Vitamin C supplementation slightly improves physical activity levels and reduces cold incidence in men with marginal vitamin C status: a randomized controlled trial

Immunomodulatory Effects of Vitamin D and Zinc on Viral Infection

Several nutrients are crucial in enhancing the immune system and preserving the structural integrity of bodily tissue barriers. Vitamin D (VD) and zinc (Zn) have received considerable interest due to their immunomodulatory properties and ability to enhance the body's immune defenses. Due to their antiviral, anti-inflammatory, antioxidative, and immunomodulatory properties, the two nutritional powerhouses VD and Zn are crucial for innate and adaptive immunity. As observed with COVID-19, deficiencies in these micronutrients impair immune responses, increasing susceptibility to viral infections and severe disease. Ensuring an adequate intake of VD and Zn emerges as a promising strategy for fortifying the immune system. Ongoing clinical trials are actively investigating their potential therapeutic advantages. Beyond the immediate context of the pandemic, these micronutrients offer valuable tools for enhancing immunity and overall well-being, especially in the face of future viral threats. This analysis emphasizes the enduring significance of VD and Zn as both treatment and preventive measures against potential viral challenges beyond the current health crisis. The overview delves into the immunomodulatory potential of VD and Zn in combating viral infections, with particular attention to their effects on animals. It provides a comprehensive summary of current research findings regarding their individual and synergistic impacts on immune function, underlining their potential in treating and preventing viral infections. Overall, this overview underscores the need for further research to understand how VD and Zn can modulate the immune response in combatting viral diseases in animals.

Vitamin C reduces the severity of common colds: a meta-analysis

BACKGROUND

Randomized trials have shown that vitamin C shortens the duration of common colds. Some trials reported greater effects on severe cold symptoms compared with mild symptoms. This review systematically compares the effects of vitamin C on severe and mild common cold symptoms.

METHODS

We included all placebo-controlled trials of orally administered vitamin C in doses of at least 1 g/day for the common cold for people in good health at baseline. The analysis was restricted to trials which reported both the total duration of the common cold, and the severity of the common cold measured using severity scales, the duration of more severe stages of the cold, or proxies for severe colds such as days indoors. Findings were pooled using the inverse variance, fixed effect options of the metacont function of the R package meta to calculate the ratio of means estimate.

RESULTS

Fifteen comparisons from 10 trials which reported both mild and severe symptoms were identified. All trials were randomized and double-blind. Compared to placebo, vitamin C significantly decreased the severity of the common cold by 15% (95% CI 9-21%). The direct comparison of the effect of vitamin C on mild and severe symptoms was limited to five comparisons which found that vitamin C had a significant benefit on the duration of severe symptoms. In this subset, there was a significant difference in the size of the effect of vitamin C on the overall duration of colds versus the duration of severe colds (P = 0.002), and vitamin C had no significant effect on the duration of mild symptoms.

CONCLUSIONS

The common cold is the leading cause of acute morbidity and a major cause of absenteeism from work and school. However, absenteeism is dependent on the severity of symptoms. The finding that vitamin C may have a greater effect on more severe measures of the common cold is therefore important. Further research on the therapeutic effects of vitamin C on the common cold should measure outcomes of differing levels of severity.

[Immunonutrition and (its impact on) health. Micronutrients and debilitating factors]

Introduction

Introduction: the interaction between immunity and nutrition is complex and multifaceted. Micronutrients, including vitamins and minerals, are essential for immune function. In turn, immune function and lifestyle habits can affect nutritional needs and micronutrient utilization, creating an interdependence between nutrition and immunity that can be modulated by both external and internal factors. Objectives: to examine the relationship between micronutrient intake and immune function, and how debilitating factors such as aging, disease, and stress can impact this relationship. Methods: a review of scientific evidence and recommendations from major international scientific societies was conducted to identify the importance of micronutrients in immune function and how debilitating factors can alter their impact. Results: the effect of different micronutrients on immune function is described. Debilitating factors like aging, stress, and chronic diseases can compromise the immune system and make the body more susceptible to infections. However, adequate intake of micronutrients and healthy habits can help to strengthen immunity and mitigate the effects of these debilitating factors. Conclusion: immunonutrition is a critical component for maintaining a strong and healthy immune system. Sufficient intake of micronutrients and healthy lifestyle habits can help improve immunity, especially in the presence of debilitating factors.

The Role of Some Vitamins in Respiratory-related Viral Infections: A Narrative Review

This study aimed to find out the effect of vitamins on respiratory-related viral infections, including coronavirus disease 2019 (COVID-19), through the literature reviews. From January 2000 to June 2021, the studies (cohort studies, cross-sectional studies, case-control studies, randomized control trials) related to vitamins (vitamin A, D, E, C, B₆, folate, and B₁₂) and COVID-19/severe acute respiratory syndrome/Middle East respiratory syndrome/cold/influenza were selected from the PubMed, Embase, and Cochrane libraries and analyzed. The relationship between vitamins and virus-related respiratory diseases was identified. Through the review, 39 studies were selected on vitamin D, one study on vitamin E, 11 studies on vitamin C, and 3 studies on folate. Regarding COVID-19, 18 studies on vitamin D, 4 studies on vitamin C, and 2 studies on folate showed significant effects of the intake of these nutrients in preventing COVID-19. Regarding colds and influenza, 3 studies on vitamin D, 1 study on vitamin E, 3 studies on vitamin C, and 1 study on folate demonstrated that the intake of these nutrients significantly prevents these diseases. Therefore, this review suggested the intake of vitamins D, E, C, and folate is important for preventing respiratory diseases related to viruses, such as COVID-19, colds, and influenza. The relationship between these nutrients and virus-related respiratory diseases should be continuously monitored in the future.

Subclinical Vitamin C Plasma Levels Associated with Increased Risk of CAD Diagnosis via Inflammation: Results from the NHANES 2003-2006 Surveys

Vitamin C remains an important, yet frequently unassessed, component of a healthy immune system though it may prove useful in alleviating the chronic inflammatory processes underlying chronic diseases such as coronary artery disease (CAD). Recent research identified a sizeable proportion of the United States population with insufficient vitamin C plasma levels and significant associations to both acute and chronic inflammation. This cross-sectional study used the 2003-2006 NHANES surveys data to extrapolate associations between plasma vitamin C levels (deficiency, hypovitaminosis, inadequate, adequate, and saturating) and CAD through inflammation (C-reactive protein and red cell distribution width). Increased reports of CAD diagnosis were identified in participants with vitamin C deficiency (OR: 2.31, CI: 1.49-3.58) and inadequate plasma levels (OR: 1.39, CI: 1.03-1.87). No significant correlation was identified between any other plasma vitamin C quintiles and CAD. When inflammation was controlled, previous associations in the deficient level of plasma vitamin C were no longer significant in association with CAD and participants with inadequate plasma vitamin C showed a reduced association to CAD diagnoses (OR: 0.33, CI: 0.13-0.86). Most chronic inflammation and vitamin C plasma statuses do not demonstrate specific signs or symptoms until the deficient level of vitamin C and/or disease. Thus, increased surveillance of both, and healthy nutritional habits remain crucial modifiable risk factors for disease prevention.

Can a Short-term Daily Oral Administration of Propolis Improve Muscle Fatigue and Recovery?

This study investigated the effect of 1-week oral administration of propolis on muscle fatigue and recovery after performing a fatigue task (total 100 maximal voluntary concentric knee extension repetitions). In this placebo-controlled, double-blind study, 18 young men consumed a formulation with high Brazilian green propolis dose (H-BGP), a formulation with low Brazilian green propolis dose, or a placebo, for 1 week before performing the fatigue task (an interval between each intervention: 1-2 weeks). Maximal voluntary contraction torque, central fatigue (voluntary activation and root mean square values of the surface electromyography amplitude), and peripheral fatigue (potentiated triplet torque) were assessed before, immediately after, and 2 minutes after the fatigue task. Maximal voluntary contraction torque decreased immediately after the fatigue task in all conditions (P<0.001); however, it recovered from immediately after to 2 minutes after the fatigue task only in the H-BGP condition (P<0.001). Furthermore, there was a significant decrease in voluntary activation (P<0.001) and root mean square values of the surface electromyography amplitude (P≤0.035) only in the placebo condition. No significant difference was observed in the time-course change in potentiated triplet torque between the conditions. These results suggest that oral administration of propolis promotes muscle fatigue recovery by reducing central fatigue.

Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: A systematic review and meta-analysis

It remains uncertain as to whether nutrient supplementation for the general population considered healthy could be useful in the prevention of RTIs, such as COVID-19. In this systematic review and meta-analysis, the evidence was evaluated for primary prevention of any viral respiratory tract infection (RTI) such as SARS-CoV-2, through supplementation of nutrients with a recognized role in immune function: multiple micronutrients, vitamin A, folic acid, vitamin B12, C, D, E, beta-carotene, zinc, iron and long-chain polyunsaturated fatty acids. The search produced 15,163 records of which 93 papers (based on 115 studies) met the inclusion criteria, resulting in 199,055 subjects (191,636 children and 7,419 adults) from 37 countries. Sixty-three studies were included in the meta-analyses, which was performed for children and adults separately. By stratifying the meta-analysis by world regions, only studies performed in Asia showed a significant but heterogeneous protective effect of zinc supplementation on RTIs (RR 0.86, 95% CI 0.7-0.96, I²  = 79.1%, p = .000). Vitamin D supplementation in adults significantly decreased the incidence of RTI (RR 0.89, 95% CI 0.79-0.99, p = .272), particularly in North America (RR 0.82 95% CI 0.68-0.97), but not in Europe or Oceania. Supplementation of nutrients in the general population has either no or at most a very limited effect on prevention of RTIs. Zinc supplementation appears protective for children in Asia, whilst vitamin D may protect adults in the USA and Canada. In 10/115 (8.7%) studies post-hoc analyses based on stratification for nutritional status was performed. In only one study zinc supplementation was found to be more effective in children with low zinc serum as compared to children with normal zinc serum levels.

Association of vitamin and/or nutritional supplements with fall among patients with diabetes: A prospective study based on ACCORD and UK Biobank

Aims

To assess the associations of vitamin and/or nutritional supplements (VNS) with falls among patients with diabetes.

Methods

9,141 and 21,489 middle-aged participants with diabetes from Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial and UK Biobank were included. Use of VNS was collected at baseline, and fall events were recorded using annual questionnaires in ACCORD and electric records in UK Biobank during follow-up. The associations of VNS use with fall risk were analyzed using logistic regression models in ACCORD and Fine-Gray sub-distribution hazard models in UK Biobank. The role of specific supplements was also estimated in UK Biobank, adjusting for confounding factors and multiple comparisons.

Results

45.9% (4,193/9,141, 5.5 median follow-up years) patients in ACCORD and 10.5% (2,251/21,489, 11.9 median follow-up years) in UK Biobank experienced fall and in-patient events during follow-up, respectively. In ACCORD, VNS using was associated with an increased risk of fall (full-adjusted odds ratio [OR]: 1.26, P < 0.05). In UK Biobank, despite no significant association between VNS overall and in-patient fall, vitamin B, calcium, and iron using increased the risk of falls significantly (full-adjusted hazard ratio range: 1.31-1.37, P < 0.05).

Conclusions

Use of specific VNS increased the risk of fall among patients with diabetes. The non-indicative use of nutritional supplements for patients with diabetes might be inadvisable.

Nutritional risk factors for SARS-CoV-2 infection: a prospective study within the NutriNet-Santé cohort

BACKGROUND

Nutritional factors are essential for the functioning of the immune system and could therefore play a role in COVID-19 but evidence is needed. Our objective was to study the associations between diet and the risk of SARS-CoV-2 infection in a large population-based sample.

METHODS

Our analyses were conducted in the French prospective NutriNet-Santé cohort study (2009-2020). Seroprevalence of anti-SARS-CoV-2 antibodies was assessed by ELISA on dried blood spots. Dietary intakes were derived from repeated 24 h dietary records (at least 6) in the two years preceding the start of the COVID-19 pandemic in France (February 2020). Multi-adjusted logistic regression models were computed.

RESULTS

A total of 7766 adults (70.3% women, mean age: 60.3 years) were included, among which 311 were positive for anti-SARS-CoV-2 antibodies. Dietary intakes of vitamin C (OR for 1 SD=0.86 (0.75-0.98), P=0.02), vitamin B9 (OR=0.84 (0.72-0.98), P=0.02), vitamin K (OR=0.86 (0.74-0.99), P=0.04), fibers (OR=0.84 (0.72-0.98), P=0.02), and fruit and vegetables (OR=0.85 (0.74-0.97), P=0.02) were associated to a decreased probability of SARS-CoV-2 infection while dietary intakes of calcium (OR=1.16 (1.01-1.35), P=0.04) and dairy products (OR=1.19 (1.06-1.33), P=0.002) associated to increased odds. No association was detected with other food groups or nutrients or with the overall diet quality.

CONCLUSIONS

Higher dietary intakes of fruit and vegetables and, consistently, of vitamin C, folate, vitamin K and fibers were associated with a lower susceptibility to SARS-CoV-2 infection. Beyond its established role in the prevention of non-communicable diseases, diet could therefore also contribute to prevent some infectious diseases such as COVID-19.

Common anti-oxidant vitamin C as an anti-infective agent with remedial role on SARS-CoV-2 infection. An update

Coronavirus disease -2019 (COVID-19) has led to a worldwide multifaceted crisis. The medical world agonizes to contend with the problem, but a string of tested medications has been proven unavailing. Vitamin C is well described as a salutary antioxidant and some trials conclude that it may be a potential antiviral drug. In high doses, Vitamin C can alternate crucial steps in the pathogenesis of sepsis and acute respiratory distress syndrome. This dynamic was the driving force behind trials around the world that tried immunonutrition as a weapon against clinical entities. We summarize the mechanisms of action of Vitamin C and its role against infections and the current literature referring to the potential role of Vitamin C in SARS-CoV-2 infection, also as a contingent treatment agent.

ALSUntangled #62: vitamin C

Vitamin C is one of the most common supplements taken by people with ALS. As an antioxidant, it has a plausible mechanism for slowing disease progression and there are some flawed pre-clinical studies and case reports suggesting benefit. However, a small human trial showed no benefit. Given this negative trial, we do not currently advise vitamin C as an ALS treatment.

Low level of Vitamin C and dysregulation of Vitamin C transporter might be involved in the severity of COVID-19 Infection

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been spreading around the world at an exponential pace, leading to millions of individuals developing the associated disease called COVID-19. Due to the novel nature and the lack of immunity within humans, there has been a collective global effort to find effective treatments against the virus. This has led the scientific community to repurpose Food and Drug Administration (FDA) approved drugs with known safety profiles. Of the many possible drugs, vitamin C has been on the shortlist of possible interventions due to its beneficial role as an immune booster and inherent antioxidant properties. Within this manuscript, a detailed discussion regarding the intracellular function and inherent properties of vitamin C is conducted. It also provides a comprehensive review of published research pertaining to the differences in expression of the vitamin C transporter under several pathophysiologic conditions. Finally, we review recently published research investigating the efficacy of vitamin C administration in treating viral infection and life-threatening conditions. Overall, this manuscript aims to present existing information regarding the extent to which vitamin C can be an effective treatment for COVID-19 and possible explanations as to why it may work in some individuals but not in others.

Vitamin C supplementation is necessary for patients with coronavirus disease: An ultra-high-performance liquid chromatography-tandem mass spectrometry finding

To administer vitamin C (VC) with precision to patients with the coronavirus disease (COVID-19), we developed an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to assess plasma VC concentrations. 31 patients with COVID-19 and 51 healthy volunteers were enrolled. VC stability was evaluated in blood, plasma, and precipitant-containing stabilizers. A proportion of 7.7 % of VC was degraded in blood at room temperature (RT) (approximately 20–25 °C) at 1.5 h post administration with respect to the proportion degraded at 0.5 h, but without statistical difference. VC was stable in plasma for 0.75 h at RT, 2 h at 4 °C, 5 days at −40 °C, and 4 h in precipitant-containing stabilizer (2 % oxalic acid) at RT. The mean plasma concentration of VC in patients with COVID-19 was 2.00 mg/L (0.5–4.90) (n = 8), which was almost 5-fold lower than that in healthy volunteers (9.23 mg/L (3.09. 35.30)) (n = 51). After high-dose VC treatment, the mean VC concentration increased to 13.46 mg/L (3.93. 34.70) (n = 36), higher than that in healthy volunteers, and was within the normal range (6–20 mg/L). In summary, we developed a simple UPLC-MS/MS method to quantify VC in plasma, and determined the duration for which the sample remained stable. VC levels in patients with COVID-19 were considerably low, and supplementation at 100 mg/kg/day is considered highly essential.

Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis

Acute respiratory tract infections (ARIs) are a leading cause of ill-health and death globally. Individual or multiple micronutrients have been shown to modulate immune function and affect the risk and severity of a number of infectious diseases. We systematically reviewed the evidence on the impact of micronutrient supplements to reduce the occurrence of ARIs and shorten the duration of ARI symptoms among adults. Random effects meta-analyses were conducted to estimate the pooled effects of vitamin D, vitamin C, zinc and multiple micronutrient supplementation (MMS) on the occurrence of ARIs and the duration of ARI symptoms. Vitamin D supplementation reduced the risk of ARI (risk ratio (RR)=0.97; 95% CI 0.94 to 1.00; p=0.028) and shortened the duration of symptoms (per cent difference: -6% (95% CI -9% to -2%; p=0.003)). The RR of vitamin D to prevent ARI was farther from the null when diagnosis was based on clinical diagnosis or laboratory testing, compared with self-report and when the loading dose was <60 000 IU. Vitamin C supplementation reduced the risk of ARIs (RR=0.96; 95% CI 0.93 to 0.99; p=0.01) and shortened the duration of symptoms (per cent difference: -9% (95% CI -16% to -2%; p=0.014)). The effect of vitamin C on preventing ARI was stronger among men and in middle-income countries, compared with women and high-income countries, respectively. Zinc supplementation did not reduce the risk of ARIs but shortened the duration of symptoms substantially (per cent difference: -47% (95% CI -73% to -21%; p=0.0004)). Our synthesis of global evidence from randomised controlled trials indicates that micronutrient supplements including zinc, vitamins C and D, and multiple micronutrient supplements may be modestly effective in preventing ARIs and improving their clinical course. Further research is warranted to better understand the effectiveness that individual or multiple micronutrients have on SARS-CoV-2 infection and treatment outcomes.

Zinc, Vitamin D and Vitamin C: Perspectives for COVID-19 With a Focus on Physical Tissue Barrier Integrity

Some nutrients play key roles in maintaining the integrity and function of the immune system, presenting synergistic actions in steps determinant for the immune response. Among these elements, zinc and vitamins C and D stand out for having immunomodulatory functions and for playing roles in preserving physical tissue barriers. Considering the COVID-19 pandemic, nutrients that can optimize the immune system to prevent or lower the risk of severe progression and prognosis of this viral infection become relevant. Thus, the present review aims to provide a comprehensive overview of the roles of zinc and vitamins C and D in the immune response to viral infections, focusing on the synergistic action of these nutrients in the maintenance of physical tissue barriers, such as the skin and mucous membranes. The evidence found in the literature shows that deficiency of one or more of these three elements compromises the immune response, making an individual more vulnerable to viral infections and to a worse disease prognosis. Thus, during the COVID-19 pandemic, the adequate intake of zinc and vitamins C and D may represent a promising pharmacological tool due to the high demand for these nutrients in the case of contact with the virus and onset of the inflammatory process. Ongoing clinical trials will help to clarify the role of these nutrients for COVID-19 management.

Opinions on the current pandemic of COVID-19: Use functional food to boost our immune functions

The pandemic of novel coronavirus caused COVID-19 had resulted in a high number of hospitalizations and deaths and caused a devastating toll on human and society health. The symptoms of the infected patients vary significantly, from life-threatening to mild or even asymptomatic. This clinical observation led to hypothesize on the critical role of host innate immunity in the disease development and progression. As the first defense barrier against microorganisms, the innate immune reaction determines not only the viral infection rate but also immune-mediated response. Therefore, promote healthy behaviors to enhance innate immunity with functional food and nutritional agents may be a rational strategy for minimizing damages caused by viruses to global health.

The Role of Vitamin C as Adjuvant Therapy in COVID-19

Background and objective

The anti-inflammatory properties of vitamin C (VC) and the promising results it has shown in the treatment for common cold have prompted clinicians to use it as adjuvant therapy in the treatment of COVID-19. The purpose of this study was to find out the role of VC as adjunctive therapy in coronavirus disease 2019 (COVID-19).

Methodology

This study was conducted from March to July 2020 in the COVID-19 unit of a tertiary care hospital in Karachi. In this randomized controlled trial (RCT), one group received the intervention [50 mg/kg/day of intravenous (IV) VC] along with the standard therapy, and the other group received standard therapy only. Data such as age, gender, vitals, and biochemical values as well as outcomes including the number of days required for treatment, hospital stay, need for ventilation, and mortality were compared between the two groups and recorded using a self-structured questionnaire.

Results

COVID-19 patients who received IV VC became symptom-free earlier (7.1 ± 1.8 vs. 9.6 ± 2.1 days, p-value: <0.0001) and spent fewer days in the hospital (8.1 ± 1.8 vs. 10.7 ± 2.2 days, p-value: <0.0001) compared to those who received standard therapy only. However, there was no significant difference in the need for mechanical ventilation (p-value: 0.406) and mortality (p-value: 0.31) between the two groups.

Conclusion

VC can significantly improve clinical symptoms in patients affected with COVID-19; however, it had no impact on mortality and the need for mechanical ventilation. More large-scale studies are required to further assess the role of VC in the treatment of COVID-19.

Ascorbic acid improves extrapyramidal syndromes and corpus striatal degeneration induced by dopamine-2 receptor inhibition in Wistar rats

Objectives The prolonged uses of fourth-generation antipsychotics have been implicated in inducing extrapyramidal syndromes characterized by the motor deficit. This was attributed to the loss of dopamine-2 receptor (D2R) signaling. However, ascorbic acid (SVCT2R stimulation) in the brain is proposed to modulate D2R activity. We, therefore, investigated the beneficial roles of ascorbic acid in improving the extrapyramidal symptoms seen in D2R loss. Methods Twenty adult male Wistar rats of average weight 200 g were distributed randomly into four groups. The control (NS) received normal saline for 28 days, Untreated D2R inhibition group (-D2R) received normal saline for seven days and then subsequently received chlorpromazine for 21 days, D2R inhibition group treated with ascorbic acid (-D2R+SVCT2R) received chlorpromazine for 21 days and was subsequently treated with ascorbate for seven days while the withdrawal group (WG) received chlorpromazine for 21 days and subsequently received normal saline for seven days. Motor deficits were assessed using a rotarod and cylinder test. The corpus striatum was harvested, processed, and stained using H&E and Nissl stains. Cellular density was analyzed using Image J software 1.8.0. Results Motor deficit was observed in -D2R animals administered chlorpromazine with less improvement in WG compared to control (p<0.05) in both rotarod and cylinder test. Ascorbic acid (SVCT2R stimulation) significantly (p<0.001) improved the latency of fall and climbing attempts observed in -D2R animals. The density of basophilic trigoid bodies was significantly (p<0.001) restored in -D2R+SVCT2R group, suggesting recovery of neural activity in the corpus striatum. Moreover, the hallmarks of neuronal degeneration were less expressed in the ascorbic acid treatment groups. Conclusions Ascorbic acid putatively ameliorates extrapyramidal symptoms observed in D2R blockage by chlorpromazine in Wistar rats.

The Role of Micronutrients in Support of the Immune Response against Viral Infections

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

KiwiC for Vitality: Results of a Randomized Placebo-Controlled Trial Testing the Effects of Kiwifruit or Vitamin C Tablets on Vitality in Adults with Low Vitamin C Levels

Consumption of vitamin C-rich fruit and vegetables has been associated with greater feelings of vitality. However, these associations have rarely been tested in randomized controlled trials. The aim of the current study was to test the effects of eating a vitamin C-rich food (kiwifruit) on subjective vitality and whether effects are driven by vitamin C. Young adults (n = 167, 61.1% female, aged 18-35) with plasma vitamin C <40 µmol/L were randomized into three intervention conditions: kiwifruit (2 SunGold™ kiwifruit/day), vitamin C (250 mg tablet/day), placebo (1 tablet/day). The trial consisted of a two-week lead-in, four-week intervention, and two-week washout. Plasma vitamin C and vitality questionnaires (total mood disturbance, fatigue, and well-being) were measured fortnightly. Self-reported sleep quality and physical activity were measured every second day through smartphone surveys. Nutritional confounds were assessed using a three-day food diary during each study phase. Plasma vitamin C reached saturation levels within two weeks for the kiwifruit and vitamin C groups. Participants consuming kiwifruit showed significantly improved mood and well-being during the intervention period; improvements in well-being were sustained during washout. Decreased fatigue and increased well-being were observed following intake of vitamin C alone, but only for participants with consistently low vitamin C levels during lead-in. Diet records showed that participants consuming kiwifruit reduced their fat intake during the intervention period. Intervention effects remained significant when adjusting for age and ethnicity, and were not explained by sleep quality, physical activity, BMI, or other dietary patterns, including fat intake. There were no changes in plasma vitamin C status or vitality in the placebo group. Whole food consumption of kiwifruit improved subjective vitality in adults with low vitamin C status. Similar, but not identical, changes were found for vitamin C tablets suggesting that additional properties of kiwifruit may contribute to improved vitality.

Low Vitamin C Status in Patients with Cancer Is Associated with Patient and Tumor Characteristics

Vitamin C (ascorbate) acts as an antioxidant and enzyme cofactor, and plays a vital role in human health. Vitamin C status can be affected by illness, with low levels being associated with disease due to accelerated turnover. However, robust data on the ascorbate status of patients with cancer are sparse. This study aimed to accurately measure ascorbate concentrations in plasma from patients with cancer, and determine associations with patient or tumor characteristics. We recruited 150 fasting patients with cancer (of 199 total recruited) from two cohorts, either prior to cancer surgery or during cancer chemo- or immunotherapy. A significant number of patients with cancer had inadequate plasma ascorbate concentrations. Low plasma status was more prevalent in patients undergoing cancer therapy. Ascorbate status was higher in women than in men, and exercising patients had higher levels than sedentary patients. Our study may prompt increased vigilance of ascorbate status in cancer patients.

Inadequacy of Immune Health Nutrients: Intakes in US Adults, the 2005-2016 NHANES

A well-functioning immune system is essential for human health and well-being. Micronutrients such as vitamins A, C, D, E, and zinc have several functions throughout the immune system, yet inadequate nutrient intakes are pervasive in the US population. A large body of research shows that nutrient inadequacies can impair immune function and weaken the immune response. Here, we present a new analysis of micronutrient usual intake estimates based on nationally representative data in 26,282 adults (>19 years) from the 2005-2016 National Health and Nutrition Examination Surveys (NHANES). Overall, the prevalence of inadequacy (% of population below estimated average requirement [EAR]) in four out of five key immune nutrients is substantial. Specifically, 45% of the U.S. population had a prevalence of inadequacy for vitamin A, 46% for vitamin C, 95% for vitamin D, 84% for vitamin E, and 15% for zinc. Dietary supplements can help address nutrient inadequacy for these immune-support nutrients, demonstrated by a lower prevalence of individuals below the EAR. Given the long-term presence and widening of nutrient gaps in the U.S.-specifically in critical nutrients that support immune health-public health measures should adopt guidelines to ensure an adequate intake of these micronutrients. Future research is needed to better understand the interactions and complexities of multiple nutrient shortfalls on immune health and assess and identify optimal levels of intake in at-risk populations.

Dietary Vitamin C Deficiency Is Associated With Health-Related Quality of Life and Cardiac Event-free Survival in Adults With Heart Failure

BACKGROUND

Vitamin C deficiency is prevalent in adults with heart failure (HF). Little is known about the relationship of dietary vitamin C deficiency with health outcomes in adults with HF.

OBJECTIVE

The study's aim was to determine the relationships of vitamin C deficiency measured at baseline with health-related quality of life (HRQOL) and cardiac event-free survival in patients with HF measured 1 year later.

METHOD

A total of 251 patients with HF completed a 4-day food diary. Dietary vitamin C deficiency was defined as daily intake less than the estimated average requirement from the Institute of Medicine of 75 mg/d for men and 60 mg/d for women. Health-related quality of life was assessed using the Minnesota Living with Heart Failure Questionnaire at 12 months. Patients were followed for a median of 1 year to determine time to the first event of cardiac-related hospitalization or death. Data were analyzed by hierarchical linear and Cox proportional hazards regressions.

RESULTS

One hundred patients (40%) had vitamin C deficiency. Dietary vitamin C deficiency was associated with poorer HRQOL at 12 months (β = 0.16, P = .02) after controlling for demographic and clinical variables. During the follow-up period, 59 patients (24%) had cardiac events. In Cox regression, vitamin C deficiency predicted shorter cardiac event-free survival after adjusting for the same covariates (hazards ratio, 1.95; 95% confidence interval, 1.08-3.51).

CONCLUSION

Vitamin C deficiency was associated with poorer HRQOL and shorter cardiac event-free survival in patients with HF. The findings suggest that encouraging patients with HF to consume a diet rich in fruits/vegetables to prevent vitamin C deficiency may lead to better health outcomes.

A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection

Immune support by micronutrients is historically based on vitamin C deficiency and supplementation in scurvy in early times. It has since been established that the complex, integrated immune system needs multiple specific micronutrients, including vitamins A, D, C, E, B6, and B12, folate, zinc, iron, copper, and selenium, which play vital, often synergistic roles at every stage of the immune response. Adequate amounts are essential to ensure the proper function of physical barriers and immune cells; however, daily micronutrient intakes necessary to support immune function may be higher than current recommended dietary allowances. Certain populations have inadequate dietary micronutrient intakes, and situations with increased requirements (e.g., infection, stress, and pollution) further decrease stores within the body. Several micronutrients may be deficient, and even marginal deficiency may impair immunity. Although contradictory data exist, available evidence indicates that supplementation with multiple micronutrients with immune-supporting roles may modulate immune function and reduce the risk of infection. Micronutrients with the strongest evidence for immune support are vitamins C and D and zinc. Better design of human clinical studies addressing dosage and combinations of micronutrients in different populations are required to substantiate the benefits of micronutrient supplementation against infection.

Vitamin C in Plants: From Functions to Biofortification

Vitamin C (l-ascorbic acid) is an excellent free radical scavenger, not only for its capability to donate reducing equivalents but also for the relative stability of the derived monodehydroascorbate radical. However, vitamin C is not only an antioxidant, since it is also a cofactor for numerous enzymes involved in plant and human metabolism. In humans, vitamin C takes part in various physiological processes, such as iron absorption, collagen synthesis, immune stimulation, and epigenetic regulation. Due to the functional loss of the gene coding for l-gulonolactone oxidase, humans cannot synthesize vitamin C; thus, they principally utilize plant-based foods for their needs. For this reason, increasing the vitamin C content of crops could have helpful effects on human health. To achieve this objective, exhaustive knowledge of the metabolism and functions of vitamin C in plants is needed. In this review, the multiple roles of vitamin C in plant physiology as well as the regulation of its content, through biosynthetic or recycling pathways, are analyzed. Finally, attention is paid to the strategies that have been used to increase the content of vitamin C in crops, emphasizing not only the improvement of nutritional value of the crops but also the acquisition of plant stress resistance.

From in planta Function to Vitamin-Rich Food Crops: The ACE of Biofortification

Humans are highly dependent on plants to reach their dietary requirements, as plant products contribute both to energy and essential nutrients. For many decades, plant breeders have been able to gradually increase yields of several staple crops, thereby alleviating nutritional needs with varying degrees of success. However, many staple crops such as rice, wheat and corn, although delivering sufficient calories, fail to satisfy micronutrient demands, causing the so called 'hidden hunger.' Biofortification, the process of augmenting nutritional quality of food through the use of agricultural methodologies, is a pivotal asset in the fight against micronutrient malnutrition, mainly due to vitamin and mineral deficiencies. Several technical advances have led to recent breakthroughs. Nutritional genomics has come to fruition based on marker-assisted breeding enabling rapid identification of micronutrient related quantitative trait loci (QTL) in the germplasm of interest. As a complement to these breeding techniques, metabolic engineering approaches, relying on a continuously growing fundamental knowledge of plant metabolism, are able to overcome some of the inevitable pitfalls of breeding. Alteration of micronutrient levels does also require fundamental knowledge about their role and influence on plant growth and development. This review focuses on our knowledge about provitamin A (beta-carotene), vitamin C (ascorbate) and the vitamin E group (tocochromanols). We begin by providing an overview of the functions of these vitamins in planta, followed by highlighting some of the achievements in the nutritional enhancement of food crops via conventional breeding and genetic modification, concluding with an evaluation of the need for such biofortification interventions. The review further elaborates on the vast potential of creating nutritionally enhanced crops through multi-pathway engineering and the synergistic potential of conventional breeding in combination with genetic engineering, including the impact of novel genome editing technologies.

Immune Function and Micronutrient Requirements Change over the Life Course

As humans age, the risk and severity of infections vary in line with immune competence according to how the immune system develops, matures, and declines. Several factors influence the immune system and its competence, including nutrition. A bidirectional relationship among nutrition, infection and immunity exists: changes in one component affect the others. For example, distinct immune features present during each life stage may affect the type, prevalence, and severity of infections, while poor nutrition can compromise immune function and increase infection risk. Various micronutrients are essential for immunocompetence, particularly vitamins A, C, D, E, B2, B6, and B12, folic acid, iron, selenium, and zinc. Micronutrient deficiencies are a recognized global public health issue, and poor nutritional status predisposes to certain infections. Immune function may be improved by restoring deficient micronutrients to recommended levels, thereby increasing resistance to infection and supporting faster recovery when infected. Diet alone may be insufficient and tailored micronutrient supplementation based on specific age-related needs necessary. This review looks at immune considerations specific to each life stage, the consequent risk of infection, micronutrient requirements and deficiencies exhibited over the life course, and the available evidence regarding the effects of micronutrient supplementation on immune function and infection.

Potential common factors associated with predisposition to common cold in middle-aged and elderly Japanese: A community-based cross-sectional study

People worldwide frequently catch a common cold, which occasionally develops into secondary severe conditions such as pneumonia. However, it is unclear whether predisposition to the common cold is associated with the individual's characteristics including age, body weight, lifestyles, diets, and intestinal functions, besides exposure to a responsible pathogen. We addressed this issue epidemiologically considering many relevant clinical factors.We reviewed data from a cross-sectional study consisting of 39,524 apparently healthy Japanese aged 40 to 79 years (26,975 men and 12,549 women) who underwent a checkup in 2007. Self-reported predisposition to common cold (SPCC) and relevant clinical conditions and parameters were considered.We observed no significant difference in most clinical parameters including age, body mass index (BMI), glycated hemoglobin (HbA1c), and prevalence of men and current smokers between subjects with and without SPCC. In univariate analysis, circulating white blood cell (WBC) count and serum alanine-aminotransferase (ALT) were significantly higher in subjects with SPCC than in those without, whereas serum high-density lipoprotein cholesterol (HDL-C) and duration of sleep were lower. In logistic regression analysis after full adjustment for relevant confounding factors, BMI categories except BMI of ≥27.0 kg/m were significantly associated with SPCC compared with BMI of 23.0 to 24.9 kg/m. Short duration of sleep (≤5 hours), occasional alcohol drinking, and no-exercise were significantly associated with SPCC compared with 7 hours sleep duration, no-drinking alcohol, and low frequent exercise (twice per month), respectively. All gastrointestinal disorders (gastric complaints, constipation, and diarrhea) were independently associated with SPCC. Imbalanced diet and taking a snack were also associated with SPCC in a degree dependent manner. Furthermore, WBC count, serum ALT, and HDL-C (as continuous variables) were associated with SPCC (HDL-C was inversely), whereas no significant association was observed between SPCC and age, smoking, HbA1c, and pharmacotherapy for diabetes, hypertension, and dyslipidemia.Our results demonstrated that multifactorial conditions and parameters might be simultaneously associated with the predisposition to common cold. Prospective studies including detailed common cold questionnaire and measurements are needed to confirm currently suspected causative and protective factors.

Vitamin C and Immune Function

Vitamin C is an essential micronutrient for humans, with pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C supports epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby potentially protecting against environmental oxidative stress. Vitamin C accumulates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is also needed for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis/NETosis and potential tissue damage. The role of vitamin C in lymphocytes is less clear, but it has been shown to enhance differentiation and proliferation of B- and T-cells, likely due to its gene regulating effects. Vitamin C deficiency results in impaired immunity and higher susceptibility to infections. In turn, infections significantly impact on vitamin C levels due to enhanced inflammation and metabolic requirements. Furthermore, supplementation with vitamin C appears to be able to both prevent and treat respiratory and systemic infections. Prophylactic prevention of infection requires dietary vitamin C intakes that provide at least adequate, if not saturating plasma levels (i.e., 100–200 mg/day), which optimize cell and tissue levels. In contrast, treatment of established infections requires significantly higher (gram) doses of the vitamin to compensate for the increased inflammatory response and metabolic demand.

Vitamin C in Stem Cell Biology: Impact on Extracellular Matrix Homeostasis and Epigenetics

Transcription factors and signaling molecules are well-known regulators of stem cell identity and behavior; however, increasing evidence indicates that environmental cues contribute to this complex network of stimuli, acting as crucial determinants of stem cell fate. l-Ascorbic acid (vitamin C (VitC)) has gained growing interest for its multiple functions and mechanisms of action, contributing to the homeostasis of normal tissues and organs as well as to tissue regeneration. Here, we review the main functions of VitC and its effects on stem cells, focusing on its activity as cofactor of Fe⁺²/αKG dioxygenases, which regulate the epigenetic signatures, the redox status, and the extracellular matrix (ECM) composition, depending on the enzymes' subcellular localization. Acting as cofactor of collagen prolyl hydroxylases in the endoplasmic reticulum, VitC regulates ECM/collagen homeostasis and plays a key role in the differentiation of mesenchymal stem cells towards osteoblasts, chondrocytes, and tendons. In the nucleus, VitC enhances the activity of DNA and histone demethylases, improving somatic cell reprogramming and pushing embryonic stem cell towards the naive pluripotent state. The broad spectrum of actions of VitC highlights its relevance for stem cell biology in both physiology and disease.

Vitamin C and Infections

In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose-response, for the duration of common cold symptoms, with up to 6-8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3-4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.

Temporal trends in dietary supplement prescriptions of United States military service members suggest a decrease in pyridoxine and increase in vitamin D supplements from 2005 to 2013

Dietary supplements (DSs) can be obtained over-the-counter but can also be prescribed by health-care providers for therapeutic reasons. Few studies have documented this later source despite the fact that 79% of physicians and 82% of nurses have recommended DSs to patients. This investigation assessed prevalence and temporal trends in oral DS prescriptions filled by all United States service members (SMs) from 2005 to 2013 (n = 1 427 080 ± 22 139, mean ± standard deviation (SD)/y). We hypothesize that there would be temporal variations in specific types of DSs. Data obtained from Department of Defense Pharmacy Data Transaction System were grouped by American Hospital Formulary System pharmacologic-therapeutic classifications and prevalence examined over time. About 11% of SMs filled one or more DS prescriptions of 235 180 ± 4926 (mean ± SD) prescriptions/y over the 9-year period. Curve-fitting techniques indicated significant linear declines over time for multivitamins (P = .004), iron preparations (P < .001), antacids (P < .001), and vitamin B and B complex vitamins (P < .001). There were significant quadratic trends indicating a rise in early years followed by a leveling off in later years for replacement preparations (P < .001) and vitamin C (P < .001). There were significant quadratic trends (P < .001) for vitamin E indicating a decline in early years and leveling off in later years, and vitamin D indicating little change in early years followed by a large rise subsequently (P < .001). This study identified temporal trends in specific DS categories that may be associated with changing perceptions of prescribers and/or patients of the appropriate roles of DSs in medicine and public health.

Plant-Based Nutraceutical Increases Plasma Catalase Activity in Healthy Participants: A Small Double-Blind, Randomized, Placebo-Controlled, Proof of Concept Trial

Oxidative stress resulting from dietary, lifestyle and environmental factors is strongly associated with tissue damage and aging. It occurs when there is either an overproduction of reactive oxygen species (i.e., oxidants) or decreased bioavailability of antioxidants that can scavenge them. The objective of this 12-week double-blind placebo-controlled study was to assess the efficacy of a nutraceutical at augmenting antioxidant status. Healthy adults (25-45 y) were randomized to either a treatment group (Product B, n = 23) or a placebo group (control, n = 20). No significant effect of Product B was observed for anthropometric variables or markers of glucose and lipid regulation. Biomarkers of oxidative stress were likewise not altered following the 12-week intervention. Plasma catalase concentrations were significantly elevated following 12 weeks of Product B as compared to the control group (+6.1 vs. -10.3 nmol/min/mL, p = 0.038), whereas other measures of antioxidant capacity were not significantly different between the groups. Product B effectively augmented concentrations of the anti-aging antioxidant catalase in healthy adults.

Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial

Intercontinental air travel can be stressful, especially for respiratory health. Elderberries have been used traditionally, and in some observational and clinical studies, as supportive agents against the common cold and influenza. This randomized, double-blind placebo-controlled clinical trial of 312 economy class passengers travelling from Australia to an overseas destination aimed to investigate if a standardised membrane filtered elderberry (Sambucus nigra L.) extract has beneficial effects on physical, especially respiratory, and mental health. Cold episodes, cold duration and symptoms were noted in a daily diary and assessed using the Jackson score. Participants also completed three surveys containing questions regarding upper respiratory symptoms (WURSS-21) and quality of life (SF-12) at baseline, just before travel and at 4-days after travel. Most cold episodes occurred in the placebo group (17 vs. 12), however the difference was not significant (p = 0.4). Placebo group participants had a significantly longer duration of cold episode days (117 vs. 57, p = 0.02) and the average symptom score over these days was also significantly higher (583 vs. 247, p = 0.05). These data suggest a significant reduction of cold duration and severity in air travelers. More research is warranted to confirm this effect and to evaluate elderberry's physical and mental health benefits.

Validity of a Semi-Quantitative Food Frequency Questionnaire for Collegiate Athletes

Background

Food frequency questionnaires (FFQs) have been developed and validated for various populations. To our knowledge, however, no FFQ has been validated for young athletes. Here, we investigated whether an FFQ that was developed and validated to estimate dietary intake in middle-aged persons was also valid for estimating that in young athletes.

Methods

We applied an FFQ that had been developed for the Japan Public Health Center-based Prospective Cohort Study with modification to the duration of recollection. A total of 156 participants (92 males) completed the FFQ and a 3-day non-consecutive 24-hour dietary recall (24hDR). Validity of the mean estimates was evaluated by calculating the percentage differences between the 24hDR and FFQ. Ranking estimation was validated using Spearman’s correlation coefficient (CC), and the degree of miscategorization was determined by joint classification.

Results

The FFQ underestimated energy intake by approximately 10% for both males and females. For 35 nutrients, the median (range) deattenuated CC was 0.30 (0.10 to 0.57) for males and 0.32 (−0.08 to 0.62) for females. For 19 food groups, the median (range) deattenuated CC was 0.32 (0.17 to 0.72) for males and 0.34 (−0.11 to 0.58) for females. For both nutrient and food group intakes, cross-classification analysis indicated extreme miscategorization rates of 3% to 5%.

Conclusions

An FFQ developed and validated for middle-aged persons had comparable validity among young athletes. This FFQ might be useful for assessing habitual dietary intake in collegiate athletes, especially for calcium, vitamin C, vegetables, fruits, and milk and dairy products.

Intake of antioxidants and subsequent decline in physical function in a racially/ethnically diverse population

OBJECTIVES

Oxidative stress is considered a risk factor for physical function (PF) decline with aging. The objective of this study was to examine the relationship between antioxidant intake and change in PF over a 5-year period.

DESIGN, SETTING, PARTICIPANTS

The Boston Area Community Health (BACH) Survey is a population-based longitudinal study including 5,502 racially/ethnically diverse and randomly selected participants aged 30-79 years.

MEASUREMENTS

In total, 2828 persons aged 30-79 years completed the validated Block Food Frequency Questionnaire (FFQ) and participated in the follow-up study. Change in PF from baseline (2002-2005) to follow-up (2006-2010) was assessed using the validated SF-12 questionnaire. Linear models were used to examine the association between energy-adjusted quartiles of vitamins C, E and carotenoids and change in PF.

RESULTS

A low intake (first quartile) of vitamin E was associated with a greater decline in PF compared with the highest quartile, with a mean difference in change in PF of -1.73 (95%CI:-3.31,-0.15). Notably, this mean difference was clinically meaningful as it was equivalent to the effect estimate we found for participants who were approximately 15 years apart in age in our cohort, as 1 year increase in age was associated with a mean difference in change in PF of -0.11 (95%CI:-0.16,-0.06). PF decline was not significantly different in the lowest compared with the highest quartile of vitamin C (mean difference=-1.29, 95%CI:-2.61, 0.03) or carotenoids (mean difference=-0.62, 95%CI:-2.22,0.99).

CONCLUSIONS

Low intake of vitamin E was significantly associated with decline in PF with aging. These results are clinically meaningful, extend previous findings that oxidative stress contributes to PF decline, and may inform the development of future prevention strategies aimed at reducing this clinical and public health problem.