Acute ascorbic acid ingestion increases skeletal muscle blood flow and oxygen consumption via local vasodilation during graded handgrip exercise in older adults

High blood pressure (hypertension)

Summary Human aging is associated with reduced skeletal muscle perfusion during exercise, which may be a result of impaired endothelium-dependent dilation and/or attenuated ability to blunt sympathetically mediated vasoconstriction. Intra-arterial infusion of ascorbic acid (AA) increases nitric oxide-mediated vasodilation and forearm blood flow (FBF) during handgrip exercise in older adults, yet it remains unknown whether…

Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism

High blood pressure (hypertension)

Summary The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip…

Vitamin C improves endothelium-dependent vasodilation by restoring nitric oxide activity in essential hypertension

High blood pressure (hypertension)

Summary Background: Essential hypertension is associated with impaired endothelium-dependent vasodilation. Inactivation of endothelium-derived nitric oxide by oxygen free radicals participates in endothelial dysfunction in experimental hypertension. To test this hypothesis in humans, we evaluated the effect of antioxidant vitamin C on endothelium-dependent responses in essential hypertensive patients. Methods and results: In 14 healthy subjects (47.1+/-4.8…

L-ascorbic acid potentiates endothelial nitric oxide synthesis via a chemical stabilization of tetrahydrobiopterin

High blood pressure (hypertension)

Summary Ascorbic acid has been shown to stimulate endothelial nitric oxide (NO) synthesis in a time- and concentration-dependent fashion without affecting NO synthase (NOS) expression or l-arginine uptake. The present study investigates if the underlying mechanism is related to the NOS cofactor tetrahydrobiopterin. Pretreatment of human umbilical vein endothelial cells with ascorbate (1 microm to…

Ascorbic acid enhances endothelial nitric-oxide synthase activity by increasing intracellular tetrahydrobiopterin

High blood pressure (hypertension)

Summary Ascorbic acid enhances NO bioactivity in patients with vascular disease through unclear mechanism(s). We investigated the role of intracellular ascorbic acid in endothelium-derived NO bioactivity. Incubation of porcine aortic endothelial cells (PAECs) with ascorbic acid produced time- and dose-dependent intracellular ascorbic acid accumulation that enhanced NO bioactivity by 70% measured as A23187-induced cGMP accumulation.…

Ascorbic Acid Protects against Hypertension through Downregulation of ACE1 Gene Expression Mediated by Histone Deacetylation in Prenatal Inflammation-Induced Offspring

High blood pressure (hypertension)

Summary Hypertension is a major risk factor for cardiovascular and cerebrovascular disease. Prenatal exposure to lipopolysaccharide (LPS) leads to hypertension in a rat offspring. However, the mechanism is still unclear. This study unraveled epigenetic mechanism for this and explored the protective effects of ascorbic acid against hypertension on prenatal inflammation-induced offspring. Prenatal LPS exposure resulted…

Vitamin C Lowers Blood Pressure in Spontaneously Hypertensive Rats by Targeting Angiotensin-Converting Enzyme I Production in a Frequency-Dependent Manner

High blood pressure (hypertension)

Summary The lowering blood pressure effect of vitamin C (VC) has been evaluated in various models. As VC has a fast degradation rate in the body after consumption, a study of the frequency-dependent manner of VC is essential for the sustained antihypertension effect of VC. In this study, we investigated the frequency and dose dependency…

Ascorbic acid decreases the binding affinity of the AT1 receptor for angiotensin II

High blood pressure (hypertension)

Summary Background: Ascorbic acid is an essential vitamin and a powerful antioxidant. Many studies have highlighted the benefits of ascorbic acid for chronic cardiovascular diseases such as hypertension in which angiotensin II (Ang II) plays an significant role. We therefore hypothesized that ascorbic acid could modify the pharmacological properties of the AT(1) receptor for Ang…

Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials

High blood pressure (hypertension)

Summary Background: In observational studies, increased vitamin C intake, vitamin C supplementation, and higher blood concentrations of vitamin C are associated with lower blood pressure (BP). However, evidence for blood pressure-lowering effects of vitamin C in clinical trials is inconsistent. Objective: The objective was to conduct a systematic review and meta-analysis of clinical trials that…

Vitamin C supplementation improves blood pressure and oxidative stress after acute exercise in patients with poorly controlled type 2 diabetes mellitus: A randomized, placebo-controlled, cross-over study

High blood pressure (hypertension)

Summary This study aimed to assess the effect of Vitamin C on blood pressure (BP), and subsequently on oxidative stress and nitric oxide (NO) release, following the low-intensity exercise in the patients. This study included 24 patients with type 2 diabetes mellitus (T2D) (age, 53 ± 7 years; hemoglobin A1c, 10.1% ± 0.9%) randomized into…

Vitamin C Deficiency-Induced Pulmonary Arterial Hypertension

High blood pressure (hypertension)

Summary We report a case of a man in his 60s who developed pulmonary arterial hypertension (PAH) in association with profound vitamin C deficiency. Decreased availability of endothelial nitric oxide and activation of the hypoxia-inducible family of transcription factors, both consequences of vitamin C deficiency, are believed to be mechanisms contributing to the pathogenesis of…

Effect of ascorbic acid on endothelial dysfunction of epicardial coronary arteries in chronic smokers assessed by cold pressor testing

High blood pressure (hypertension)

Summary Background: In chronic smokers there is evidence for increased formation of oxygen-derived free radicals within the vessel wall impairing endothelial function. It has been suggested that the inactivation of endothelium-derived nitric oxide by oxygen free radicals contributes to endothelial dysfunction. Hence, we tested the hypothesis that in chronic smokers the antioxidant ascorbic acid could…

Supplementation with vitamins C and E improves arterial stiffness and endothelial function in essential hypertensive patients.

High blood pressure (hypertension)

Summary Background: Essential hypertension is characterized by endothelial dysfunction, arterial stiffness, and increased oxidative stress. We evaluated the effect of short-term combined treatment with the antioxidants vitamins C and E on endothelial function, arterial stiffness, and oxidative stress in untreated essential hypertensive patients. Methods: A randomized, double-blind, placebo-controlled, crossover study design was used to assign…

Effects of ascorbic acid on ambulatory blood pressure in elderly patients with refractory hypertension

High blood pressure (hypertension)

Summary The increased production of reactive oxygen species plays a role in the etiology of hypertension, but the effects of antioxidants on blood pressure are controversial. However, antioxidants possibly lower blood pressure in elderly patients with hypertension, because vascular aging is also closely related to oxidative stress. Effects of chronic treatment with ascorbic acid (CAS…

Authors’ perspective: What is the optimum intake of vitamin C in humans?

High blood pressure (hypertension)

Summary The recommended dietary allowance (RDA) of vitamin C has traditionally been based on the prevention of the vitamin C deficiency disease, scurvy. While higher intakes of vitamin C may exert additional health benefits, the limited Phase III randomized placebo-controlled trials (RCTs) of vitamin C supplementation have not found consistent benefit with respect to chronic…

Effect of acute administration of vitamin C on muscle sympathetic activity, cardiac sympathovagal balance, and baroreflex sensitivity in hypertensive patients

High blood pressure (hypertension)

Summary Background: Essential hypertension is characterized by both increased oxidative stress and sympathetic traffic. Experimental studies have shown that reactive oxygen species can modulate autonomic activity. Objective: The aim of this study was to determine whether acute administration of the antioxidant vitamin C modifies sympathetic nerve activity in essential hypertension. Design: Thirty-two untreated patients with…

Effects of vitamin C supplementation on essential hypertension: A systematic review and meta-analysis

High blood pressure (hypertension)

Summary Background: Vitamin C as a supplement to treat hypertension has been proposed. However, it remains controversial whether vitamin C can improve blood pressure in patients with primary hypertension. Objectives: To analyze the effect of vitamin C (VitC) supplementation on systolic (SBP) and diastolic (DBP) blood pressure in patients with essential hypertension. Methods: We searched…

Vitamin C improves endothelial function of epicardial coronary arteries in patients with hypercholesterolaemia or essential hypertension–assessed by cold pressor testing

High blood pressure (hypertension)

Summary Aims: There is evidence that formation of free radicals increases in patients with hypertension or hypercholesterolaemia, which may contribute to endothelial dysfunction of epicardial coronary arteries due to inactivation of the vasodilator NO. The present study was designed to test whether the abnormal constriction of epicardial coronary arteries due to sympathetic stimulation by the…

Serum vitamin C concentration was inversely associated with subsequent 20-year incidence of stroke in a Japanese rural community. The Shibata study

High blood pressure (hypertension)

Summary Background and purpose: Epidemiological evidence suggests that vitamin C may decrease the risk of stroke. The purpose of the present study was to examine the association of serum vitamin C concentration with the subsequent incidence of stroke. Methods: In a Japanese rural community, a cohort of 880 men and 1241 women aged 40 years…

High-Dose Vitamin C Prevents Secondary Brain Damage After Stroke via Epigenetic Reprogramming of Neuroprotective Genes

High blood pressure (hypertension)

Summary Vitamin C has recently been identified as an epigenetic regulator by activating ten-eleven translocases (TETs), enzymes involved in generating DNA hydroxymethylcytosine (5hmC). Currently, we investigated whether high-dose vitamin C promotes neuroprotection through epigenetic modulation of 5hmC, if there are sex-specific differences in outcome, and the therapeutic potential of vitamin C in stroke-related comorbidities in…

Ascorbate Attenuates Oxidative Stress and Increased Blood Pressure Induced by 2-(4-Hydroxyphenyl) Amino-1,4-naphthoquinone in Rats

High blood pressure (hypertension)

Summary Quinone derivatives like 2-(4-hydroxyphenyl) amino-1,4-naphthoquinone (Q7) are used as antitumor agents usually associated with adverse effects on the cardiovascular system. The objective of this study was to evaluate the cardioprotective effect of ascorbate on Q7-induced cardiovascular response in Wistar rats. In this study, blood pressure, vascular reactivity, and intracellular calcium fluxes were evaluated in…

Ascorbic acid supplementation improves postprandial glycaemic control and blood pressure in individuals with type 2 diabetes: Findings of a randomized cross-over trial

High blood pressure (hypertension)

Summary Aim: The primary aim of this study was to investigate whether ascorbic acid (AA) supplementation improves postprandial glucose responses under free-living conditions in individuals with type 2 diabetes. A secondary aim was to investigate the effect of AA supplementation on blood pressure. Materials and methods: A total of 31 individuals with type 2 diabetes…

Decrease in oxidative stress through supplementation of vitamins C and E is associated with a reduction in blood pressure in patients with essential hypertension

High blood pressure (hypertension)

Summary Plant-derived bioflavonoids have been recognized to support arterial wall structural integrity and interfere with a variety of pro-atherosclerotic stimuli. This study examined the effect of various bioflavonoids on angiotensin II-stimulated contraction by human aortic smooth muscle cells (SMC) embedded in a three-dimensional collagen matrix. Bioflavonoid inhibition of SMC contraction was found to be dependent…

Fat Soluble vitamins affect composition of extracellular matrix deposited by human aortic smooth muscle and endothelial cells in vitro

High blood pressure (hypertension)

Summary Vascular calcification is a pathophysiological process that is associated with coronary atherosclerosis, and is a prognostic marker of cardiovascular morbidity and mortality. The process of arterial wall calcification is triggered and accompanied by pro-osteogenic phenotypical modifications of resident smooth muscle cells (SMC). Vitamin C (ascorbic acid) is an essential nutrient required to support the…

Effects of Various Multi-Nutrient Supplements on the Production and Extracellular Deposition of Collagen I and IV by Human Aortic Smooth Muscle Cells

High blood pressure (hypertension)

Summary Chronic vitamin deficiency is an underlying cause of many modern human chronic diseases, including cardiovascular disease (CVD). A major pathological mechanism leading to the development of CVD is loss of vascular-wall integrity, a structural weakness that triggers the atherosclerotic process. The arterial wall is composed of the constituent cells and surrounding extracellular matrix (ECM).…

Beneficial metabolic effects of Vitamin D on arterial wall cells in vitro

High blood pressure (hypertension)

Summary In recent years, many studies have shown positive effects of vitamin D on health, including various benefits to inflammation and immune response, cognitive function, protection against metabolic syndrome and cardiovascular disease. Vitamin D deficiency has been closely related to the development of coronary heart disease and its mortality.Vitamin D involvement in mitigating the pathogenesis…

Mixture Of Natural Nutrients Reduces Collagen Matrix Contraction Driven By Aortic Smooth Muscle Cells

High blood pressure (hypertension)

Summary Impaired arterial smooth muscle contractility plays a leading role in the development of systemic hypertension. Structural changes, such as occlusive atherosclerotic plaque formation, and functional changes, such as hormonal disturbances, play roles in pathophysiological mechanisms of altered arterial contractility. Accelerated gel contraction was accompanied by elevated secretion of MMPs into cell culture media. We…

Bioflavonoids Effectively Inhibit Smooth Muscle Cell-Mediated Contraction of Collagen Matrix Induced by Angiotensin II

High blood pressure (hypertension)

Summary Introduction: Plant-derived bioflavonoids have been recognized to support arterial wall structural integrity and interfere with a variety of pro-atherosclerotic stimuli. In this study we tested the effects of bioflavonoids on the contractile activity of cultured human aortic smooth muscle cells (SMC) embedded in a three-dimensional type I collagen matrix. Methods: Collagen I solution mixed…

Micronutrient supplementation improves PCOS-typical parameters

Polycystic ovary syndrome

Summary This Austrian trial evaluated whether a micronutrient preparation containing omega-3 fatty acids, antioxidants, and co-enzyme Q10 can influence specific parameters in women with polycystic ovary syndrome, short PCOS, a disorder involving infrequent, irregular or prolonged menstrual periods. The results showed improved parameters in patients receiving the micronutrient supplement, indicating that various micronutrients benefit women…

Antioxidant preparation effective in treatment of endometriosis-associated pelvic pain

Endometriosis

Summary This Spanish trial aimed to assess the impact of an antioxidant preparation with N-acetyl cysteine and alpha lipoic acid on endometriosis-associated pelvic pain. Endometriosis is an often painful disorder in which tissue similar to the lining of the womb starts to grow outside the uterus. 398 endometriosis patients were treated with the preparation for…

Antioxidant supplementation reduces endometriosis-related pelvic pain

Endometriosis

Summary Endometriosis is an often painful disorder in which tissue similar to the lining of the womb starts to grow outside the uterus. This condition is associated with increased levels of oxidative stress. The present trial aimed to assess whether antioxidant supplementation can ameliorate endometriosis-associated symptoms like pelvic pain. 59 women with pelvic pain, endometriosis,…

Composition of natural compounds reduces symptoms in endometriosis patients

Endometriosis

Summary This Italian study aimed to identify natural active ingredients that could reduce various symptoms in endometriosis patients. Endometriosis is an often painful disorder in which tissue similar to the lining of the womb starts to grow outside the uterus. For three months, the patients were treated with a micronutrient composition, including quercetin, curcumin, and…

Specific dietary factors reduce the risk of developing endometriosis

Endometriosis

Summary This review by the Medical University of Silesia, Poland, evaluated literature concerning the correlation of diet and the risk of developing endometriosis, a disease of the female reproductive system. The Polish researchers discovered that consuming fruits and vegetables, antioxidant vitamins, B vitamins, fish oils (omega-3 fatty acids), and dairy products rich in calcium and…

Antioxidant levels related to risk of gestational diabetes

Gestational diabetes

Summary Increased oxidative stress levels have been shown to lead to diabetic problems. This study evaluated the potential of antioxidants to combat oxidative stress by scavenging free radicals (antioxidant capacity) in women with gestational diabetes (40 study participants) and healthy pregnant women (40 participants). Among others, dietary intake was measured using food questionnaires. The results…

Favorable effects of vitamin D supplementation on pregnancy outcomes in gestational diabetes

Gestational diabetes

Summary Vitamin D deficiency is highly prevalent among women with gestational diabetes. This study, executed by Iranian researchers, aimed to assess the effect of vitamin D supplementation on this diabetes type. The trial was performed with 45 pregnant women diagnosed with gestational diabetes who did not take anti-diabetes medication. The participants were randomly assigned to…

Vitamin D associated with diabetic retinopathy

Diabetes type 1 | Diabetes type 2

Summary This study explored the association between advanced diabetes retinopathy (an eye disease caused by high sugar levels) and vitamin D. 889 participants, including patients with diabetic retinopathy and healthy participants, were involved. The results showed that patients with vitamin D deficiency had a significantly higher prevalence of diabetic retinopathy compared to healthy participants with…

Conventional anti-diabetes drugs associated with vitamin B12 deficiency in patients with type 2 diabetes

Diabetes type 2

Summary This Korean study investigated vitamin B12 deficiency in patients with type 2 diabetes using the conventional anti-diabetes drug metformin. 1111 patients with type 2 diabetes, taking metformin for at least 6 months, were included. The study showed that an increased dose of metformin was significantly associated with decreased vitamin B12 levels. Vitamin B12 deficiency…

Relationship between levels of trace elements, oxidative stress and blood sugar control in type 1 diabetes

Diabetes type 1

Summary Taiwanese research departments analyzed the level of zinc and parameters related to free radicals and oxidative stress in type 1 diabetic patients and healthy test persons. Patients with poor controlled glucose (sugar) levels were found to have significantly lower zinc levels. Additionally, levels of oxidative stress were significantly increased in diabetes patients. A significant…

Dietary factors influence the development of Parkinson’s disease

Parkinson's disease

Summary American researchers reviewed several publications investigating the role of environmental factors, including dietary components, in developing Parkinson’s disease. Several of these studies identified important interactions between nutritional factors and the development of Parkinson’s disease. Thus, specific micronutrients can modulate the risk of Parkinson’s disease and, therefore, could be helpful as new therapeutic approaches. More…

Vitamin B12 and homocysteine levels predict disease progression in early Parkinson’s disease

Parkinson's disease

Summary This study, conducted by American researchers, determined vitamin B12 levels in patients with early Parkinson’s disease and their association with the progression of the disease. During the study, vitamin B12 and vitamin B12 determinants like homocysteine (a risk factor for several disorders) were measured in blood collected from participants with early, untreated Parkinson’s disease.…

Relationship between vitamin D levels, bone condition and Parkinson’s disease symptoms

Parkinson's disease

Summary This Chinese study aimed to determine whether vitamin D levels correlate with the conditions of bones and various symptoms in patients with Parkinson’s disease. The study included 182 patients with Parkinson’s disease and 185 healthy people. The scientists detected significantly lower vitamin D levels in patients with Parkinson’s disease than in healthy participants. Furthermore,…

Vitamin D improves balance control in patients with Parkinson’s disease

Parkinson's disease

Summary Balance problems and falls are major causes of morbidity and mortality in patients with Parkinson’s disease. Two research centers in Oregon, USA, therefore investigated the relationship of vitamin D supplementation on balance control and fall reduction. To this end, balance function and vitamin D concentrations were determined by balance tests and blood analyzes. Vitamin…

Dietary intake of antioxidant vitamins beneficially affects risk of Parkinson’s disease

Parkinson's disease

Summary This study, executed by the University of Osaka, Japan, investigated the relationship between the dietary intake of selected antioxidant vitamins, vegetables, and fruits and the risk of Parkinson’s disease in Japan. 249 patients and 368 people without neurodegenerative diseases participated in this study. Dietary intake was recorded by questionnaires. The results showed that higher…