Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity.
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ABSTRACT:
SUBMITTER: Carazo A
PROVIDER: S-EPMC8157347 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Six types of vitamin K3 (VK3); two sources (menadione sodium bisulfite, MSB; menadione nicotinamide bisulfite, MNB), and three different forms (crystal, micro-capsule, and micro-sphere) were used to determine the retention of VK3 in vitamin premixes (Experiment 1) or vitamin trace mineral (VTM) premixes (Experiment 2) after 1, 2, 3, and 6 months of storage. The retention of VK3 in vitamin premixes was evaluated at 25 °C/60% relative humidity or 40 °C/75% relative humidity in an incubator in Experiment 1 and in VTM premixes (choline chloride: 0 vs. 16,000 mg/kg) stored at room temperature in Experiment 2. The VK3 retention in vitamin premix or VTM premix decreased significantly with the extension of storage time (p < 0.05). In Experiment 1, the VK3 retention was higher in the 25 °C/60% incubator (56%) than in the 40 °C/75% incubator (28%). The MNB retention (52%) was higher than MSB retention (32%). The retention of VK3 in micro-capsules (43%) or micro-spheres (48%) was higher than the crystal form (35%) after six months of storage. In Experiment 2, there was no difference between the retention of MSB (49%) or MNB (47%). The retention of VK3 of micro-capsule (51%) or micro-sphere (54%) was higher than that of crystal form (40%). The VK3 retention was higher in the choline-free group (51%) than in the choline group (47%) after six months of storage. Finally, the predicted equations of VK3 retention with storage time in vitamin premixes or VTM premixes were established. The R2 of the prediction equations was ≥0.9005, indicating that time is an important factor in predicting VK3 retention. In conclusion, the higher temperature-relative humidity, choline had negative effects on VK3 retention during premix storage. MNB retention was higher than MSB during storage of vitamin premix. The encapsulated forms of VK3, micro-capsules and micro-spheres, could improve VK3 storage stability in vitamin premix and VTM premix.
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Project description:Vitamin D testing and the use of vitamin D supplements have increased substantially in recent years. Currently, the role of vitamin D supplementation, and the optimal vitamin D dose and status, is a subject of debate, because large interventional studies have been unable to show a clear benefit (in mostly vitamin D replete populations). This may be attributed to limitations in trial design, as most studies did not meet the basic requirements of a nutrient intervention study, including vitamin D-replete populations, too small sample sizes, and inconsistent intervention methods regarding dose and metabolites. Vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] < 50 nmol/L or 20 ng/ml) is associated with unfavorable skeletal outcomes, including fractures and bone loss. A 25(OH)D level of >50 nmol/L or 20 ng/ml is, therefore, the primary treatment goal, although some data suggest a benefit for a higher threshold. Severe vitamin D deficiency with a 25(OH)D concentration below <30 nmol/L (or 12 ng/ml) dramatically increases the risk of excess mortality, infections, and many other diseases, and should be avoided whenever possible. The data on a benefit for mortality and prevention of infections, at least in severely deficient individuals, appear convincing. Vitamin D is clearly not a panacea, and is most likely efficient only in deficiency. Given its rare side effects and its relatively wide safety margin, it may be an important, inexpensive, and safe adjuvant therapy for many diseases, but future large and well-designed studies should evaluate this further. A worldwide public health intervention that includes vitamin D supplementation in certain risk groups, and systematic vitamin D food fortification to avoid severe vitamin D deficiency, would appear to be important. In this narrative review, the current international literature on vitamin D deficiency, its relevance, and therapeutic options is discussed.
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Project description:Since the early studies of William J. McCormick in the 1950s, vitamin C has been proposed as a candidate for the treatment of cancer. A number of reports have shown that pharmacological concentrations of vitamin C selectively kill cancer cells in vitro and decrease the growth rates of a number of human tumor xenografts in immunodeficient mice. However, up to the date there is still doubt regarding this possible therapeutic role of vitamin C in cancer, mainly because high dose administration in cancer patients has not showed a clear antitumor activity. These apparent controversial findings highlight the fact that we lack information on the interactions that occurs between cancer cells and vitamin C, and if these transformed cells can uptake, metabolize and compartmentalize vitamin C like normal human cells do. The role of SVCTs and GLUTs transporters, which uptake the reduced form and the oxidized form of vitamin C, respectively, has been recently highlighted in the context of cancer showing that the relationship between vitamin C and cancer might be more complex than previously thought. In this review, we analyze the state of art of the effect of vitamin C on cancer cells in vitro and in vivo, and relate it to the capacity of cancer cells in acquiring, metabolize and compartmentalize this nutrient, with its implications on the potential therapeutic role of vitamin C in cancer.
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Project description:As not much is known about the prevalence and predictors of nutritional deficiencies among vegans in the Czech Republic, we evaluated whether supplement use and duration of adherence to the vegan diet are associated with the risk of cobalamin and iron deficiencies. Associations between self-reported supplementation and duration of vegan diet with biomarkers of cobalamin (serum cobalamin, holotranscobalamin, homocysteine, folate) and iron status (serum ferritin, iron binding capacity, transferrin and saturation of transferrin) were assessed by cross-sectional analyses of medical data from a clinical nutrition center. Data from 151 (72 females) adult vegans (age 18-67 years), who were free of major chronic diseases and 85 (40 females) healthy non-vegans (age 21-47 years) were analyzed. Overall, vegans had significantly lower cobalamin, hemoglobin and ferritin levels, but higher folate and MCV values compared to non-vegans. Vegans not using cobalamin supplements were at higher risk of low plasma cobalamin than regularly supplementing vegans (OR: 4.41, 95% CI 1.2-16.16 for cobalamin, OR: 19.18, 95% CI 1.02-359.42 for holotranscobalamin), whereas no significant differences in cobalamin status related to duration of the vegan diet were observed. Regularly supplementing vegans had similar levels of cobalamin/holotranscobalamin as non-vegans. Despite lower ferritin and hemoglobin levels, there was no indication of a higher risk of iron-deficiency among vegans. To conclude cobalamin deficiency risk depends on supplementation status and not on the duration of an exclusive vegan diet, which underlines the need to integrate cobalamin status monitoring and counselling on supplement use in routine clinical care in the Czech Republic.
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Project description:WM164, a human melanoma line, was a gift from Dr M. Herlyn (Wistar Institute, Philadelphia, PA, USA). The cells were cultured using DMEM media supplemented with 10% serum (fetal bovine serum while growing cells and charcoal-treated serum during incubation with vitamin D compounds), 1% antibiotics and 5 g/mL insulin (Sigma-Aldrich, St. Louis, MO, USA). Cells were cultured in 75 cm2 plastic bottles (TPP–Techno Plastic Products AG, Trasadingen, Switzerland) with a filter in an incubator at 37 C with 5% CO2. CRISPR/Cas Knock out of the VDR. The clustered regularly interspaced short palindromic repeats (CRISPR) genetic engineering method was carried out to knock out VDR expression in the WM164 cell line as described in (Cancers 2021, 13, 3111. https://doi.org/10.3390/cancers13133111). The resulting cells with the VDR gene knocked out are designated as WM164 VDR KO, and the cells transduced with an “empty” lentivirus served as a control (WM164 scramble). VDR expression was checked for scramble and VDR KO lines before experiments were performed and further every 4 months after lentivirus treatment to ensure that VDR was not expressed in the WM164 KO. Sources of Vitamin D3 Compounds: Both 1,25(OH)2D3 and 25(OH)D3 were purchased from Sigma. 1,20(OH)2D3 and 20(OH)D3 were chemically synthesized. RNA SEQ: VDR-KO or scramble WM164 cells were plated onto 100 mm2 Petri dishes and treated with 1,25(OH)2D3, 25(OH)D3, 20(OH)D3, 1,20(OH)2D3 or ethanol (control) in triplicates. Cells were incubated in 10% charcoal-treated serum for 24 h. Cells were further harvested and RNA isolated using Absolutly RNA Miniprep Kit (Stratagen) . Approximately 120 ng/ul of each sample was sent for RNAseq analysis. BGI@CHOP genomics company sequenced the samples on Illumina HiSeq TM, analyzed, and sent us the results.
2024-06-01 | GSE248660 | GEO
Project description:The kidney plays an important role in ion homeostasis in the human body. Several hereditary disorders characterized by perturbations in renal magnesium reabsorption leading to hypomagnesemia have been described over the past 50 years, with the most important of these being Gitelman syndrome, familial hypomagnesemia with hypercalciuria and nephrocalcinosis, familial hypomagnesemia with secondary hypocalcemia, autosomal dominant hypomagnesemia with hypocalciuria, and autosomal recessive hypomagnesemia. Only recently, following positional cloning strategies in affected families, have mutations in renal ion channels and transporters been identified in these diseases. In this short review, I give an update on these hypomagnesemic disorders. Elucidation of the genetic etiology and, for most of these disorders, also the underlying pathophysiology of the disease, has greatly increased our understanding of the normal physiology of renal magnesium handling. This is yet another example of the importance of studying rare disorders in order to unravel physiological and pathophysiological processes in the human body.
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Project description:Vitamin D has been proposed as a therapeutic strategy in pancreatic cancer, yet evidence for an effect of dietary vitamin D on pancreatic cancer is ambiguous, with conflicting data from human epidemiological and intervention studies. Here, we tested the role of dietary vitamin D in the in vivo context of the well-characterized Ela1-TAg transgenic mouse model of pancreatic acinar cell carcinoma. Through longitudinal magnetic resonance imaging of mice under conditions of either dietary vitamin D deficiency (<5?IU/kg vitamin D) or excess (76,500?IU/kg vitamin D), compared to control diet (1,500?IU/kg vitamin D), we measured the effect of variation of dietary vitamin D on tumor kinetics. No measurable impact of dietary vitamin D was found on pancreatic acinar cell carcinoma development, growth or mortality, casting further doubt on the already equivocal data supporting potential therapeutic use in humans. The lack of any detectable effect of vitamin D, within the physiological range of dietary deficiency or supplementation, in this model further erodes confidence in vitamin D as an effective antitumor therapeutic in pancreatic acinar cell carcinoma.
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