Behavior Of Vitamin Research Articles

Skin surface lipids photo‐oxidation: A vibrational spectroscopy study

AbstractSkin surface lipid (SSL) film is a mixture of sebum and epidermal lipids protecting the skin from the effects of the environment such as solar radiation. SSLs are a suitable target and scavenger for all reactive oxygen species (ROS) generated in the skin. In the SSLs, vitamin E has been identified as one of the main antioxidants that can capture ROS. This paper is the third part of a global study that evaluates the effect of solar radiation on the lipid classes that constitute SSLs. In the first two parts, the effect of solar radiation on fatty acids and triglycerides was studied using vibrational spectroscopy. In this part, the effect on the other lipid classes such as squalene (SQ), cholesterol (Chol), and wax ester (WE) (Palmitoleyl Palmitate) was studied and then the behavior of vitamin E under solar radiation was monitored. Finally, SSLs were irradiated and analyzed using vibrational spectroscopy and HT‐GC/MS to respectively follow the oxidation process and to identify the first target of solar radiation in SSLs. When irradiated alone, SQ oxidation process was detectable only after 2430 J/cm2 dose. Similar observations were obtained for vitamin E (after 1620 J/cm2). No changes were observed on the cholesterol and on the wax ester (Palmitoleyl Palmitate). In contrast, when extracted human SSLs film was irradiated, the more marked modifications were observed on SQ. This confirmed the antioxidant role of SQ by scavenging free radicals generated from the oxidation of polyunsaturated fatty acids (PUFA).

Vitamin D supplementation on anemia markers and the impact on PTH in patients with chronic kidney disease

Chronic Kidney Disease (CKD) is an injury that causes progressive impairment of exocrine and endocrine renal functions. A very common complication is anemia, caused by reduced erythropoietin production, iron deficiency and inflammation. Evidence demonstrates that vitamin D has effects on anemia of inflammation, through the increase in erythrocytes and decrease in pro-inflammatory cytokines. This study aims to review the effects of vitamin D supplementation on 25(OH)D2 concentrations, on anemia markers and on PTH levels. This is an integrative review carried out through the search and selection of original publications, in english and portuguese, indexed in PubMed, Web of Science and Science Direct databases belonging to the 2010-2020 range. The results pointed to 25(OH)D2 concentrations compatible with normality after vitamin D supplementation. In five studies, there was no change in hemoglobin and PTH levels, and in four studies there was a reduction in the dose of EPO or erythroid stimulating agent, attributing such effect on the role of calcitriol as a substrate for bone marrow erythropoietic cells. The study concluded that vitamin D supplementation had beneficial effects for correction of 25(OH)D2 deficiency, however, it reinforces the controversy about the behavior of vitamin D on the improvement of anemia markers and PTH levels in patients with DRC. Therefore, it is suggested that the beneficial effect of vitamin D on anemia in renal patients may be independent of PTH suppression.

Solubility Enhancement of Vitamins in Water in the Presence of Covitamins: Measurements and ePC-SAFT Predictions

Scarce knowledge on the behavior of vitamins in aqueous solutions in the presence of additives is often a limiting factor for industrial applications such as process design and optimization. Knowing the pH-solubility profiles of vitamins is fundamental for understanding and controlling their behavior in aqueous solutions. In the present work, pH-dependent solubilities of the vitamins ascorbic acid (VC), riboflavin (VB2), nicotinic acid (VB3acid), folic acid (VB9), and cyanocobalamin (VB12) were measured at T=298.15 K and p=1 bar. These results were compared with the pH-solubility profiles obtained with modified Henderson-Hasselbalch equations using pKa values from the literature. Further, the solubilities of poorly soluble VB2, VB9, and VB12 were increased by the addition of covitamins VC, VB3acid, and nicotinamide (VB3amide). As observed, VB3amide increases the vitamin solubility much stronger than VC and VB3acid. These covitamins are called “hydrotropes” in several works of literature, and they increase...

Characterization of partitioning behavior of vitamins in micellar systems using affinity capillary electrophoresis

Introduction: Micellar Electrokinetic Chromatography, sometimes referred as Affinity Capillary Electrophoresis, is a useful tool to the characterization of the drug partitioning in different vehicle systems such as micelles and microemulsions using the capacity factor as hydrophobicity parameter. Bile acids, because of their important role in biological systems, are applied widely in ACE method to characterization of partition properties of solutes. In this paper the interaction of some hydrophilic and lipophilic vitamins with micellar systems consisted of bile salts and phospholipids was considered using ACE. Material and Methods: Three mixed micelles and one microemulsion were employed. The samples were filtered through a 0.45 μm filter. 13 vitamins, consist of 4 lipophilic and 9 hydrophilic vitamins were investigated. Each vitamin was solved in different micellar systems (0.1 mg/ml). Then, using ACE, the electropherogram of samples was obtained under certain run conditions. The capacity factor for each sample was calculated according the migration times in the electropherogram. DMSO and Sudan red were used as EOF tracer and micelle tracer respectively. All experiments were carried out with certain instrumental conditions. Results and Discussion: The results show that the migration times of lipophilic vitamins are equal to migration time of micellar tracer and consequently the capacity factor of all of them tends to infinity. In fact these vitamins, concerning the hydrocarbonic chain in their chemical structure, are incorporated in the inner oil core of mixed micelle or microemulsion and moved with it. Four hydrophilic vitamins (niacinamid, pyridoxine, D-panthenol and cyanocobalamin) have different affinity to Micellar systems. But for each vitamin the affinity to different system is almost same. K′ zero means that vitamin has not any affinity to micelle, remains in aqueous phase and moves with EOF. Five hydrophilic vitamins (ascorbic acid, folic acid, riboflavin, biotin and thiamin) had charged behavior. The electrophoretic mobility of all these vitamins was negative, except thiamin which has positive mobility. Two important parameters that may influence these migration behaviors of charged solutes are pH and micelle concentration. Distribution properties of molecules mostly change depending to pH value of the media because of the effect of pH on the chemical interaction. In the other hand, it might be that the negative charge of bile salt's micelle increases by mixing with phospholipids, and causes to stronger repulsion between negative charged micelle and anion analyte. So the electrophoretic mobility of anionic vitamins in presence of micelle would be reduced. Conclusion: The MEKC technique as a method of ACE was employed to determination partitioning pattern of various kinds of vitamins in a micellar solutions. The affinity of both hydrophilic and lypophilic vitamins to micellar system was investigated by calculation the capacity factor. This value for lypophilic vitamins is infinite, because they incorporate with micelle compositions and moved with them. In contrast hydrophilic vitamins exhibited different partitioning behaviour in micellar solution. The negative value obtained for anionic hydrophilic vitamins can be corrected by change some condition like micellar concentration and the pH of media.

Serum Levels Of Vitamin D In Patients Undergoing Hematopoietic Stem Cell Transplantation

IntroductionThere are few studies on the behavior of vitamin D in patients undergoing Hematopoietic Stem Cell Transplantation (HSCT), although vitamin D serum levels are associated with use of corticosteroids and immunosuppressive drugs. In some studies, vitamin D deficiency in patients after HSCT is associated with reduced bone density, increased of parathyroid hormone and GVHD. ObjectivesTo study vitamin D deficiency in patients undergoing to HSCT. Methods51 patients who underwent HSCT at Albert Einstein Hospital, São Paulo, Brazil, were studied (28 male, 23 female) with a mean age of 50 ± 16 years, in the period from 2012 to 2013. Results54 % had serum levels of vitamin D ≤ 50 nmol/l. And, 12% had serum levels of vitamin D ≤ 25 nmol/l. A multivariate analysis showed that more age and higher Body Mass Index (BMI) were significantly associated to lower serum levels of vitamin D. A negative correlation was found between BMI and serum level of vitamin D (rp=0,37). ConclusionThe use of corticosteroids, immunosuppressive drugs and less lack of sun exposure during the HSCT and during the first year post-HSCT are associated with a greater tendency to deficiency of vitamin D. This deficiency can cause muscle and bone diseases, which can be prevented with diagnosis and early treatment. The deficiency of vitamin D should be carefully investigated in the elderly and obese patients. Disclosures:No relevant conflicts of interest to declare.

Behavior of vitamin E acetate delivery systems under simulated gastrointestinal conditions: Lipid digestion and bioaccessibility of low-energy nanoemulsions

Colloidal delivery systems are needed to incorporate oil-soluble vitamins into aqueous-based foods and beverage products. In this study, we encapsulated vitamin E acetate into oil-in-water nanoemulsions produced using either a low-energy method (Emulsion Phase Inversion, EPI) or a high energy method (microfluidization). Oil-in-water nanoemulsions (d<200nm) could be produced using both low- and high-energy methods from a non-ionic surfactant (Tween 80) and medium chain triglycerides (MCTs). The influence of surfactant-to-oil ratio (SOR) on lipid digestion and vitamin bioaccessibility of EPI nanoemulsions was determined using a gastrointestinal tract (GIT) model that simulated the mouth, stomach, and small intestine. There were increases in the size and negative charge of the oil droplets after passage through the GIT, which was attributed to droplet coalescence and changes in interfacial composition. The rate and extent of lipid digestion decreased with increasing surfactant concentration, but the bioaccessibility of vitamin E acetate was high in all of the samples (>95%). No appreciable influence of the preparation method (low-energy versus high-energy) on lipid digestion and vitamin bioaccessibility was observed. The major advantage of the EPI method for forming nanoemulsions is that no expensive equipment is required, but relatively high surfactant concentrations are needed compared to microfluidization.

Ascorbic acid oxidation in SDS micellar systems

In this contribution the results of atmospheric and electrochemical oxidation of AA in the SDS micellar solutions and in the microemulsions pentanol/water stabilized by SDS are presented. The hydrophilic vitamin C readily dissolves in water and O/W microemulsions as well as undergoes the irreversible two-electron oxidation reaction. It was found that the atmospheric oxidation of AA is accelerated by the SDS up to the CMC and inhibited in the concentrated SDS solutions. We also found that the rate of atmospheric oxidation of ascorbic acid is higher in the water-in-oil (W/O) than in the oil-in-water (O/W) microemulsions and increases with the increasing oil content. The influence of the SDS on the electrochemical behavior of vitamin C was also studied. The general conclusion emerging from this investigation is that the increasing surfactant concentration shifts the ascorbic acid oxidation potential to higher values whereas the corresponding peak current values diminish. In the microemulsions the AA oxidation is slowed down by increasing the pentanol amount in the system.

Voltammetric determination of vitamin E (α-Tocopherol acetate) in multicomponent vitaminized mixtures

The conditions are found for the voltammetric determination of fat-soluble vitamin E (α-tocopherol acetate) in nonaqueous media using carbon electrodes of different types. The electrochemical behavior of vitamin E is studied, and some parameters of the electrode reaction that are of analytical importance are estimated. The stage of sample preparation is optimized by the multifactorial design of experiments. Procedures for determining vitamin E in multicomponent vitaminized mixtures by differential voltammetry are developed and metrologically certified.

Determination of Vitamins E and D3 in Some Preparations by High-Performance Liquid Chromatography with Indirect Spectrophotometric Detection

The behavior of vitamins E and D3 was studied under the conditions of reversed-phase high-performance liquid chromatography with the use of unmodified and modified mobile phases. Acetonitrile modified with chlorophyll (a + b) (Chl) and tetraphenylporfyrin (H2TPP) was selected for the indirect spectrophotometric detection of vitamins. It was demonstrated that detection limits are 2.3 μg (8.33 × 10–6 M H2TPP, λ= 404 nm) and 3.5 ng (8.6 × 10–6 M Chl, λ = 430 nm) for vitamin E and 0.12 μg (3.0 × 10–7 M H2TPP, λ = 420 nm) for vitamin D3 . Pharmaceutical preparations containing vitamins E and D3 were analyzed.

Retention Behavior of Vitamin D N-Acetylglucosaminides During High-Performance Liquid Chromatography

Abstract The retention behavior of N-acetylglucosaminides of vitamin-D2 and -D3, and those of provitamin-D2 and -D3 are examined using reverse phase high performance liquid chromatography. Inclusion chromatography using cyclodextrin as the mobile phase additive is also used for this purpose. The addition of methyl-β-cyclodextrin to the mobile phase is effective in separating the pair of N-acetylglucosaminides of vitamin-D2 and -D3 or those of provitamin-D2 and -D3.

Solvent influence on the kinetics of the photodynamic degradation of trolox, a water-soluble model compound for vitamin E

The kinetics of the aerobic dye-sensitized photo-oxidation of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), a water-soluble model compound for vitamin E, has been studied in aqueous solutions of pH values 6 and 12 and in organic media of different polarity. Experimental evidence indicates that the process largely occurs through a Trolox-singlet molecular oxygen O 2( 1Δ g ) interaction, the photo-oxidation rates increasing with the pH value and the polarity of the medium. Low polarity solvents favour the physical quenching of O 2( 1Δ g ) by Trolox, as already observed in other tocopherols. High polarity solvents drive the interaction predominantly towards a reactive pathway that yields the same substituted p-benzoquinone that can be obtained by thermal oxidation of Trolox. Overall rate constants for the quenching of O 2( 1Δ g ) by Trolox (determined by time-resolved phosphorescence spectroscopy) and reactive rate constants (obtained by relative methods) are both in the range 10 7−10 8 M −1s −1. On the basis of these and their results and their comparison with previous results on the photo-oxidation of tocopherol derivatives, the role of the solvent in the behaviour of vitamin E is discussed.

Behaviour of vitamin e, a and c in patients with documented coronary artery disease

Behaviour of vitamin e, a and c in patients with documented coronary artery disease

Main endocrine modulators of vitamin D hydroxylases in human pathophysiology

Vitamin D is considered to be devoid of direct biological activity. It must be first hydroxylated in the liver by a 25-hydroxylase (250Hase), then in the kidney by a 1 α-hydroxylase (1αOHase) which is responsible for the synthesis of the active metabolite, 1,25-dihydroxyvitamin D (1,25(OH)2D). The activity of 1αOHase is known to be under the control of a series of endocrine modulators, particularly parathyroid hormone (PTH) and estrogens. We report here our studies in humans concerning the behaviour of vitamin D hydroxylases in some pathological conditions. In chronic liver disease no severe impairment of vitamin D-25-hydroxylation has been observed, except in the latest stages: this is probably due to the great functional reserve of the liver, so that normal levels of serum 25OHD can be maintained on condition that the vitamin D supply is adequate. 1αOHase is impaired in chronic renal failure due to the decrease in the number of functioning nephrons. It has been demonstrated that kidney transplantation restores normal 1,25(OH)2D levels. A decrease in 1,25(OH)2D production due to reduced PTH stimulation has been observed in hypoparathyroidism: in these patients a subcutaneous substitution therapy with synthetic human parathyroid hormone resulted in restoration of normal 1,25(OH)2D levels. A reduced activity of 1αOHase due to reduced estrogen stimulation plays a key role in postmenopausal osteoporosis. In these patients estrogens increase 1,25(OH)2D levels, as it has been demonstrated directly and indirectly. In the aforementioned pathological conditions an impairment of calcium absorption has been observed; it was directly related to the reduced production of 1,25(OH)2D. Treatment with 1,25(OH)2D3 was effective in restoring normal calcium absorption. In postmenopausal osteoporosis the reduced levels of 1,25(OH)2D were accompanied by serum levels of 25-hydroxyvitamin D (25OHD) higher than in age-matched control women. In these cases long-term treatment with physiological doses of 1,25(OH)2D3 resulted in a progressive decrease in 25OHD serum levels which approached to the normal range. These finclings are likely to be related one to another: the low 1,25(OH)2D levels are responsible for reduced product-inhibition of 25OHase, so that the synthesis of 25OHD increases. A similar mechanism occurs in renal failure and in hypoparathyroidism.

Polarographic behavior of vitamin K5 in aqueous and alcohol solutions and the application to the determination of vitamin K5 (author's transl)

Polarographic behavior of vitamin K5 in aqueous and alcohol solutions and the application to the determination of vitamin K5 (author's transl)

Reduction of cobalt atom of corrinoid compounds by alkali treatment.

Abstract 1. 1. When cyanocobalamin or 8-aminocobyrinic acid- c -lactam were heated in 30% NaOH at 120° for 1 h, a green substance was formed whose spectrum was similar to that of vitamin B 12s , and this substance readily reacted with emtyyl iodide to yield cobalt-methyl-8-aminocobyrinic acid- c -lactam as the main product. 2. 2. Cyanocobalamin heated anaerobically in 0.4% NaOH at 100° for 10 min gave a yellow-brown substance whose spectrum ws similar to that of vitamine B 12r , and this substance reacted with methyl iodide of n -butyl bromide to yield cobalt-methyl or cobalt- n -butyl derivatives of dehydrocobalamin, respectively, and their mono- to tricarboxylic acid derivatives. 3. 3. On being heated anaerobically in 0.4% NaOH, cyanocobalamin and aquo(or hydroxo)-cobalamin rapidlyturned yellow-brow, while cyanodehydrocobalamin and aquo(or hydroxo)-dehydrocobalamin changed only verly slowly. From these facts it seems probable that the occurrence of the yellow-brown state with the behaviour of vitamin B 12r may be due to the reduction of the cobalt atom accompanied by dehydrogenation on the B ring of the corrin nucleus. 4. 4. The formation of the green substance from 8-aminocobyrinic acid- c -lactam on vigorous alkali treatment is, however, interpreted by assuming another reaction mechanism causing further reduction of the cobalt atom.

Behavior of Vitamin B_1 as a Redox System

Behavior of Vitamin B_1 as a Redox System

COD LIVER OIL

To the Editor:— I have just read the editorials inThe Journal, March 16 and 23, entitled Cod Liver Oil (p. 926) and Variations in Behavior of Vitamin (p. 1008). Each of these articles makes prominent reference to the recent publication from this laboratory, in which a physiologic difference between the vitamin D of cod liver oil and the vitamin D of bluefin tuna liver oil was demonstrated. Unfortunately, there is an error in each of these editorial interpretations, to which attention should be called. The first editorial states that perhaps the most striking support for the peculiar efficacy of cod liver oil has been recently brought forward by Bills, Massengale and Imboden, who found that blue fin tuna liver oil with 40,000 units of vitamin D per gram was only one sixth as effective when assayed with chicks as was cod liver oil with only 100 units of