Characterization of percutaneous absorption of calcium, magnesium, and potentially toxic elements in two tailored sulfurous therapeutic peloids: a comprehensive in vitro pilot study.

Pelotherapy treatments in thermal spas, which utilize peloids composed of clay minerals mixed with saltwater or mineral-medicinal water, can have various effects on spa users, ranging from therapeutic to potential adverse reactions. Despite the widespread use of peloids, comprehensive information on the penetration and permeation of essential and potentially toxic elements into deeper layers of the skin during pelotherapy is limited. Understanding the concentrations of these elements is crucial for evaluating therapeutic benefits and ensuring safety. This study investigates the in vitro availability and absorption of calcium, magnesium, and potentially toxic elements in two peloids, considering their formulation matrix. To replicate the pelotherapy methodology, an in vitro permeation experiment was conducted using a vertical diffusion chamber (Franz cells) and a biological system with human skin membranes from five Caucasian women, age range between 25 and 51 years. The experiment involved heating the peloids to 45℃. The results emphasize the possible transport properties of chemical elements in peloids, providing valuable information related to potential therapeutic efficacy and safety considerations. Despite no apparent differences between peloids' chemical composition, the method identified permeation variations among chemical elements. The methodology employed in this study adheres to the guidelines outlined by OECD for analyzing skin absorption through an in vitro approach. Furthermore, it aligns with the associated OECD guidance document for conducting skin absorption studies. The replicability of this methodology not only facilitates the analysis of peloids pre-formulation but also provides a robust means to evaluate the effectiveness of therapeutic elements during topical administration, particularly those with potential toxicity concerns.

Impact of magnesium supplementation, in combination with vitamin B6, on stress and magnesium status: secondary data from a randomized controlled trial.

Primary findings from a recent study reported that magnesium supplementation significantly reduced stress in severely stressed subjects with low magnesemia, and additional vitamin B6 enhanced this effect. The mechanism by which combining magnesium and vitamin B6 leads to reduced stress in these subjects remains to be elucidated. This secondary analysis investigated the impact of magnesium and vitamin B6 supplementation and perceived stress on erythrocyte magnesium levels, as a marker of body magnesium status. This was a secondary analysis from an 8-week randomized controlled trial comparing oral magnesium (300 mg) and magnesium-vitamin B6 (300 mg + 30 mg) supplementation. Stress level and erythrocyte magnesium level at baseline, and change in erythrocyte magnesium and serum vitamin B6 levels at weeks 4 and 8, were analyzed. Overall, 264 subjects were randomized to treatment and had evaluable Depression Anxiety Stress Scale scores (132 in each treatment arm). At baseline, stress scores, and mean serum magnesium, erythrocyte magnesium, and serum vitamin B6 concentrations were similar between arms. Although not significant between groups, a significant increase over time in erythrocyte magnesium levels was observed in the subgroup of subjects with low baseline erythrocyte magnesium levels (<1.6 mmol/L) following treatment with magnesium and magnesium-vitamin B6 (week 4:0.21 mmol/L [95% confidence interval (CI), 0.10 to 0.31], p = 0.0003; and 0.13 mmol/L [95% CI, 0.02 to 0.23], p = 0.0233, respectively). Change from baseline in circulating vitamin B6 levels at weeks 4 and 8 in the magnesium-vitamin B6 supplemented group (314.96 nmol/L [95%CI, 294.61 to 335.31]) was significantly different (p < 0.0001) compared with the magnesium supplemented group (-0.39 nmol/L [95% CI, -20.73 to 19.94]). Magnesium alone and magnesium-vitamin B6 provided statistically significant increases in erythrocyte magnesium in subjects with low magnesium status (<1.6mmol/L). Vitamin B6 supplementation did not further increase magnesium levels.

Headaches and Magnesium: Mechanisms, Bioavailability, Therapeutic Efficacy and Potential Advantage of Magnesium Pidolate.

Magnesium deficiency may occur for several reasons, such as inadequate intake or increased gastrointestinal or renal loss. A large body of literature suggests a relationship between magnesium deficiency and mild and moderate tension-type headaches and migraines. A number of double-blind randomized placebo-controlled trials have shown that magnesium is efficacious in relieving headaches and have led to the recommendation of oral magnesium for headache relief in several national and international guidelines. Among several magnesium salts available to treat magnesium deficiency, magnesium pidolate may have high bioavailability and good penetration at the intracellular level. Here, we discuss the cellular and molecular effects of magnesium deficiency in the brain and the clinical evidence supporting the use of magnesium for the treatment of headaches and migraines.

The Coordination Chemistry of Bio-Relevant Ligands and Their Magnesium Complexes.

The coordination chemistry of magnesium (Mg2+) was extensively explored. More recently; magnesium; which plays a role in over 80% of metabolic functions and governs over 350 enzymatic processes; is becoming increasingly linked to chronic disease-predominantly due to magnesium deficiency (hypomagnesemia). Supplemental dietary magnesium utilizing biorelevant chelate ligands is a proven method for counteracting hypomagnesemia. However, the coordination chemistry of such bio-relevant magnesium complexes is yet to be extensively explored or elucidated. It is the aim of this review to comprehensively describe what is currently known about common bio-relevant magnesium complexes from the perspective of coordination chemistry.

Magnesium oil enriched transdermal nanogel of methotrexate for improved arthritic joint mobility, repair, and reduced inflammation.

Aim: Methotrexate (Mtx) is prescribed to reduce pain and inflammation in arthritis patients; however, improved repair and mobility of joints still are the major concerns. Magnesium oil (MO) improves joint mobility and repair; therefore, MO-assisted transdermal delivery of Mtx was aimed.Methods: MO integrated Mtx nanoemulsion (Mtx-MONE) was prepared with uniform size (175 ± 35.4 nm), pH (6.15 ± 0.3) near to skin pH, and high entrapment efficiency (65 ± 8.6%). Mtx-MONE was transformed to nanogel (Mtx-MONEG) with semisolid consistency (43,408 ± 77.72 cP) and good spreadability (3.63 ± 0.033 mJ).Results: Mtx-MONEG showed significant reduction in oedema, arthritic scores, level of inflammatory cytokines, and improved walking as compared to diseased control. MO offered additional improvements in joints, mobility, and repair.Conclusion: Transdermal delivery of Mtx has been successfully achieved by Mtx-MONEG. Tremendous recovery from inflammation, improved joints mobility and repair, and reduced pain strongly support the use of MO as an adjutant of Mtx for improved transdermal application.

Magnesium Bioavailability and Tolerability Do Not Differ between Two Supplements with Different Release Properties.

Magnesium (Mg2+) is one of the most frequently supplemented micronutrients. Due to possible gastrointestinal side effects, the European Food Safety Authority and the Institute of Medicine set the upper intake level for Mg2+ from supplements to 250 and 350 mg, respectively. Nevertheless, systematic data concerning the tolerability of Mg2+ supplements are scarce. The aim of the study was to directly compare the bioavailability and tolerability of two 500 mg Mg2+ supplements in a crossover study with duplicate determination. The different release properties were either a direct release (one phase) or a delayed release of the second half (two phases). An open-label, controlled trial with a crossover design, duplicate determination, and one-week washout phases was conducted. The participants ingested the test product after overnight fasting. Blood samples were taken at baseline and after 1, 2, 3, 4, 6, and 8 hours, and urine was collected over a period of 24 hours. The participants were on standardized nutrition during all examination days. There were no significant differences between the test products regarding 24-hour renal Mg2+ excretion and area under the curve of serum Mg2+ levels for 8 hours. Both test products were well tolerated with a very low frequency of gastrointestinal adverse effects and no significant differences between the test products. The Mg2+ bioavailability did not differ between the test products. The supplements examined had the same good tolerability. Both test products are therefore suited to enhance Mg2+ supply without relevant side effects.

Antimicrobial Properties of Magnesium Open Opportunities to Develop Healthier Food.

Magnesium is a vital mineral that takes part in hundreds of enzymatic reactions in the human body. In the past several years, new information emerged in regard to the antibacterial effect of magnesium. Here we elaborate on the recent knowledge of its antibacterial effect with emphasis on its ability to impair bacterial adherence and formation complex community of bacterial cells called biofilm. We further talk about its ability to impair biofilm formation in milk that provides opportunity for developing safer and qualitative dairy products. Finally, we describe the pronounced advantages of enrichment of food with magnesium ions, which result in healthier and more efficient food products.

Predicting and Testing Bioavailability of Magnesium Supplements.

Despite the presumption of the beneficial effects of magnesium supplementation, little is known about the pharmacokinetics of different magnesium formulations. We aimed to investigate the value of two in vitro approaches to predict bioavailability of magnesium and to validate this in subsequent in vivo testing. In vitro assessment of 15 commercially available magnesium formulations was performed by means of a Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) and by dissolution tests. Two magnesium formulations with contrasting bioavailability prediction from both in vitro tests (best vs. worst) were selected for in vivo testing in 30 subjects. In vivo bioavailability was compared following one acute ingestion by monitoring blood magnesium concentrations up to 6 h following intake. The in vitro tests showed a very wide variation in absorption and dissolution of the 15 magnesium products. In the in vivo testing, a significant different serum magnesium absorption profile was found up to 4 h following supplement ingestion for the two supplements with opposing in vitro test results. Moreover, maximal serum magnesium increase and total area under the curve were significantly different for both supplements (+6.2% vs. +4.6% and 6.87 vs. 0.31 mM.min, respectively). Collectively, poor bioaccessibility and bioavailability in the SHIME model clearly translated into poor dissolution and poor bioavailability in vivo. This provides a valid methodology for the prediction of in vivo bioavailability and effectiveness of micronutrients by specific in vitro approaches.

Assessment of bioavailability of Mg from Mg citrate and Mg oxide by measuring urinary excretion in Mg-saturated subjects.

BACKGROUND: Low magnesium (Mg) levels are linked to many diseases. Studies suggest that organic salts of Mg are more readily bioavailable than its oxide or inorganic salts used for supplements production. Unfortunately, the plethora of variables in the previous study designs complicates the making of any clear and reliable conclusions. METHODS: 14 healthy males were supplemented for five days with 400 mg Mg to saturate Mg pools before intake of the test products. Bioavailability of 400 mg Mg from Mg citrate (MgC) and Mg oxide (MgO) after single-dose administration was assessed by measuring renal Mg excretion in 24-h urine and blood plasma [Mg] at time points 0, 2, 4, 8, and 24 h. RESULTS: Single-dose MgC supplementation led to a significant (P < 0.05) increase in 24 h urinary Mg excretion, but this was not significant following MgO. Plasma [Mg] was also significantly higher for MgC than for MgO at 4 h (P < 0.05) and 8 h (P < 0.05). Compared with baseline levels, MgC supplementation showed a significant increase in plasma [Mg] at all time points, in contrast to MgO. CONCLUSIONS: MgC shows higher bioavailability compared with MgO. Furthermore, urinary Mg excretion should be determined as the primary endpoint of Mg bioavailability studies.

The absolute bioavailability and the effect of food on a new magnesium lactate dihydrate extended-release caplet in healthy subjects.

OBJECTIVE: To assess the absolute bioavailability of 20 mEq magnesium lactate extended-release (ER) caplets and to assess the effect of food on the pharmacokinetics of these ER caplets. SIGNIFICANCE: Magnesium in different salt forms is available as over-the-counter oral formulations. The absorption and bioavailability is highly affected by the water solubility of the salt form. A new ER caplet of 10 mEq strength of magnesium L-lactate dihydrate has been developed to increase the bioavailability of magnesium. METHODS: An open label, single-dose, randomized, three-period, cross-over study in healthy adults was conducted with three treatments: (a) single oral dose of 20 mEq magnesium L-lactate dehydrate under fasting conditions, (b) single intravenous (IV) infusion of 20 mEq magnesium sulfate, and (c) single oral dose of 20 mEq magnesium L-lactate dehydrate under fed conditions. Urine and blood samples were collected for analysis of urinary and serum magnesium concentrations. RESULTS: Absolute bioavailabilities of the caplets under fasted and fed conditions, compared to IV magnesium sulfate, were 20.26% (fasted) and 12.49% (fed) in serum, based on the geometric mean ratio (GMR) of the baseline-adjusted AUC0-72, and 38.11% (fasted) and 40.99% (fed) in urine, based on the GMR of the baseline-adjusted Ae0-72. Relative bioavailability of the caplets comparing the fed and fasted states was 61.67% in serum, based on the GMR of the baseline-adjusted AUC0-72, and 107.57% in urine, based on the GMR of the baseline-adjusted Ae0-72. CONCLUSIONS: This new magnesium formulation has reasonable bioavailability and might be a valuable addition to the currently available magnesium oral products.

An Advanced Formulation of a Magnesium Dietary Supplement Adapted for a Long-Term Use Supplementation Improves Magnesium Bioavailability: In Vitro and Clinical Comparative Studies.

While general recommendations are for 300-mg magnesium intake a day, an advanced low-dose formulation of magnesium chloride, ChronoMag®, was designed to provide 100 mg of magnesium element, thus decreasing the risk of gastrointestinal side effects and allowing long-term supplementation in health conditions related to low magnesium levels. The present study aimed to compare magnesium release profile and bioavailability between this patented low-dose continuous-release magnesium chloride tablet (100 mg magnesium element) and a reference tablet at the usually prescribed dose (300 mg magnesium element). Magnesium release profile was determined by dissolving the tablets in solutions simulating the gastrointestinal tract environment. A randomized double-blind crossover controlled trial of ChronoMag® versus reference tablet (3 × 100 mg magnesium element tablets) in 12 normo-magnesemic healthy volunteers was conducted to evaluate the bioavailability of the patented magnesium chloride tablets (two 50 mg magnesium tablets, once-a-day intake). While the reference tablet released 100% of its magnesium within 1 h of dissolution, release from the magnesium chloride formulation was continuous for 6 h. Cumulative urinary magnesium levels compared to those with the reference tablet were 76% (0-5 h), 89% (0-10 h), and 87% (0-24 h). Elimination after 24 h was fairly similar with both supplements. Our results suggest that the new magnesium chloride formulation, providing continuous low-dose magnesium release throughout the gastrointestinal tract, improves absorption and bioavailability. This formulation conforms to the physiological mechanism of magnesium absorption throughout the digestive tract, allowing high absorption, and may improve gastrointestinal tolerance in long-term use.

Scottsdale Magnesium Study: Absorption, Cellular Uptake, and Clinical Effectiveness of a Timed-Release Magnesium Supplement in a Standard Adult Clinical Population.

OBJECTIVE: Suboptimal magnesium status is likely widespread in the United States and increasing evidence links it to many chronic diseases. Therapeutically addressing magnesium status can be challenging, as higher supplementation often leads to bowel intolerance. This study evaluated the absorption, cellular uptake, and clinical effectiveness of a timed-release formulation containing dimagnesium malate with vitamins B6, B12, and folate (MagSRT™) in a standard clinical population. METHODS: A standard clinical population of 91 adults participated in a placebo-controlled study carried out at two clinics; 53 individuals received MagSRT™, containing 500 mg dimagnesium malate and vitamins B6, B12, and folate, while the remaining individuals received a placebo. Baseline serum magnesium, red blood cell (RBC) magnesium, and magnesium status questionnaire scores were collected prior to trial initiation. Serum magnesium was measured 4 and 8 hours after participants ingested 2 supplemental tablets (250 mg magnesium) or 2 placebo tablets. After 30 days, RBC magnesium was evaluated and participants completed the magnesium status questionnaire. A subset of MagSRT™ participants (24) continued the trial for 90 days. Both RBC magnesium and the magnesium status questionnaire were evaluated at 90 days. RESULTS: More than 75% of trial participants presented with suboptimal serum and RBC magnesium status at baseline, while the magnesium status questionnaire predicted 100% of participants to have suboptimal magnesium status. MagSRT™ was well tolerated by 91% of magnesium intervention participants. RBC magnesium increased 6% and 30% over 30 and 90 days, respectively, suggesting magnesium absorption and uptake into red blood cells over time. Overall symptomatology, assessed through a magnesium status questionnaire, improved 28% over 30 days and 63% over 90 days. CONCLUSION: A standard adult clinical population presented with both qualitative and quantitative evidence of compromised magnesium status at the beginning of the trial. Supplementation with MagSRT™, a timed-release dimagnesium malate supplement containing vitamins B6, B12, and folate, for at least 30 days significantly improved magnesium status symptoms and increased RBC magnesium with minimal gastrointestinal symptoms.

Magnesium in Breast Cancer: What Is Its Influence on the Progression of This Disease?

Breast cancer is a disease of high mortality, characterized by the progressive accumulation of mutations that contribute to the uncontrolled development of breast tissue cells. Literature shows that disturbances in mineral homeostasis, such as magnesium, may interfere with tumor progression. The objective of this study is to provide updated information about magnesium's role in the pathogenesis of breast cancer. A review of literature was carried out from a search for articles in the PubMed and CAPES Periodicals databases published between 1995 and 2016 with the cross-references of the descriptors "magnesium," "breast neoplasms," and "oxidative stress" and the corresponding words in Portuguese. We included studies on the metabolism and bioavailability of magnesium and studies related to breast cancer and excluded articles in which only the abstract was available, dissertations, theses, articles involving adjuvant and/or neoadjuvant therapies, and supplementation of minerals in breast cancer patients. Magnesium is a mineral that participates in the metabolism of various nutrients and nucleic acids. In the presence of breast cancer, neoplastic cells increase the expression of magnesium transport channels, which raises the intracellular concentration of the mineral, contributing to tumor growth through its function of increasing energy demand. The data obtained in this review illustrates the influence of magnesium on the progression of breast cancer. However, the existing data are scarce and inconsistent, which demonstrates a need for further studies on the subject with a goal to have better control of the disease.

The role of magnesium and zinc in depression: similarities and differences.

Antidepressant therapy exhibits low clinical efficacy and produces a variety of unwanted side effects. Therefore, the search for more effective antidepressants is still in progress. Antidepressant properties of magnesium and zinc have been demonstrated in animal screen tests/models and clinical studies. Moreover, these bio-elements enhance antidepressant activity of conventional antidepressants in these behavioral paradigms. As for magnesium, clinical studies demonstrated equivocal results concerning its supplementary effectiveness in the treatment of depression. Generally, some depressed patients with hypomagnesemia responded very well to such supplementation, whereas response of other patients was weaker. Clinical data on the effectiveness of zinc supplementation in the therapy of depression are much more robust. A number of studies demonstrated enhancement of the efficacy of pharmacotherapy by zinc supplementation in major depression. What is important, recent studies demonstrate that zinc supplementation augments efficacy of antidepressants also in treatment-resistant patients. All the available data indicate the importance of magnesium and zinc in the therapy of depression.

In Vitro Bioavailability of Calcium, Magnesium, Iron, Zinc, and Copper from Gluten-Free Breads Supplemented with Natural Additives.

The aim of this study was to measure the content of calcium, magnesium, iron, zinc, and copper and determine the bioavailability of these ingredients in gluten-free breads fortified with milk and selected seeds. Due to the increasing prevalence of celiac disease and mineral deficiencies, it has become necessary to produce food with higher nutritional values which maintains the appropriate product characteristics. This study was designed for gluten-free breads fortified with milk and seeds such as flax, poppy, sunflower seeds, pumpkin seeds or nuts, and flour with amaranth. Subsequently, digestion was performed in vitro and the potential bioavailability of the minerals was measured. In the case of calcium, magnesium, iron, and copper, higher bioavailability was observed in rice bread, and, in the case of copper and zinc, in buckwheat bread. This demonstrated a clear increase in bioavailability of all the minerals when the bread were enriched. However, satisfactory results are obtained only for the individual micronutrients.

Effect of transdermal magnesium cream on serum and urinary magnesium levels in humans: A pilot study.

BACKGROUND: Oral magnesium supplementation is commonly used to support a low magnesium diet. This investigation set out to determine whether magnesium in a cream could be absorbed transdermally in humans to improve magnesium status. METHODS AND FINDINGS: In this single blind, parallel designed pilot study, n = 25 participants (aged 34.3+/-14.8y, height 171.5+/-11cm, weight 75.9 +/-14 Kg) were randomly assigned to either a 56mg/day magnesium cream or placebo cream group for two weeks. Magnesium serum and 24hour urinary excretion were measured at baseline and at 14 days intervention. Food diaries were recorded for 8 days during this period. Mg test and placebo groups' serum and urinary Mg did not differ at baseline. After the Mg2+ cream intervention there was a clinically relevant increase in serum magnesium (0.82 to 0.89 mmol/l,p = 0.29) that was not seen in the placebo group (0.77 to 0.79 mmol/L), but was only statistically significant (p = 0.02)) in a subgroup of non-athletes. Magnesium urinary excretion increased from baseline slightly in the Mg2+ group but with no statistical significance (p = 0.48). The Mg2+ group showed an 8.54% increase in serum Mg2+ and a 9.1% increase in urinary Mg2+ while these figures for the placebo group were smaller, i.e. +2.6% for serum Mg2+ and -32% for urinary Mg2+. In the placebo group, both serum and urine concentrations showed no statistically significant change after the application of the placebo cream. CONCLUSION: No previous studies have looked at transdermal absorbency of Mg2+ in human subjects. In this pilot study, transdermal delivery of 56 mg Mg/day (a low dose compared with commercial transdermal Mg2+ products available) showed a larger percentage rise in both serum and urinary markers from pre to post intervention compared with subjects using the placebo cream, but statistical significance was achieved only for serum Mg2+ in a subgroup of non-athletes. Future studies should look at higher dosage of magnesium cream for longer durations. TRIAL REGISTRATION: ISRCTN registry ID No. ISRTN15136969.

Magnesium Status and Its Association with Oxidative Stress in Obese Women.

The aim of this study was to assess the relationship between magnesium status and oxidative stress in obese and nonobese women. This cross-sectional study included 83 women, aged between 20 and 50 years, who were divided into two groups: the obese group (n = 31) and the control group (n = 52). The control group was age-matched with the obese group. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma and erythrocyte magnesium concentrations were determined by flame atomic absorption spectrophotometry. Plasma levels of thiobarbituric acid reactive substances (TBARS) were determined as biomarkers for lipid peroxidation and therefore of oxidative stress. The mean values of the magnesium content in the diet were found to be lower than those recommended, though there was no significant difference between groups (p > 0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p > 0.05). The mean concentration of plasma TBARS was higher in obese woman, and the difference between the groups was statistically different (p < 0.05). There was a positive correlation between erythrocyte magnesium and plasma TBARS in the obese group (p = 0.021). Obese patients ingest low dietary magnesium content, which does not seem to affect the plasma and erythrocyte concentrations of the mineral. The study showed a negative correlation between erythrocyte magnesium concentrations and plasma TBARS, suggesting the influence of magnesium status on the parameters of oxidative stress in obese women.

Homeostasis of chosen bioelements in organs of rats receiving lithium and/or selenium.

Lithium is an essential trace element, widely used in medicine and its application is often long-term. Despite beneficial effects, its administration can lead to severe side effects including hyperparathyroidism, renal and thyroid disorders. The aim of the current study was to evaluate the influence of lithium and/or selenium treatment on magnesium, calcium and silicon levels in rats' organs as well as the possibility of using selenium as an adjuvant in lithium therapy. The study was performed on rats divided into four groups (six animals each): control-treated with saline; Li-treated with Li2CO3 (2.7 mg Li/kg b.w.); Se-treated with Na2SeO3·H2O (0.5 mg Se/kg b.w.); Se + Li-treated simultaneously with Li2CO3 and Na2SeO3·H2O (2.7 mg Li/kg b.w. and of 0.5 mg Se/kg b.w., respectively). The administration was performed in form of water solutions by stomach tube once a day for 3 weeks. In the organs (liver, kidney, brain, spleen, heart, lung and femoral muscle) the concentrations of magnesium, calcium and silicon were determined. Magnesium was increased in liver of Se and Se + Li given rats. Lithium decreased tissue Ca and co-administration of selenium reversed this effect. Silicon was not affected by any treatment. The beneficial effect of selenium on disturbances of calcium homeostasis let suggest that further research on selenium application as an adjuvant in lithium therapy is worth being performed.

The acute effect of high-dose intravenous vitamin C and other nutrients on blood pressure: a cohort study.

BACKGROUND: Regular intake of vitamin C/ascorbate reduces blood pressure (BP) in hypertensives. High-dose intravenous vitamin C (IVC) achieves higher plasma levels; however, there is a paucity of research on acute BP effects. Our study is the first to investigate the effect of high-dose IVC, with or without concomitant i.v. nutrients, on BP during i.v. METHODS: A cohort of adult patients scheduled to receive IVC treatment for infection, cancer or fatigue, as prescribed by their treating doctor, participated at a Melbourne clinic, Australia. Ambulatory BP was assessed every 10 min over 90 min during i.v. TREATMENT: Patients received 15-100 g of IVC alone or in addition to i.v. vitamin B, glutathione, magnesium or zinc. BP change over time adjusted for baseline BP, IVC dosage, i.v. treatment and BMI was analysed. RESULTS: A total of 77 mostly normotensive patients participated, with a third receiving IVC alone (42±20 g), and two-thirds also received other i.v. nutrients. IVC alone (>30 g) reduced the mean BP up to 8-9 mmHg in prehypertensive patients. In contrast, concomitant intravenous vitamin B12 (IVB12) significantly increased the mean BP by 11-13 mmHg. Comparison of BP change during IVC versus IVC+IVB12 indicated a highly significant difference [systolic blood pressure: mean difference (SD)=16.6 (17.8) mmHg, P<0.001; diastolic blood pressure: mean difference (SD)=12.5 (16.7) mmHg, P=0.003]. CONCLUSION: Our study suggests an acute BP-reducing effect of high-dose IVC, particularly with dosages above 30 g, and in patients with prehypertension and normal BMI. Furthermore, our study indicated a marked and clinically relevant hypertensive effect of IVB12, suggesting routine BP monitoring during i.v. therapy in clinical practice.

Dietary mannitol increased the absorption of calcium and magnesium in rats.

The effect of mannitol on bone-related mineral absorption and retention and the mechanism was investigated in this study. Fourteen 8-week-old male Wistar rats in experiment 1 and same number and age cecectomized Wistar male rats in experiment 2 were divided into two subgroups of seven animals, respectively, fed diets containing 0 or 4% mannitol for 28 days. Mineral balance tests were determined twice during days 8-12 and days 22-26, and the rats were slaughtered on day 28 both in experiment 1 and experiment 2. The whole caecum and colon were collected with the content to analyse tissue weight, content weight, content's pH and moisture, organic acids' concentration and mineral levels. In experiment 1, Ca absorption and retention and Mg absorption were significantly increased by mannitol feeding during days 8-12. Caecal total weight, tissue weight and content weight were increased, the pH of caecum and colon was reduced, and the concentrations of caecal short-chain fatty acids (SCFAs) were modified by mannitol feeding. In experiment 2, during days 8-12 and days 22-26, Ca absorption and retention were significantly lowered by mannitol feeding in cecectomized rats; however, mannitol feeding decreased Mg absorption during days 8-12, but did not impact Mg retention. Colonic total weight, tissue weight and content weight were significantly increased, and colonic pH was reduced by mannitol feeding. In conclusion, dietary mannitol increased the absorption of Ca and Mg and the caecum markedly contributed to this promoting effect of mannitol.