Supplementation during pregnancy with small-quantity lipid-based nutrient supplements or multiple micronutrients, compared with iron and folic acid, increases women's urinary iodine concentration in semiurban Ghana: A randomized controlled trial.

There is little information on whether prenatal multiple micronutrient (MMN) supplements containing iodine affect women's iodine status. In the International Lipid-based Nutrient Supplements DYAD-Ghana trial, we aimed to assess women's urinary iodine concentration (UIC, µg/L) during pregnancy, as one of the planned secondary outcomes. Women (n = 1,320) <20 weeks of gestation were randomized to consume 60 mg iron and 400 µg folic acid per day (iron and folic acid [IFA]); 18 vitamins and minerals including 250 µg iodine per day (MMN); or 20 g/day of small-quantity lipid-based nutrient supplements (LNS) with the same and additional 4 vitamins and minerals as the MMN (LNS). In a subsample (n = 295), we tested differences in groups' geometric mean UICs at 36 weeks of gestation controlling for baseline UIC and compared the geometric means (approximately median UICs) with the World Health Organization (WHO) cut-offs: median UIC <150, 150-249, and ≥500 reflecting low, adequate, and excessive iodine intakes, respectively. At baseline, overall median UIC was 137. At 36 weeks of gestation, controlling for baseline UIC, geometric mean (95% confidence interval) UICs of the MMN (161 [133, 184]) and LNS (158 [132, 185]) groups did not differ; both values were significantly greater (overall p = .004) than that of the IFA group (116 [101, 135]). The median UICs of the MMN and LNS groups were within the WHO "adequate" range, whereas that of the IFA group was below the WHO adequate range. In this setting, supplementation during pregnancy with small-quantity LNS or MMN providing iodine at the WHO-recommended dose, compared with IFA, increases the likelihood of adequate iodine status.

Glutathione-stabilized Cu nanoclusters as fluorescent probes for sensing pH and vitamin B1.

Glutathione (GSH), playing roles as both a reducing reagent and protecting ligand, has been successfully employed for synthesizing Cu nanoclusters (CuNCs@GSH) on the basis of a simple and facile approach. The as-prepared CuNCs exhibited a fluorescence emission at 600nm with a quantum yield (QY) of approximately 3.6%. Subsequently, the CuNCs described here was employed as a broad-range pH sensor by virtue of the fluorescence intensity of CuNCs responding sensitively to pH fluctuating in a linear range of 4.0-12.0. Meanwhile, these prepared CuNCs were applied for detections of vitamin B1 (VB1) on the basis of positively charged VB1 neutralizing the negative surface charge of CuNCs, thus leading to the instability and aggregations of CuNCs, and further facilitating to quench their fluorescence. In addition, the proposed analytical method permitted detecting VB1 with a linear range of 2.0×10(-8)-1.0×10(-4) mol L(-1) as well as a detection limit of 4.6×10(-9) mol L(-1). Eventually, the practicability of this sensing approach was validated by assaying VB1 in human urine samples and pharmaceutical tablets, confirming its potential to broaden avenues for assaying VB1.

Study of the influence of over-the-counter vitamin supplement intake on urine fluorescence to optimize cancer detection by fluorescence cystoscopy.

Fluorescence cystoscopy (FC) efficiently enhances the detection and improves the therapeutic management of early bladder cancer. During an FC, about 150 ml of water is needed to inflate the bladder. The water is quickly diluted by urine which can be fluorescent. If this bladder washout fluid (BWF) becomes fluorescent, the FC images are frequently degraded. Unfortunately, it is unclear which elements of the diet may contribute to this background fluorescence. We propose to start this exploration with over-the-counter (OTC) vitamin supplements. To this end, we measured excitation­emission matrices of urine samples and the kinetics of modifications of urine fluorescence obtained from nine healthy volunteers before, during, and after intake of a commercially available OTC vitamin supplement. The pharmacokinetics shows that the BWF fluorescence values reach a maximum 8 to 10 h after vitamin intake. They decrease in the half-day that follows and reach values close to baseline ~1 day afterward. Based on these results, we conclude that, in order to avoid degradations of fluorescence images, it is likely best that the intake of OTC vitamin supplements be avoided during the week preceding an FC.

A randomised cross-over pharmacokinetic bioavailability study of synthetic versus kiwifruit-derived vitamin C.

Kiwifruit are a rich source of vitamin C and also contain numerous phytochemicals, such as flavonoids, which may influence the bioavailability of kiwifruit-derived vitamin C. The aim of this study was to compare the relative bioavailability of synthetic versus kiwifruit-derived vitamin C using a randomised cross-over pharmacokinetic study design. Nine non-smoking males (aged 18-35 years) received either a chewable tablet (200 mg vitamin C) or the equivalent dose from gold kiwifruit (Actinidia chinensis var. Sungold). Fasting blood and urine were collected half hourly to hourly over the eight hours following intervention. The ascorbate content of the plasma and urine was determined using HPLC with electrochemical detection. Plasma ascorbate levels increased from 0.5 h after the intervention (P = 0.008). No significant differences in the plasma time-concentration curves were observed between the two interventions (P = 0.645). An estimate of the total increase in plasma ascorbate indicated complete uptake of the ingested vitamin C tablet and kiwifruit-derived vitamin C. There was an increase in urinary ascorbate excretion, relative to urinary creatinine, from two hours post intervention (P < 0.001). There was also a significant difference between the two interventions, with enhanced ascorbate excretion observed in the kiwifruit group (P = 0.016). Urinary excretion was calculated as ~40% and ~50% of the ingested dose from the vitamin C tablet and kiwifruit arms, respectively. Overall, our pharmacokinetic study has shown comparable relative bioavailability of kiwifruit-derived vitamin C and synthetic vitamin C.

Vitamin C supplementation in patients receiving peripheral parenteral nutrition after gastrointestinal surgery.

OBJECTIVE: We investigated an adequate vitamin C dose during peripheral parenteral nutrition therapy in patients after gastrointestinal surgery by measuring blood concentrations and urine excretions of vitamin C. We also sought to identify the effects of vitamin C on the oxidative status. METHODS: In a randomized trial, 2 d after undergoing gastrointestinal surgery, 16 patients started to receive a 5-d continuous intravenous infusion of vitamin C, either 100 or 500 mg/d. Blood concentrations of vitamin C and inflammatory and immunologic parameters were measured preoperatively, the day after surgery, and 3 and 5 d after starting administration of vitamin C (day 3 and day 5). Also, excretions of vitamin C and oxidative stress markers in 24-h, cumulative urine samples, collected and stored under light protection at 0°C, were measured on day 3 and day 5. RESULTS: Mean blood vitamin C concentration decreased markedly after surgery. The concentration returned to normal on day 3 and on day 5 in the 500-mg group and only on day 5 in the 100-mg group. Concentrations differed significantly between the groups on day 3 and on day 5 (P < 0.001 for both days). Urinary vitamin C excretion was above normal on both days in the 500-mg group, but it never reached normal in the 100-mg group (P < 0.001 for both days). Urinary excretion of 8-isoprostane, a marker of oxidative stress, was significantly lower in the 500-mg than in the 100-mg group on day 3 (P = 0.002). CONCLUSION: Vitamin C dose of 500 mg/d, not 100 mg/d, is adequate for patients undergoing gastrointestinal surgery and receiving peripheral parenteral nutrition therapy. Vitamin C may decrease postsurgical oxidative stress.

Selenium supplementation reduced oxidative DNA damage in adnexectomized BRCA1 mutations carriers.

Some experimental evidence suggests that BRCA1 plays a role in repair of oxidative DNA damage. Selenium has anticancer properties that are linked with protection against oxidative stress. To assess whether supplementation of BRCA1 mutation carriers with selenium have a beneficial effect concerning oxidative stress/DNA damage in the present double-blinded placebo control study, we determined 8-oxodG level in cellular DNA and urinary excretion of 8-oxodG and 8-oxoGua in the mutation carriers. We found that 8-oxodG level in leukocytes DNA is significantly higher in BRCA1 mutation carriers. In the distinct subpopulation of BRCA1 mutation carriers without symptoms of cancer who underwent adnexectomy and were supplemented with selenium, the level of 8-oxodG in DNA decreased significantly in comparison with the subgroup without supplementation. Simultaneously in the same group, an increase of urinary 8-oxoGua, the product of base excision repair (hOGG1 glycosylase), was observed. Therefore, it is likely that the selenium supplementation of the patients is responsible for the increase of BER enzymes activities, which in turn may result in reduction of oxidative DNA damage. Importantly, in a double-blinded placebo control prospective study, it was shown that in the same patient groups, reduction in cancer incidents was observed. Altogether, these results suggest that BRCA1 deficiency contributes to 8-oxodG accumulation in cellular DNA, which in turn may be a factor responsible for cancer development in women with mutations, and that the risk to developed breast cancer in BRCA1 mutation carriers may be reduced in selenium-supplemented patients who underwent adnexectomy.

Epidemiologic assessment of sugars consumption using biomarkers: comparisons of obese and nonobese individuals in the European prospective investigation of cancer Norfolk.

We have previously shown that urinary sugars excretion in 24 h urine collections can serve as an independent biomarker of sugars consumption. In the European Prospective Investigation of Cancer (EPIC) Norfolk study of nutrition and cancer, this biomarker in spot urines has been assessed in a cross-sectional comparison of 404 obese individuals aged 45 to 75 years with a body mass index (BMI) of >30 kg/m(2) and 471 normal weight individuals aged 45 to 75 years with a BMI of <25 kg/m(2). In individuals of normal weight, sucrose, protein, and vitamin C intake were positively and highly significantly related to biomarkers in spot urine or plasma (P < 0.001), but there were no significant associations between biomarkers and food intake reports in the obese. Odds ratios for a BMI of >30 were significantly elevated for urinary sucrose [trend per milligram per liter quintile, 1.13; 95% confidence interval (95% CI), 1.02-1.25; P = 0.016], and the odds ratio for urinary sucrose/fructose ratio was highly significant (trend per quintile, 1.264; 95% CI, 1.142-1.401; P < 0.001). No associations for sugars intake and obesity were found using a food frequency questionnaire, and dietary vitamin C was apparently associated with increased risk (P < 0.001) despite an inverse association for plasma vitamin C. Nutritional biomarkers of consumption can complement existing methods for assessing cancer risk from diet in epidemiologic studies.

A feasibility study quantifying in vivo human alpha-tocopherol metabolism.

BACKGROUND: Quantitation of human vitamin E metabolism is incomplete, so we quantified RRR- and all-rac-alpha-tocopherol metabolism in an adult. OBJECTIVE: The objective of the study was to quantify and interpret in vivo human vitamin E metabolism. DESIGN: A man was given an oral dose of 0.001821 micromol [5-14CH3]RRR-alpha-tocopheryl acetate (with 101.5 nCi 14C), and its fate in plasma, plasma lipoproteins, urine, and feces was measured over time. Data were analyzed and interpreted by using kinetic modeling. The protocol was repeated later with 0.001667 micromol [5-14CH3]all-rac-alpha-tocopheryl acetate (with 99.98 nCi 14C). RESULTS: RRR-alpha-tocopheryl acetate and all-rac-alpha-tocopheryl acetate were absorbed equally well (fractional absorption: approximately 0.775). The main route of elimination was urine, and approximately 90% of the absorbed dose was alpha-2(2'-carboxyethyl)-6-hydroxychroman. Whereas 93.8% of RRR-alpha-tocopherol flow to liver kinetic pool B from plasma was returned to plasma, only 80% of the flow of all-rac-alpha-tocopherol returned to plasma; the difference (14%) was degraded and eliminated. Thus, for newly digested alpha-tocopherol, the all-rac form is preferentially degraded and eliminated over the RRR form. Respective residence times in liver kinetic pool A and plasma for RRR-alpha-tocopherol were 1.16 and 2.19 times as long as those for all-rac-alpha-tocopherol. Model-estimated distributions of plasma alpha-tocopherol, extrahepatic tissue alpha-tocopherol, and liver kinetic pool B for RRR-alpha-tocopherol were, respectively, 6.77, 2.71, and 3.91 times as great as those for all-rac-alpha-tocopherol. Of the lipoproteins, HDL had the lowest 14C enrichment. Liver had 2 kinetically distinct alpha-tocopherol pools. CONCLUSIONS: Both isomers were well absorbed; all-rac-alpha-tocopherol was preferentially degraded and eliminated in urine, the major route. RRR-alpha-tocopherol had a longer residence time and larger distribution than did all-rac-alpha-tocopherol. Liver had 2 distinct alpha-tocopherol pools. The model is a hypothesis, its estimates are model-dependent, and it encourages further testing.

[The vitamins and minerals provision of children living in different ecological-biogeochemical zones in Chuvashia]. / Obespechennost' vitaminami i mineral'nymi veshchestvami detei, prozhivaiushchikh v razlichnykh ékologo-biogeokhimicheskikh zonakh Chuvashskoi respubliki.

The results of investigation about providing 96 children at the age of 11-12 with vitamins in different ecological-biogeochemical zones of Chuvashia are presented in this article. The actual nutrition of children was estimated, by questionnaire-weight Pokrovsky's method and the level of excretion of vitamins B1, B2 and ascorbic acid with urine was studied by fluorescent method. The deficiency of riboflavin (66% in girls and 97% in boys) and ascorbic acid deficiency (30% in children) was revealed in the daily ration, the quantity of thiamin was sufficient. The providing the organism of children with investigated vitamins is low in Chuvashia. There is the link between ecological-biogeochemical characteristics of Chuvashia and providing with vitamins B1, B2 and C, their quantity in food being the same.

Dietary intake in male and female smokers, ex-smokers, and never smokers: the INTERMAP study.

This report examines dietary intakes in smokers, ex-smokers, and never smokers in INTERMAP. The 4680 participants aged 40-59 years-from 17 population samples in four countries (China, Japan, UK, USA)-provided four 24-h recalls to assess nutrient intakes and two 24-h urine collections to assess excretion of urea, sodium (Na), potassium (K), etc. Compared to never smokers, current smokers generally consumed more energy from alcohol and saturated fats (SFA), less energy from vegetable protein and carbohydrates, less dietary fibre, vitamin E, beta carotene, vitamin C, thiamine, riboflavin, folate, vitamin B6, calcium, iron, phosphorus, magnesium (Mg), and K per 1000 kcal, excreted less K and urea (marker of dietary protein), had a lower ratio of polyunsaturated fat (PFA) to SFA intake, higher Keys dietary lipid score, and higher dietary and urinary Na/K. There were few differences between smokers and never smokers for total energy intake, energy from total and animal protein, monounsaturated fats, PFA, omega 3 and omega 6 PFA, dietary cholesterol, total vitamin A, retinol, vitamin D, vitamin B12, and urinary and dietary Na. Compared to ex-smokers, smokers generally consumed less energy from vegetable protein, omega 3 PFA, carbohydrates, less dietary fibre, beta carotene, vitamin E, vitamin C, thiamine, riboflavin, folate, vitamin B6, iron, phosphorus, Mg, had lower PFA/SFA, and excreted less urea and K. In conclusion, INTERMAP results are consistent with other reports indicating that smokers have less healthful diets than nonsmokers. Public health interventions in smokers should focus not only on helping them to quit smoking but also on improving their diets to further reduce cancer and cardiovascular disease risks.

[Analysis of vitamin and mineral sufficiency in children using data of consumption with food and urinary excretion]. / Otsenka obespechennosti detei vitaminami i mineral'nymi veshchestvami po dannym o postuplenii ikh s pishchei i ékskretsii s mochoi.

It has been shown that vitamin C and B2, calcium and phosphorus daily intake strongly correlated with their urinary excretion in children 5-8 years old (Moscow) from the decreased bone mineral density risk group. Hour urinary calcium, phosphorus, creatinine excretion values for adequately supplied children has been determined. Vitamin and mineral status evaluation by means of estimation of vitamins and minerals consumption and urinary level (except vitamin B2) give relatively coincided results. Difference between these methods of nutritive status assessment attains 8-25 per cent. Thus these methods are substituted for group nutritive status evaluation.

La bioquímica en los estudios de nutrición / Biochemical parameters and nutritional status

Los parámetros bioquímicos reúnen ventajas comparativas respecto a las observaciones clínicas, antropométricas y encuestas alimentarias ya que, debido a su característica de responder a alguna alteración medible y directamente relacionada al estado nutricional, se comportan como indicadores funcionales. Si una serie de indicadores funcionales se combinan en forma adecuada, constituyen una verdadera radiografía metabólica del momento en que se realiza el estudio y proporcionan perfiles nutricionales que permiten identificar a los individuos en situación de riesgo. Se detallan parámetros que permiten detectar tempranamente deficiencias globales o específicas, a fin de poder establecer una terapia racional basada en un diagnóstico certero

Megalin knockout mice as an animal model of low molecular weight proteinuria.

Megalin is an endocytic receptor expressed on the luminal surface of the renal proximal tubules. The receptor is believed to play an important role in the tubular uptake of macromolecules filtered through the glomerulus. To elucidate the role of megalin in vivo and to identify its endogenous ligands, we analyzed the proximal tubular function in mice genetically deficient for the receptor. We demonstrate that megalin-deficient mice exhibit a tubular resorption deficiency and excrete low molecular weight plasma proteins in the urine (low molecular weight proteinuria). Proteins excreted include small plasma proteins that carry lipophilic compounds including vitamin D-binding protein, retinol-binding protein, alpha(1)-microglobulin and odorant-binding protein. Megalin binds these proteins and mediates their cellular uptake. Urinary loss of carrier proteins in megalin-deficient mice results in concomitant loss of lipophilic vitamins bound to the carriers. Similar to megalin knockout mice, patients with low molecular weight proteinuria as in Fanconi syndrome are also shown to excrete vitamin/carrier complexes. Thus, these results identify a crucial role of the proximal tubule in retrieval of filtered vitamin/carrier complexes and the central role played by megalin in this process.

[Use of the magnitude of vitamin and vitamin metabolite excretion as indicators of availability of vitamins B2, B6, and niacin]. / Ob ispol'zovanie velichin ékskretsii vitaminov i ikh metabolitov v kachestve pokazatelei obespechennosti vitaminami B2, B6 i niatsinom.

Alimentary deficiency of riboflavin in rats caused a decrease in excretion of vitamin B2 with urine simultaneously with lowering in daily excretion of 4-pyridoxylic acid (4-PA) and N1-methyl nicotinamide (N1-MNA); these patterns are usually used as indicators of pyridoxine and niacin availability. The similar decrease in excretion of 4-PA and N1-MNA with urine but without alterations in NAD+NADP concentrations in erythrocytes was detected in women deficient in vitamin B2. Content of nicotinamide coenzymes in erythrocytes correlated with excretion of N1-MNA with urine only under normal conditions of riboflavin availability. Use of the criteria involving rates of 4-PA and N1-MNA excretion for evaluation of pyridoxine and niacin deficiency is discussed.

Metabolic changes in man under hypokinesia and physical exercise.

It was theorized that physical exercise may be used to prevent the development of metabolic changes in man under hypokinesia (diminished muscular activity). In this investigation we assessed the efficacy of physical exercise in attenuating metabolic disturbances in twelve physically healthy men aged 19 to 23 years under 100 days of hypokinesia and 15 days of a readaptation period. The subjects were divided into an experimental and a control group with six men each. The experimental group was subjected to combined hypokinesia and physical exercise and the control group to pure hypokinesia (that is, without the use of any preventive measures). The actual experimental period was preceded by a period to establish baseline values. Both groups of men were on a diet that consisted of about 2700 kcal/day. For the simulation of the hypokinetic effect the men were kept under a liberal bed rest regimen. During the background period, hypokinetic period, and readaption period, several biochemical parameters were measured. Energy requirements were found to be suppressed, protein metabolism impaired, loss of nitrogenous products increased, fluid and electrolyte excretion accelerated, vitamin elimination was enhanced, corticosteroid blood concentration decreased, and hemoglobin and cell counts increased. It was concluded that hypokinesia caused marked debilitating metabolic changes in man. Physical exercise failed to counteract effectively the development of adverse reactions in the examined parameters under hypokinesia.

[Biochemical markers of vitamin supply]. / Marqueurs biochimiques d'apport vitaminique.

The biochemical indicators to assess the nutritional status of individuals may be divided into 4 categories: methods which measure body stores e.g. plasma vitamin C or urinary excretion of thiamine, methods related to the rate of conversion of vitamins to metabolites e.g. thiamine pyrophosphate content of blood or urinary excretion of pyridoxic acid, methods based on the coenzymatic or hormonal function of vitamin metabolites, e.g., erythrocyte transketolase in the case of vitamin B1 or plasma concentration of 1,25 dihydroxycholecalciferol in the case of vitamin D. Finally, methods derived from true biochemical impairment of the metabolism, e.g., elevated blood pyruvate in borderline vitamin B1 deficiency or prolonged blood clotting time in the case of vitamin K deficiency. The results of all of these methods are for a certain vitamin related to each other and also to the daily intake of the vitamin in question as long as the daily vitamin intake remains stationary and no confounding variables such as disease, smoking or drinking habits interfere. Otherwise the estimation of vitamin intake by measuring biochemical parameters becomes questionable, since biochemical parameters are indicators of nutritional status and not so much of nutrient intake.