persons with higher levels of vitamin E (odds ratio, 0.44 for nuclear opacities), albumin-globulin ratio (odds ratio, 0.41 for mixed opacities), or iron (odds ratio, 0.43 for cortical opacities); higher uric acid levels increased risk (odds ratio, 1.74 for mixed opacities). Persons with opacities were twice as likely to have high glutathione reductase activity (with flavin adenine dinucleotide), which suggests low riboflavin status (odds ratio, 2.13). Most odds ratios for amino acids were under unity and were significantly decreased for glycine (0.36) and aspartic acid (0.31).

CONCLUSIONS

Lens opacities were associated with lower levels of riboflavin, vitamin E, iron, and protein nutritional status. Higher levels of uric acid increased risk of mixed opacities. The findings for riboflavin, vitamin E, iron, and uric acid are compatible with the dietary intake and medical history results of the Lens Opacities Case-Control Study.

Changes of some vitamin levels during and after normal pregnancy

Most vitamin status parameters change significantly during pregnancy. A number of factors have been associated with this hypovitaminaemia of pregnancy. From our data, it was concluded that the initial value of a vitamin status parameter was by far the main determinant of the changes of vitamin levels during pregnancy: the higher the value, the steeper the decrease. Some hormonal variables were associated with these changes as well. This is highly suggestive of a resetting of vitamin homeostasis in blood, with a retention of vitamins in maternal tissues. The postpartum changes of vitamin levels provide insight into the 'net cost' of vitamins during pregnancy. Most serum blood levels of vitamins normalized shortly after delivery. Serum vitamin B6 levels increased slowly with 25% below the acceptable range at 6 months postpartum. However, the GGOT stimulation ratio, indicative for vitamin B6 cellular content, was completely normal at the time. Serum folacin was the only exception, with 45% serum levels in the marginal or deficient range; 20% of this group had deficient or marginal red cell folacin levels as well. This indicates that the 'net cost' of folacin during pregnancy is considerable, and repletion of folacin stores takes more than 6 months.