Homocysteine lowering effect of different multivitamin preparations in patients with end-stage renal disease.

OBJECTIVE: Hyperhomocysteinemia occurs in nearly 100% of patients with end-stage renal disease (ESRD) and is associated with increased morbidity and mortality. Means to reduce elevated homocysteine concentrations is supplementation with folic acid, vitamin B6, and vitamin B12. However, doses of vitamins required for optimized treatment are subject of debate. Therefore, the effect of 2 different multivitamin preparations on the homocysteine concentrations in patients with ESRD were compared. DESIGN: Patients received 3 times per week either 2 tablets of preparation A (800 microg folic acid, 6 microg vitamin B12, 10 mg vitamin B6), 2 tablets of preparation B (160 microg folic acid, no vitamin B12, 10 mg vitamin B6), or placebo for a period of 12 weeks with control of total homocysteine (tHcy) levels at baseline, and at 4, 8, and 12 weeks. SETTING: The study was performed at the University Hospital of Magdeburg, Germany in patients with ESRD treated with chronic intermittent maintenance hemodialysis. RESULTS: Preparation A reduced the tHcy concentration significantly by nearly 50%, whereas preparation B did not change the tHcy concentration in comparison with placebo. However, tHcy was not normalized in the majority of patients receiving preparation A. CONCLUSION: The reduction of tHcy achieved by a multivitamin containing 800 microg folic acid was substantial and even higher than the reduction reported in supplementation studies using higher doses of folic acid alone. Nevertheless, hyperhomocysteinemia in ESRD patients appears relatively refractory to vitamin supplementation, in contrast with results obtained in healthy volunteers.     

Gas-liquid chromatographic determination of vitamin D in multivitamin preparations containing excess amounts of vitamin E.

Gas-liquid chromatographic (GLC) determination of vitamin D in multivitamin preparations containing excess amounts of vitamin E (a more than 2,500 weight ratio of dl-alpha-tocopheryl acetate to vitamin D) was investigated and a simplified routine method was established because the method reported previously (1) could not be applied to such special preparations. After applying the unsaponifiable matters of a sample to a phosphate-treated alumina column chromatography prepared according to MULDER et. al. (2), the eluate was evaporated and the residue was subjected to thin-layer chromatography (TLC) and GLC. When this method was applied to model preparations made by mixing vitamin D2 and dl-alpha-tocopheryl acetate (excess amounts), good results were obtained. Since the results on a commercial multivitamin preparation containing excess amounts of vitamin E were also satisfactory, it was confirmed that the proposed method could be used for simplified routine determinations.     

High-performance liquid chromatographic determination of vitamin D in foods, feeds and pharmaceuticals by successive use of reversed-phase and straight-phase columns

A simplified and accurate method for the determination of vitamin D in foods, feeds and pharmaceuticals was established by high-performance liquid chromatography (HPLC) using successively reversed-phase and straight-phase columns. About 1-2 g of a sample was accurately weighed and directly saponified. The extracted unsaponifiable matter was subjected to preparative HPLC using a reversed-phase column and a vitamin D fraction was collected. The fraction was subsequently subjected to analytical HPLC using a straight-phase column and vitamin D was assayed by estimating the peak height. The proposed method was applied to various kinds of samples, e.g., fishery products, fish meals, mixed feeds for fish farming and chicken farming, egg yolk, milk products, cattle liver, Shiitake, fortified foods and multivitamin preparations. The results showed that the proposed method was useful for the determination of vitamin D in such samples, because the peak of vitamin D in the profile of the second HPLC was always clearly separated from other concomitants and good recovery was obtained. Therefore, we think that the method is useful as a routine one for the determination of vitamin D in foods, feeds and pharmaceuticals.     

Multivitamin supplementation in oral contraceptive users.

The effects of oral contraceptives (OC) containing 30 micrograms of ethinyl oestradiol and of subsequent multivitamin and folic acid supplementation on vitamin A, total B2 [including its three individual constituents, i.e. riboflavine, RB; flavine-mono-nucleotide, FMN; and flavine-adenine-dinucleotide, FAD], B12, C and folate concentration in serum and red blood cells have been studied in a group of 59 non-pregnant female volunteers. The group taking OC comprised 28 women while 31 women were included in the group of non-OC users serving as the controls. The women were studied for four cycles. Blood samples were taken on days 3 and 23 of the first cycle to obtain baseline values of each analyte. Multivitamin and folic acid supplementation started on day 1 of the second cycle and this was continued daily throughout three consecutive cycles until the end of the study. Vitamin A levels were significantly higher and vitamin B12 levels were significantly lower in the group using OC. Comparison of the baseline values of vitamin total B2, FAD, C, serum and red blood cell folate as determined on days 3 and 23 of the first cycle of the two groups compared revealed no significant differences. Multivitamin and folic acid supplementation did not affect the concentrations of vitamin A and vitamin B12 with either group, whereas all other vitamins increased significantly in both groups. The consistency of each effect of multivitamin supplementation between the two groups was also tested. The degree of these effects was not statistically different between both groups. The results suggest that the vitamin status is indeed affected by OC treatment, but the effects of multivitamin supplementation are not different in OC and non-OC users. Supplementation during OC use or just after discontinuing treatment cannot be justified for healthy young women. However, in the case of women with a critical vitamin balance or higher folate needs, multivitamin supplementation may be considered.     

Development of a HPLC method for the simultaneous determination of several B-vitamins and ascorbic acid

In cognizance of the difficulties involved in the colorimetric and titrimetric methods for the determination of individual vitamins, this laboratory has been carrying out a series of studies into the use of HPLC for improved analysis of these nutrients. Preliminary studies have been carried out for the determination of four B-vitamins. The present paper reports on further improvements made to enable the simultaneous determination of eight vitamins i.e. B1, B2, B6, B12, C, niacin, niacinamide and folic acid. Trials were carried out to determine the most suitable chromatographic system include changing the proportion of methanol in the mobile phase, the use of different ion-pairing reagents and other additives such as triethylamine and ammonia. Three sets of HPLC mobile phase systems are proposed to enable successful separation of all eight vitamins in less than 20 minutes, varying slightly with the type of ion-pairing reagent and mobile phase additive. This laboratory is currently carrying out trials to determine if the developed methods could be used for the determination of pharmaceutical products and food samples.     

New Food and Drug Administration requirements for inclusion of vitamin K in adult parenteral multivitamins

The newly amended requirements by the Food and Drug Administration (FDA) for an effective adult parenteral multivitamin drug product increase the amounts of vitamins B1, B6, C, and folic acid currently in the product to better meet estimated needs, and specifies the inclusion of 150 microg of vitamin K. Infuvite Adult Multiple Vitamins for Infusion is the first adult parenteral multivitamin product to meet the revised FDA requirements. The inclusion of vitamin K in adult parenteral multivitamin products is intended to afford patients a consistent daily supply of vitamin K approximating usual levels of intake. This is a change to clinical practice in the United States, where vitamin K has not been included in adult parenteral vitamin preparations, and physicians prescribe vitamin K separately. The reformulation of adult parenteral multivitamins required by the FDA raises questions about the potential impact that inclusion of vitamin K will have on patient management. One clinical practice change is that patients on parenteral nutrition receiving Infuvite Adult should no longer need weekly subcutaneous (SC) or intramuscular (IM) vitamin K injections. In addition, the consistent and modest level of vitamin K provided by the reformulated adult parenteral multivitamins may make it easier for physicians to maintain the desired level of hypoprothrombinemia (low levels of prothrombin) in those patients also on anticoagulant therapy with warfarin. However, for physicians accustomed to administering vitamin K separately, it is important to highlight that it may be more difficult to titrate anticoagulant therapy, especially among patients receiving dual feeding or vitamin K from another source. If marketed globally, these clinical practice issues may be more pronounced outside of the United States, where dual feeding is common, and patients may receive vitamin K from other sources.     

Gas-liquid chromatographic determination of vitamin D in multivitamin preparation.

Gas-liquid chromatographic (GLC) determination of vitamin D in multivitamin preparations was investigated and a simple routine method was established. The unsaponifiable matters of a sample was applied to a thin-layer chromatography (TLC) plate using Kieselgel GF254 as an adsorbent and a mixture of n-hexane-ethyl acetate (4:1) as a developing solvent. The scraped zones corresponding to vitamin D and previtamin D were extracted and determined by GLC using 1.5% OV-17 packed on Shimalite W (80-100 mesh) as a stationary phase. When the proposed method was applied to model preparations made by mixing vitamin D, A and E, it was confirmed that the determination of vitamin D was possible when the ratios of vitamin A and E (DL-alpha-tocopheryl acetate) to vitamin D were within 104 (I.U. ratio) and 2,500 (weight ratio), respectively. Since the ratios of most of commercial multivitamin preparations on sale in Japan are within the limitations and the results on multivitamin preparations were also satisfactory, the proposed method was confirmed to be suitable simple routine.     

Understanding optimal nutrition among women of childbearing age in the United States and Puerto Rico: employing formative research to lay the foundation for national birth defects prevention campaigns

Neural tube defects (NTDs) are serious birth defects of the brain and spine that affect approximately 3,000 pregnancies in the United States each year and affected 404 pregnancies in Puerto Rico from 1996 to 2002. Consuming the B vitamin folic acid can reduce the incidence of NTDs 50%-70%, and recent efforts to reduce NTD rates have focused on increasing the number of childbearing-aged women who take a vitamin containing folic acid every day. As the first stage of formative research in campaign planning, two exploratory, qualitative studies were conducted in order to (a) understand the complexity of vitamin use among women in the United States and Puerto Rico and (b) serve as a foundation on which to develop national communication and education interventions. Also, this information shed light on theories that might be used to guide campaign development. Results indicated that campaign messages designed to increase folic acid use through multivitamin supplementation in the United States must address women's barriers to vitamin use (e.g., cost, time), increase women's perceived need for multivitamins (e.g., identify immediate, tangible results from taking a daily multivitamin), and address the relationship between daily food choices and the need for supplementation. Future campaign messages in Puerto Rico must focus on many of these same issues, in addition to increasing women's knowledge about when folic acid should be taken in relation to pregnancy and addressing women's perceptions that vitamins cause weight gain (an undesirable outcome for most participants). The practical and theoretical implications of these results are discussed in terms of their contribution to the development of a creative new approach to increase multivitamin consumption among women of childbearing age in the United States and Puerto Rico.     

Folic acid and multivitamin supplement use and risk of placental abruption: a population-based registry study

The authors investigated a possible association of supplemental folic acid and multivitamin use with placental abruption by using data on 280,127 singleton deliveries recorded in 1999-2004 in the population-based Medical Birth Registry of Norway. Odds ratios, adjusted for maternal age, marital status, parity, smoking, pregestational diabetes, and chronic hypertension, were estimated with generalized estimating equations for logistic regression models. Use of folic acid and/or multivitamin supplements before or any time during pregnancy was reported for 36.4% of the abruptions (0.38% of deliveries) and 44.4% of the nonabruptions. Compared with no use, any supplement use was associated with a 26% risk reduction of placental abruption (adjusted odds ratio = 0.74, 95% confidence interval: 0.65, 0.84). Women who had taken folic acid alone had an adjusted odds ratio of 0.81 (95% confidence interval: 0.68, 0.98) for abruption, whereas multivitamin users had an adjusted odds ratio of 0.72 (95% confidence interval: 0.57, 0.91), relative to supplement nonusers. The strongest risk reduction was found for those who had taken both folic acid and multivitamin supplements (adjusted odds ratio = 0.68, 95% confidence interval: 0.56, 0.83). These data suggest that folic acid and other vitamin supplementation during pregnancy may be associated with reduced risk of placental abruption.     

Development of a high-performance anion-exchange chromatography with pulsed-amperometric detection based quantification assay for pneumococcal polysaccharides and conjugates

A method, using high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAEC-PAD), has been developed to determine the concentrations of Streptococcus pneumoniae capsular polysaccharides and polysaccharide conjugates used in formulating a conjugate vaccine for the prevention of pneumococcal infections. In an effort to determine optimum hydrolysis conditions for the analysis, pneumococcal polysaccharides were subjected to three different hydrolysis methods: trifluoroacetic acid (TFA) hydrolysis, methanolysis followed by TFA hydrolysis, or hydrofluoric acid (HF) hydrolysis followed by TFA hydrolysis. For quantification purposes, best results were obtained by methanolysis followed by TFA hydrolysis for uronic acid-containing polysaccharides, and by TFA hydrolysis for all the others.For the quantification of all the polysaccharides (from native to conjugated forms), a monosaccharide reference mixture (Rha, Gal and GlcA) hydrolyzed along with the samples can be used as standards for routine analysis. This is much more convenient than to hydrolyze a well-characterized reference polysaccharide (necessary standard only for type 1 capsular polysaccharide).This method is rapid, very sensitive (less than 10 microg of polysaccharide is required), and may replace advantageously the currently used colorimetric assays used to determine polysaccharides content. Moreover, it can be readily adapted for use with other bacterial polysaccharide preparations as well.     

An in vitro method for estimating biologically available vitamin B6 in processed foods

1. An in vitro method which used enzymic digestion of the food matrix to release biologically available vitamin B6 is described. 2. Vitamin B6-fortified liquid model foods were thermally processed. After these foods had been freeze-dried, one part was subjected to enzymic hydrolysis at pH 2.0 with pepsin (EC 3.4.23.1) followed by a hydrolysis at pH 8.0 with pancreatin. The vitamins that were found in the supernatant fraction, after an acidified methanol treatment of the hydrolysate, were estimated by high-performance liquid chromatography (HPLC). The other part was given to rats who were kept on a vitamin B6-depleted diet. 3. The biologically available vitamin B6 content of the processed model foods, as determined by rat bioassay, showed good correlation with the vitamin B6 determined by HPLC. 4. It has proved possible to use this in vitro, two-stage enzymic digestion system followed by HPLC determination to determine biologically available vitamin B6 in vitamin B6-fortified processed model foods.     

Factors influencing homocysteineamia in type 2 diabetic patients

Previous studies have suggested that hyperhomocysteinaemia (Hcy) could be a strong and independent cardiovascular risk factor. Many factors could influence the serum concentration of Hcy such as vitamin B 12, folic acid, renal failure, hypothyroid status, ovarian failure and cancers. So the aim of our study was to evaluate the prevalence of hyperhomocysteinaemia among 54 type 2 diabetic patients and to study, its relationship with vitamin B12, folic acid and Metformin. Were excluded all patients with an evident cause of hyperhomocysteinaemia. Mean age of patients was 52.8 years. Mean Hcy was 11.7 + 6.9 micromol/l. The prevalence of hyperhomocysteinaemia was 27.8% in our group. There were eight (14%) patients with vitamin B12 deficiency and three among them had hyperhomocysteinaemia. There was no folic acid deficiency and no relationship with Metformin treatment. We suggest a wide screening of hyperhomocysteinaemia in type 2 diabetic patients and folic acid or vitamin B12 supplements if necessary.     

Assessment of vitamins and minerals intake with supplements in pregnant women

The aim of the work was to assess the application of diet supplements in pregnant women, as well as the intake of vitamins and minerals with pharmaceuticals. Sixty women in age 19 - 40 years coming from the Mazowsze district were examined. The information about applying supplements was obtained using questionnaire method. The intake of vitamin and mineral supplements before and during pregnancy was declared on the level of 55% and 98.3% respectively. The average intake of vitamin D (157%), folic acid (128%), vitamin B2 (125%), vitamin C (121%), iron (120%), iodine and zinc (113%) from supplements was above recommended values. The average intake of vitamin B1, B12 and B6 from supplements was about 95-105% of RDA. The lowest average consumption was noted for vitamin A (60%) as well as calcium and magnesium (10-12% of recommended value). Pregnant women who have lived in country consumed less vitamins and minerals from supplements, however differences were statistically significant in case vitamin A, E, magnesium, cooper, iodine and manganese.     

Sparing effect of folic acid deficiency on the development of vitamin B12 deficiency in baboons fed a vitamin B12 deficient diet.

The effect of a vitamin B12 and folic acid deficient diet on juvenile and adolescent baboons (Papio cynocephalus anubis) was studied. The baboons developed clinical and hematological signs characteristics of folacin deficiency, although they were less severe in juvenile baboons. The signs disappeared when folic acid was replaced in the diet. The serum vitamin B12 levels increased in all baboons fed the vitamin B12 and folic acid deficient diet. When folic acid was added to the diet, the levels gradually decreased in adolescent baboons, liver vitamin B12 levels decreased to a lesser extent when fed a vitamin B12 and folic acid deficient diet than when fed a vitamin B12 deficient diet. In juvenile baboons fed a vitamin B12 and folic acid deficient diet, for 7 months and a vitamin B12 deficient diet for a further 11 months, liver vitamin B12 levels did not decrease at any time but were similar to those in baboons fed a vitamin B12 and folic acid supplemented diet.     

Developing Effective Campaign Messages to Prevent Neural Tube Defects: A Qualitative Assessment of Women's Reactions to Advertising Concepts

The incidence of neural tube defects (NTDs), serious birth defects of the brain and spine that affect approximately 3,000 pregnancies in the United States each year, can be reduced by 50–70% with daily periconceptional consumption of the B vitamin folic acid. Two studies were designed to assess college women's reactions to and perceptions of potential campaign advertising concepts derived from preproduction formative research to increase folic acid consumption through the use of a daily multivitamin. Study one assessed draft advertising concepts in eight focus groups (N = 71) composed of college-enrolled women in four cities geographically dispersed across the United States. Based on study one results, the concepts were revised and reassessed in study two with a different sample (eight focus groups; N = 73) of college women in the same four cities. Results indicated that participants generally responded favorably to concepts in each of the two studies, and provided insight into individual concepts to increase their overall appeal and effectiveness. The specific findings and implications of these results are discussed.     

Low serum folic acid levels in a nursing home population: a clinical experience.

Four hundred fifty-five residents of the Wisconsin Veterans Home had fasting serum specimens obtained for folic acid as part of standard practice. Twenty-nine percent were taking folic acid supplements. Six percent (n = 28) were taking phenytoin, a folate antagonist. No resident receiving a folate supplement (400 mcg/day) had a low serum folic acid level. This finding may be important for practitioners selecting a dose of folic acid for nursing home patients. Of the 325 residents not receiving a folate supplement, nine (3%) had low folic acid levels (< 2.5 ng/mL). Two of the nine were receiving phenytoin. Five were characterized by staff as eating well. As low serum levels are preventable with a multivitamin, we believe that supplementation with a multivitamin containing 400 mcg folic acid/day should be considered in nursing home residents.     

Socio-demographic, lifestyle, gynecological, and obstetric predictors of serum or plasma concentrations of homocysteine, folic acid, and vitamins B12 and B6 among low-income women in São Paulo, Brazil

This study examined the socio-demographic, lifestyle, gynecological, and obstetric factors associated with serum or plasma concentrations of homocysteine, folic acid, and vitamins B12 and B6 among low-income women in S?o Paulo, Brazil. Serum concentrations of folic acid and vitamin B12 were measured by fluoroimmunoassay, while plasma vitamin B6 and homocysteine levels were measured by reversed-phase high performance liquid chromatography. Independent variables were initially selected by Pearson correlation or Kruskal-Wallis test (p < 0.20). Based on cut-off values, altered concentrations of homocysteine, folic acid, and vitamins B12 and B6 were found in 20%, 6%, 11%, and 67% of participants, respectively. Age was positively correlated with vitamin B6 and homocysteine plasma concentrations (p < 0.001). Body mass index was positively correlated with vitamin B6 plasma concentration (p < 0.001). Multiple linear regression models accounted for 10.2%, 5.8%, 14.4%, and 9.4% of folic acid, vitamins B12 and B6, and homocysteine plasma or serum concentrations, respectively. In this study, socio-demographic, lifestyle, gynecological, and obstetric variables showed important predictive value for serum or plasma levels of the biochemical indicators assessed.     

Folate: a key to optimizing health and reducing disease risk in the elderly

Inadequate folate status is associated with an increased risk for chronic diseases that may have a negative impact on the health of the aging population. Folate, a water-soluble vitamin, includes naturally occurring food folate and synthetic folic acid in supplements and fortified foods. Inadequate folate status may result in hyperhomocysteinemia, a significant risk factor for atherosclerotic vascular disease, changes in DNA that may result in pro-carcinogenic effects and increased risk for cognitive dysfunction. Folate status may be negatively influenced by inadequate intake, genetic polymorphisms and interactions with various drugs. In the US, folic acid is now added to enriched grain products and continues to be included in the majority of ready-to-eat breakfast cereals. Recent data indicate that the folate status in the US population has improved significantly, presumably due to the effects of fortification. Folic acid (not food folate) intake in excess of the Tolerable Upper Intake Level may mask the diagnosis of a vitamin B(12) deficiency, which is more prevalent in the elderly than younger individuals. When folic acid supplements are recommended, a multivitamin that includes vitamin B(12) should also be advised. To safely and effectively increase folate intake in the elderly, naturally occurring folate-rich food sources should be promoted. Folate-rich foods include orange juice, dark green leafy vegetables, asparagus, strawberries and legumes. These foods are also excellent sources of other health-promoting nutrients associated with chronic disease risk reduction.     

超高效液相色谱法同时测定维生素强化食品中多种水溶性维生素

目的建立可同时测定维生素强化食品中7种水溶性维生素的超高效液相色谱法。方法采用梯度洗脱超高效液相色谱法，Waters ACQUITY UPLC^TM BEH C18柱（2．1mm×50mm，1．7μm），流动相A为辛烷磺酸钠0．8g／L水溶液（冰乙酸调pH=2．8）；B为甲醇，检测波长270nm，流速0．4ml／min。结果各种维生素含量测定方法的线性关系良好，r=0．9992—0．9998，回收率98．1％～100．2％，RSD=0．17—0．72。用该法测定了市售维生素饮料和维生素强化食品中维生素的含量，结果准确。结论本方法操作简便，分析速度快，灵敏度高，精密度好，结果准确可靠。     

Adequacy of prenatal care as a major determinant of folic acid, iron, and vitamin intake during pregnancy

This study aimed to quantify the association between adequacy of prenatal care and prevalence of folic acid, iron, and multivitamin intake during pregnancy. Data were obtained on socio-demographics, prenatal care, pregnancy complications, and use of vitamin/mineral supplements for 836 women, using a postpartum interview. Associations with the use of vitamin/mineral supplements were quantified with risk ratios (RR), computed by generalized binomial regression. A high proportion of women reported the use of folic acid (81.9%), iron (55.4%), and multivitamins (76.2%) as supplements during pregnancy. Use of supplements was independently associated with adequacy of prenatal care (adequate vs. inadequate: folic acid, RR = 2.28; 95%CI: 1.58-3.29; iron, RR = 1.99; 95%CI: 1.57-2.52, multivitamins, RR = 1.97; 95%CI: 1.54-2.51). Higher schooling was also associated with increased use of folic acid (RR = 1.42; 95%CI: 1.18-1.70), but not multivitamins (RR = 0.87; 95%CI: 0.77-0.98). Use of folic acid was less prevalent in single women (RR = 0.67; 95%CI: 0.48-0.95) and during unplanned pregnancies (RR = 0.81; 95%CI: 0.71-0.92). Adequacy of prenatal care is a major determinant of vitamin/mineral intake during pregnancy.