This review will provide an overview of the immune system and then describe the effects of frailty, obesity, specific micronutrients and the gut microbiota on immunity and susceptibility to infection including data from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic where relevant. A key role for the immune system is providing host defence against pathogens. Impaired immunity predisposes to infections and to more severe infections and weakens the response to vaccination. A range of nutrients, including many micronutrients, play important roles in supporting the immune system to function. The immune system can decline in later life and this is exaggerated by frailty. The immune system is also weakened with obesity, generalised undernutrition and micronutrient deficiencies, which all result in increased susceptibility to infection. Findings obtained during the SARS-CoV-2 pandemic support what was already known about the effects of ageing, frailty and obesity on immunity and susceptibility to infection. Observational studies conducted during the pandemic also support previous findings that multiple micronutrients including vitamins C, D and E, zinc and selenium and long-chain n-3 fatty acids are important for immune health, but whether these nutrients can be used to treat those already with coronavirus disease discovered in 2019 (COVID-19), particularly if already hospitalised, is uncertain from current inconsistent or scant evidence. There is gut dysbiosis in patients with COVID-19 and studies with probiotics report clinical improvements in such patients. There is an inverse association between adherence to a healthy diet and risk of SARS-CoV-2 infection and hospitalisation with COVID-19 which is consistent with the effects of individual nutrients and other dietary components. Addressing frailty, obesity and micronutrient insufficiency will be important to reduce the burden of future pandemics and nutritional considerations need to be a central part of the approach to preventing infections, optimising vaccine responses and promoting recovery from infection.

Type 2 diabetes mellitus (T2DM) is one of the leading causes of death worldwide. Genetic factors, some underlying medical conditions, and obesity are risk factors of T2DM. Unlike other risk factors which are non-modifiable, obesity is preventable and usually treatable, and is largely contributed by lifestyle factors. Management of these lifestyle factors may curb the development of T2DM and reduces T2DM prevalence. Dietary vitamins have been recommended as a lifestyle modification intervention to support obesity treatment. Vitamins correlate negatively with body weight, body mass index and body composition. Some of the vitamins may also have anti-adipogenic, anti-inflammatory and antioxidant effects. However, results from pre-clinical and clinical studies of the effects of vitamins on obesity are inconsistent. A clear understanding of the effects of vitamins on obesity will help determine dietary intervention that is truly effective in preventing and treating obesity as well as obesity-related complications including T2DM. This article reviews existing evidences of the effects of vitamin supplementation on obesity and obesity-related metabolic status.

Declining nutrient densities of crops in the past 50–70 years have been attributed to unsound agricultural practices and plant breeding focus on yield rather than quality. Few studies have quantified the soil and nutritional quality of grains in organic and conventional farms and reported results are scarce and inconsistent. The Rodale Institute's Farming Systems Trial (FST) was established in 1981 to quantify the effects of long-term organic and conventional grain cropping systems and tillage practices. A 2014 study to quantify effects on the nutrient density of oat grains was integrated into three systems within the long-term trial: organic manure-based (MNR), organic legume-based (LEG), and conventional synthetic input-based (CNV), split between tilled (T) and no-till (NT) practices. Oat grains with hulls removed were analyzed for minerals (n = 24), vitamins (n = 24), amino acids (n = 24) and proteins (n = 24), while soil samples to a depth of 10 cm were analyzed for elemental minerals, and total carbon (C), nitrogen (N) and sulfur (S). Organic systems increased six out ten soil minerals whose concentrations were influenced by cropping systems: aluminum (Al), iron (Fe), chromium (Cr), calcium (Ca), barium (B) and strontium (Sr). All essential amino acids were greater in oat grains under LEG systems compared with other systems except lysine, histidine and methionine. Both LEG systems also increased 12 out of 13 non-essential amino acids in oat grains. Total oat N, C and S required for amino acid synthesis tended to be greater in organic systems. Soil N, C and S were highly correlated with total oat amino acids under organic systems compared to CNV. Organic LEG had significantly greater vitamin B1 than MNR and CNV. These results suggest that nutrient concentrations of oat grains were greater in organic systems compared to CNV systems, and the increase could be partially explained by the long-term soil management differences between the systems.

Levodopa-carbidopa intestinal gel infusion (LCIG) is an established therapy for advanced Parkinson disease (PD), resulting in a significant improvement of quality of life. With increased LCIG adoption worldwide, potential complications due to abnormal vitamin absorption or metabolism have been reported in these patients. Neurologists are unfamiliar with vitamins physiology and pathophysiological mechanisms in case of their deficiency. Unfortunately, clinical and laboratory guidelines related to vitamin monitoring and supplementation in the context of treatment with LCIG are not available. We herein summarize the current knowledge on three vitamins that are reduced with LCIG therapy reporting on their physiology, laboratory testing, and clinical impact of their deficiency/excess. In addition, we proposed an opinion-based recommendation for clinicians treating LCIG patients. Patients and caregivers should be informed about the risk of vitamin deficiency. Vitamin B12, homocysteine, and methylmalonic acid (MMA) should be tested before starting LCIG, six months after and once/year thereafter. Vitamin B6 and folate testing is not universally available but it should be considered if homocysteine is elevated but MMA and/or total vitamin B12 are normal. Prophylaxis of vitamin deficiency should be started as soon as LCIG is implemented, possibly even before. Dietary recommendations are enough in most patients although a subgroup of patients is at higher risk and should receive Vitamin B12 regularly and cycles of B6. Finally, once diagnosed a vitamin deficiency should be readily treated and accompanied by clinical and laboratory monitoring. Resistant cases should receive non-oral routes of administration and possibly discontinue LCIG, even temporarily.

Dietary intake modification is important for the treatment of chronic kidney disease (CKD); however, little is known about the association between dietary intake of antioxidant vitamins and kidney function based on gender difference. We examined the relationship of dietary intake of antioxidant vitamins with decreased kidney function according to gender in Japanese subjects. This population-based, cross-sectional study included 936 Japanese participants with the age of 40 years or older. A validated brief self-administered diet history questionnaire was used to measure dietary intakes of vitamin E and its four isoforms, vitamin A and vitamin C. Decreased kidney function was defined as estimated glomerular filtration rate <60 ml/min/1·73 m2. A total of 498 (53·2 %) of the study participants were women. Mean age was 62·4 ± 11·3 years. Overall, 157 subjects met the criteria of decreased kidney function. In the fully adjusted model, a high vitamin E intake is inversely associated with decreased kidney function in women (odds ratio, 0·886; 95 % confidence interval, 0·786–0·998), whereas vitamin E intake was not associated with decreased kidney function (odds ratio, 0·931; 95 % confidence interval, 0·811–1·069) in men. No significant association between dietary intake of vitamins A and C and decreased kidney function was observed in women and men. Higher dietary intake of vitamin E was inversely associated with decreased kidney function in middle-aged and older women, and the result may provide insight into the more tailored dietary approaches to prevent CKD.

The study included two experiments. In the first, 24 lactating Saanen dairy goats received low-energy diet without vitamin supplements. Twelve goats received a daily IV injection of 2,4- thiazolidinedione (TZD), others received saline injection. A week later, 6 goats from each treatment were challenged with intramammary infusion (IMI) of saline (CTRL) or Streptococcus uberis. In the second experiment, 12 Saanen lactating dairy goats received supplemental vitamins to reach NRC recommendation level. Six goats in each group were injected with TZD or saline daily, and 14 d later received Streptococcus uberis IMI in the right half of the udder. The hypotheses were (1) TZD does not affect the level of retinol in blood, and (2) the fatty acid profile is affected by the interaction between mammary infection and TZD in dairy goats. In the first experiment blood samples were collected on d −7, −2, 1, 2, 12 and milk samples were collected on d −8, 1, 4, 7, and 12, both relative to IMI. In the second experiment, blood samples were collected on d −15, 0, 1, and 10 relative to IMI. Milk and serum samples were analyzed for retinol, α-tocopherol and fatty acid profile. Serum retinol and β-carotene concentrations were higher in the second experiment compared to the first. Serum β-carotene and α-tocopherol were greater in TZD than CTRL and there was a TZD × time interaction in the first experiment. In addition, the TZD × time interaction showed that the milk fatty acid were reduced in C16 : 0 while C18 : 3 n3 while total omega 3 fatty acids were increased, as well as with minor effect on preventing a transient increase in α-tocopherol in milk. Overall, the TZD may affect the lipid-soluble vitamins and fatty acid profile, potentially altering immune responses, during mastitis in dairy goats.

Background: Pathophysiological mechanisms that contribute to neurodegeneration in Amyotrophic Lateral Sclerosis (ALS) include oxidative stress and inflammation. We conducted a preliminary study to explore these mechanisms, to discuss their link in ALS, and to determine the feasibility of incorporating this combined analysis into current biomarkers research. Methods: We enrolled 10 ALS patients and 10 controls. We measured the activities of glutathione peroxidase, glutathione reductase, superoxyde dismutase (SOD), and the levels of serum total antioxidant status (TAS), malondialdehyde (MDA), 8-hydroxy-2’-deoxyguanosine (8-OHdG), and glutathione status (e.g. glutathione disulfide, GSSG/reduced glutathione, GSH). We analysed the concentrations of homocysteine, several cytokines, vitamins and metals by standard methods used in routine practice. Results: There was a significant decrease in TAS levels (p=0.027) and increase in 8-OHdG (p=0.014) and MDA (p=0.011) levels in ALS patients. We also observed a significantly higher GSSG/GSH ratio (p=0.022), and IL-6 (p=0.0079) and IL-8 (p=0.009) concentrations in ALS patients. Correlations were found between biological and clinical markers (homosysteine vs. clinical status at diagnosis, p=0.02) and between some biological markers such as IL-6 vs. GSSG/GSH (p=0.045) or SOD activity (p=0.017). Conclusion: We confirmed the systemic alteration of both the redox and the inflammation status in ALS patients, and we observed a link with some clinical parameters. These promising results encourage us to pursue this study with collection of combined oxidative stress and inflammatory markers.

Increased fruit and vegetable consumption has become a health priority in many countries. Therefore, data investigating the influence of different types of fruits and vegetables on serum antioxidant levels would be useful. The objective of the study was to assess the relationship between fruit and vegetable consumption and vitamin serum antioxidant concentrations. Specific fruit and vegetable groups are evaluated. A total of 3521 subjects (1487 men and 2034 women), aged 35–60 years, participating in the SU.VI.MAX cohort were included in this study. Blood samples of participants were analysed for β-carotene, vitamin C and α-tocopherol. Each subject had completed at least six dietary records during the first 2 years of the study. It was found that women had higher mean β-carotene and vitamin C serum concentrations than men, but lower α-tocopherol serum concentrations. Serum β-carotene and vitamin C concentrations were positively correlated with consumption of both fruit and vegetables, as well as with most of the fruit and vegetable groups tested. These relationships persisted after adjustment for confounding factors. Regression analysis showed a linear dose–response relationship. Root vegetables and citrus fruits were particularly associated with β-carotene serum status as were citrus fruits for vitamin C. Fruit and vegetable consumption was either not or weakly associated with α-tocopherol serum concentrations. These results describe antioxidant serum concentrations according to fruit and vegetable consumption in a large sample and support the findings of previous studies involving a more limited number of subjects.

There has been little work conducted over the last 40 years on estimating vitamin requirements of poultry, and so consequently NRC (1994) values are still often quoted as standards. A review of this information indicates many values are estimates, or extrapolated from comparable species, or as with broiler breeders, simply not given. The current concern related to formulating vitamin levels in poultry diets is the assumption that change in genetic potential of layers and meat birds necessitates re-evaluation, and that parameters for assessing needs are now more complex than simple production metrics as used previously. Unfortunately information on maintenance needs for vitamins is lacking, and while there is now information available on vitamin content of eggs, comprehensive details of the vitamin level in poultry meat products is surprising lacking. With unprecedented egg output of modern layer strains, and ever improving feed efficiency in meat birds, vitamin intake per unit of output is continually declining. For layers the estimate is around a 1% yearly decline in vitamin intake per egg produced, while for meat birds there has been a 0.6-0.8% yearly decline per kg body gain. This reduced intake of vitamins is the basis for improved performance in layers and meat birds fed a higher than normal level of vitamins. However, an even more important basis for reevaluating vitamin needs is change in measurement criteria. Many vitamins and especially the fat soluble vitamins accumulate in eggs and meat in proportion to diet inclusion. Development of vitamin enriched designer poultry products therefore dictates elevated feeding levels of vitamins. Co-incidentally, increased levels of vitamin E in poultry products has led to the realization that increased antioxidant capacity of these tissues enhances shelf life and appearance. Of greatest impact in reevaluating diet vitamin specifications has been the effect of these nutrients on bird health and in particular immune response. For example dietary levels of vitamin E far in excess of NRC (1994) requirements have been shown to positively impact immune response in all ages of bird and also the performance of heat-stressed birds. Expectations of ever increasing performance dictate the need for continual reevaluation in determining vitamin levels within diet formulations as detailed in recent publications on optimum vitamin nutrition of poultry to improve health, welfare, performance and the quality of poultry products.

Their higher production performance and feed conversion efficiency make today's chickens more susceptible to heat stress than ever before. The increasing proportion of poultry production in tropical and subtropical regions makes it necessary to reconsider the long-term selection strategy of today's commercial breeding programmes. Also, the importance of the potential use of Naked neck and Frizzle genes is accentuated. Nutritional strategies aimed to alleviate the negative effects of heat stress by maintaining feed intake, electrolytic and water balance or by supplementing micronutrients such as Vitamins and minerals to satisfy the special needs during heat stress have been proven advantageous. To enhance the birds' thermotolerance by early heat conditioning or feed restriction seems to be one of the most promising management methods in enhancing the heat resistance of broiler chickens in the short run.