High Dietary Intake Of Vitamin Research Articles

Dietary intake of vitamin D in adults with overweight and obesity

AbstractIntroductionThe aim of the present study is to study in detail the dietary intake of vitamin D in subjects with different BMI in relation to the status of serum vitamin D.Material and MethodsThey have been studied 264 individuals (41.3% were men and 58.9% were women), aged 19 to 60 years. Body weight and height, waist circumference, systolic and diastolic blood pressure were recorded. Body composition was assessed by bioelectrical impedance. Serum 25(OH)D Total, insulin,high-sensitivity C-reactive protein, glucose level and lipids were measured. Nutrition evaluation was performed through a 24-hour recall and FFQ in January-April 2014 and 2015.Results27.2 % of the participants had normal weight, 24.6 % - overweight, 29.2 % - class I obesity, and 18.9 % – class II or III. 33.3 % had vitamin D deficiency, 40.2 % - insufficiency. It was found that the average daily intake of vitamin D for the whole group of subjects was 6.6 mcg/day. (for the women - 5.6 μg/d and for the men - 10.4 μg/d). In BMI-defined groups it was found that daily average daily intakes of vitamin D in subjects with normal BMI were 7.6 mcg / day, in those with overweight was 6.6 mcg / d, and in those with obesity was 6.0 mcg / day. 80.6% of the subjects were found to have daily average daily intakes of vitamin D under the EAR, which determines a high relative share of individuals with a potential risk of vitamin D deficiency. We found significant, mild to moderate correlations between daily average dietary intake of vitamin D and weight, % body fat (% BF); fat mass (FM), visceral fat (in women), muscle and fat-free mass (FFM), and height-adjusted indices : fat mass index (FMI) and fat-free mass index (FFMI), total body water (TBW in kg and %) and with some of metabolic variables (basal insulin and with the chronic inflammation marker - hs-CRP.DiscussionDietary intake of vitamin D is insufficient and correlates with serum vitamin D levels, FM(kg), %FM, visceral fat, FFM, muscle mass and some of metabolic variables. Male sex, higher education, younger than 30 years and normal BMI (up to 25.0 kg/m2) are the factors determining the higher dietary intake of vitamin D. This requires targeted supplementation and additional intake of vitamin D fortified foods to individuals at risk.

Associations between dietary vitamin D, calcium and dairy products intakes and colorectal cancer risk: a case-control study in China

AbstractIntroductionThe effect of dietary vitamin D, calcium and dairy products intake on colorectal cancer risk is controversial. This study aims to investigate the associations between dietary vitamin D, calcium, dairy products intake and colorectal cancer risk among Chinese population.Materials and MethodsDuring July 2010 to December 2018, 2380 incident, first primary, histologically confirmed colorectal cancer cases and 2389 sex and age-matched (5-year interval) controls were recruited. Dietary intake information was collected by face-to-face interviews using a validated food frequency questionnaire. Energy and other nutrient intakes such as dietary calcium were computed on the basis of the 2002 Chinese Food Composition Table, and the dietary vitamin D intake was calculated according to the United States Department of Agriculture Food Composition Database. Unconditional multivariable logistic regression models were used to calculate the odds ratios (ORs) and 95% confidence interval (CI) after adjusting for various confounders, including socio-demographic characteristics, lifestyle factors, BMI, family history of cancer, energy intake and several nutrient intakes.ResultsThe energy-adjusted mean dietary vitamin D, calcium and total dairy products intakes were 5.69μg/d, 406.94mg/d, 4.02g/d for cases and 6.81μg/d, 468.21mg/d, 9.50g/d for controls. Compared with the controls, cases had a lower intake of dietary vitamin D, calcium and total dairy (P < 0.001). A higher intake of dietary vitamin D and calcium was found to be associated with 43% and 51% reduction in colorectal cancer. The ORs of the highest quartile compared with the lowest quartile intake were 0.57 (95% CI: 0.46, 0.70, Ptrend < 0.001) for dietary vitamin D and 0.49 (95% CI: 0.39, 0.61, Ptrend < 0.001) for dietary calcium. We observed a statistically significant inverse association of dairy products intake with colorectal cancer risk. Compared with the lowest tertile, the adjusted ORs for the highest tertile were 0.31 (95% CI: 0.26, 0.38, Ptrend < 0.001) for total dairy. The inverse associations of dietary vitamin D, calcium and dairy products intakes with colorectal cancer risk were observed in both men and women, colon and rectal cancer.ConclusionOur study indicated that higher dietary vitamin D, calcium and dairy products intakes were associated with a lower colorectal cancer risk.

Is a Higher Dietary Intake of Vitamin E Related to Lower Odds of Neuromyelitis Optica Spectrum Disorder?

Vitamin E is a fat-soluble antioxidant which the possible protective effects of it against some diseases including multiple sclerosis is noted previously. The present study investigated the association between dietary vitamin E and odds of Neuromyelitis Optica Spectrum Disorder (NMOSD). Seventy definite NMOSD cases based on 2015 international consensus criteria and 164 controls were enrolled in this case-control study. Project was performed in the only NMOSD specialist clinic in Sina hospital, Tehran, Iran. A validated food frequency questionnaire with 168 items was used to assess dietary habits of participants during the one past year of study attendance and anthropometric and demographic data were collected. Vitamin E consumption was stratified into quartiles. two logistic regression models were applied for analyzing NMOSD odds across vitamin E quartiles. The mean intakes of vitamin E were 11.71 mg/day in control group and 13.17 mg/day in case group and there was no significant difference between two groups (P-value:0.21). The median dietary intakes of vitamin E were 6.06, 8.74, 12.48 and 19.12 mg/day from the first to the fourth quartiles of vitamin E. In the first regression model by adjustment for age and gender, comparing with the first quartile we found a significant 69% (95%CI:0.13-0.75) decreased odds for NMOSD in the second quartile (P-trend:0.65). Additional adjustment for total fat intake, in the second model resulted in 71% (95%CI:0.12-0.70) and 61% (95%CI:0.15-1.00) significant decreased odds of NMOSD in the second and third quartile of vitamin E consumption vs. first quartile, respectively (P-value:0.35). This study proposed a higher intake of vitamin E which is more close to dietary reference intake (DRI) of vitamin E (15mg/day) as a potential preventive factor for NMOSD odds. The present study is the first study in this topic and more studies are needed to prove this results.

Higher intakes of dietary vitamin D, calcium and dairy products are inversely associated with the risk of colorectal cancer: a case-control study in China.

The effects of dietary vitamin D, Ca and dairy products intakes on colorectal cancer risk remain controversial. The present study investigated the association between these dietary intakes and the risk of colorectal cancer in Guangdong, China. From July 2010 to December 2018, 2380 patients with colorectal cancer and 2389 sex- and age-matched controls were recruited. Dietary intake data were collected through face-to-face interviews using a validated FFQ. Unconditional multivariable logistic regression models were used to calculate the OR and 95 % CI after adjusting for various confounders. Higher dietary vitamin D and Ca intakes were associated with 43 and 52 % reductions in colorectal cancer risk, with OR of 0·57 (95 % CI 0·46, 0·70) and 0·48 (95 % CI 0·39, 0·61), respectively, for the highest quartile (v. the lowest quartile) intakes. A statistically significant inverse association was observed between total dairy product intake and colorectal cancer risk, with an adjusted OR of 0·32 (95 % CI 0·27, 0·39) for the highest v. the lowest tertile. Subjects who drank milk had a 48 % lower risk of colorectal cancer than those who did not (OR 0·52, 95 % CI 0·45, 0·59). The inverse associations of dietary vitamin D, Ca, total dairy products and milk intakes with the risk of colorectal cancer were independent of sex and cancer site. Our study supports the protective effects of high dietary vitamin D, Ca and dairy products intakes against colorectal cancer in a Chinese population.

Vitamin C and Vitamin E Mitigate the Risk of Pancreatic Ductal Adenocarcinoma from Meat-Derived Mutagen Exposure in Adults in a Case-Control Study

Previous studies have found that meat-derived mutagens increase, and vitamin C or E decrease, the risk of pancreatic cancer. The aim of this study was to determine whether intake of vitamin C or E modulates the association between meat-derived mutagen exposure and risk of pancreatic cancer. We conducted a case-control study in 1321 patients with pathologically confirmed pancreatic ductal adenocarcinoma (PDAC) and 1061 healthy controls (aged 28-88 y). Cases and controls were frequency-matched by age, sex, and race/ethnicity. Mutagen intake was assessed using a meat preparation questionnaire. Intakes of vitamin C, E, and other dietary components were assessed via a food-frequency questionnaire in a subset of 811 cases and 818 controls. ORs and 95% CIs were estimated in multivariable-adjusted logistic regression models. The risk of PDAC was not associated with meat intake but was associated with consumption of well-done grilled or barbecued chicken (OR: 1.57; 95% CI: 1.18, 2.09; P=0.001). Intake of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline was associated with increased PDAC risk (Ptrend=0.047). Participants in the highest, as compared with the lowest, quintile of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (PhIP) intake experienced a 38% increased risk of PDAC (95% CI: 1.00, 1.90; P=0.048). Intakes of total vitamin C or E from food and supplements or from supplements alone were each inversely associated with PDAC risk. Stratified analyses showed differential associations for PhIP intake and PDAC risk, such that risk increased among individuals with lower intake of vitamin C or E and decreased among those with higher vitamin intake. Significant interactions of dietary vitamin C, dietary vitamin E, and total vitamin E with PhIP intake were detected (Pinteraction=0.023, <0.001, and 0.013, respectively). Consistent with experimental evidence, this study of 811 cases and 818 controls has shown that high intake of dietary vitamin C or E mitigates the risk of PhIP-related PDAC.

Dietary Vitamin E as a Protective Factor for Parkinson's Disease: Clinical and Experimental Evidence.

Effective disease-modifying treatments are an urgent need for Parkinson's disease (PD). A putative successful strategy is to counteract oxidative stress, not only with synthetic compounds, but also with natural agents or dietary choices. Vitamin E, in particular, is a powerful antioxidant, commonly found in vegetables and other components of the diet. In this work, we performed a questionnaire based case-control study on 100 PD patients and 100 healthy controls. The analysis showed that a higher dietary intake of Vitamin E was inversely associated with PD occurrence independently from age and gender (OR = 1.022; 95% CI = 0.999–1.045; p < 0.05), though unrelated to clinical severity. Then, in order to provide a mechanistic explanation for such observation, we tested the effects of Vitamin E and other alimentary antioxidants in vitro, by utilizing the homozygous PTEN-induced kinase 1 knockout (PINK1−/−) mouse model of PD. PINK1−/− mice exhibit peculiar alterations of synaptic plasticity at corticostriatal synapses, consisting in the loss of both long-term potentiation (LTP) and long-term depression (LTD), in the absence of overt neurodegeneration. Chronic administration of Vitamin E (alpha-tocopherol and the water-soluble analog trolox) fully restored corticostriatal synaptic plasticity in PINK1−/− mice, suggestive of a specific protective action. Vitamin E might indeed compensate PINK1 haploinsufficiency and mitochondrial impairment, reverting some central steps of the pathogenic process. Altogether, both clinical and experimental findings suggest that Vitamin E could be a potential, useful agent for PD patients. These data, although preliminary, may encourage future confirmatory trials.

Higher Dietary Intake of Vitamin D Is Associated with Lower Incidence of Diabetic Nephropathy in Japanese Patients with Type 2 Diabetes

Evidence for optimal dietary intake of vitamin D for prevention of diabetic complications is sparse although associations between low vitamin D intake and high incidence of diabetes and vitamin D supplementation and improvement in insulin resistance were reported. We aimed to investigate the relationship between vitamin D intake and the incidence of diabetes complications in Japanese patients with type 2 diabetes aged 40-70 years with HbA1c≥6.5%. The present analysis was conducted as a multicenter prospective study on the incidence of and risk factors for macro- and microvascular complications among 22Japanese patients with type 2 diabetes from outpatient clinics in 59 university and general hospitals in Japan.Analyzed were 1516 responders to a baseline dietary survey assessed by the Food Frequency Questionnaire based on food groups. Primary outcome was the 8-year risk of nephropathy, retinopathy, and cardiovascular disease (CVD). Cox regression analyses estimated hazard ratios (HRs) for dietary intake adjusted for age, gender, body mass index, HbA1c, smoking, energy intake, and other confounders. Mean vitamin D intake in quartiles ranged from 5.4 to 18.7μg/day. After adjusting for confounders, HRs of diabetic nephropathy in the 2nd, 3rd, and 4th quartiles for vitamin D intake compared with the 1st quartile were 0.7 (95% confidence interval 0.4-1.3, p=0.29), 1.2 (0.6-2.2, p=0.61), and 0.33 (0.14-0.79, p=0.01), respectively. There was no significant associations of vitamin D intake with retinopathy and CVD in the 2nd to 4th quartiles relative to the first quartile (retinopathy: 1.2 (0.9-1.6, 0.4), 0.8 (0.5-1.2, p=0.23), and 0.7 (0.5-1.0, p=0.08); CVD: 1.1 (0.7-1.7, p=0.83), 1.2 (0.7-2.0, p=0.62), and 0.7 (0.4-1.3, p=0.22)). Findings suggested that high vitamin D intake was associated with a lower incidence of diabetes nephropathy among Japanese patients with type 2 diabetes. Disclosure C. Horikawa: None. R. Aida: None. S. Tanaka: None. S. Tanaka: None. C. Kamada: None. Y. Yoshimura: None. A. Araki: None. T. Moriya: None. S. Katayama: None. H. Sone: Research Support; Self; Novo Nordisk Inc., Eli Lilly and Company, MSD K.K., Chugai Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Development Center Asia, Pte. Ltd., Daiichi Sankyo Company, Limited, Ono Pharmaceutical Co., Ltd., Kyowa Hakko Kirin Co., Ltd., Sanofi, Kowa Pharmaceuticals America, Inc., Eisai Inc..

Vitamin D Status and Intakes and Their Association With Cognitive Trajectory in a Longitudinal Study of Urban Adults.

Serum 25-hydroxyvitamin D [25(OH)D], and dietary and supplemental vitamin D may influence cognitive outcomes. Sex-, age-, and race-specific associations of vitamin D status and intake with longitudinal change in various cognitive domains were examined in a large sample of ethnically and socioeconomically diverse US urban adults. Two prospective waves of data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study were used. Adults in Baltimore, Maryland, aged 30 to 64 years at baseline (n = 1231 to 1803), were followed for a mean (± standard deviation) of 4.64 ± 0.93 years. Visit 1 occurred between 2004 and 2009; visit 2, between 2009 and 2013; there were 1.5 to 2.0 visits per participant. Cognitive performance was assessed using 11 test scores covering domains of global cognition, attention, learning/memory, executive function, visuospatial/visuoconstruction ability, psychomotor speed, and language/verbal. Serum 25(OH)D, vitamin D intake, and use of supplements containing vitamin D were the key exposures. A consistent relationship was found between vitamin D status (overall) and supplemental intake (older women and black adults), with a slower rate of decline in the domain of verbal fluency. Higher dietary intake of vitamin D was linked to slower rate of decline in verbal memory among younger women, and a slower rate of decline in visual memory/visuoconstructive abilities among white adults. All other associations were inconsistent. Vitamin D status and intakes were inversely related to domain-specific cognitive decline in US urban adults.

Higher dietary intake of vitamin D may influence total cholesterol and carbohydrate profile independent of body composition in men with Chronic Spinal Cord Injury

Study Design: A case-control design.Objectives: To determine the effects of dietary vitamin D intake on insulin sensitivity (Si), glucose effectiveness (Sg), and lipid profile in individuals with spinal cord injury (SCI).Methods: 20 male, paraplegic (T3-L1) with chronic (> one year) motor complete SCI (AIS A or B) were recruited. Three-day dietary records were analyzed for dietary vitamin D (calciferol), and participants were assigned to one of two groups, a high vitamin D intake group and a low vitamin D intake group based on the mid-point of vitamin D frequency distribution. Individuals in both groups were matched based on age, weight, time since injury and level of injury. Sg, Si and lipid profiles were measured of the two groups.Results: The high vitamin D group had an average intake of 5.33 ± 4.14 mcg compared to low vitamin D group, 0.74 ± 0.24 mcg. None of the 20 participants met the recommended guidelines for daily vitamin D intake. The higher vitamin D group had a significantly lower (P = 0.035) total cholesterol (148.00 ± 14.12 mg/dl) than the lower vitamin D group (171.80 ± 36.22 mg/dl). Vitamin D adjusted to total dietary intake was positively correlated to improvement in Si and Sg (P<0.05).Conclusion: The findings suggest that persons with SCI consume much less than the recommended guidelines for daily vitamin D intake. However, a higher dietary intake of vitamin D may influence total cholesterol and carbohydrate profile as demonstrated by a significant decrease in total cholesterol and improvement in glucose homeostasis independent of body composition changes after SCI.

Excessive dietary intake of vitamin A reduces skull bone thickness in mice.

Calvarial thinning and skull bone defects have been reported in infants with hypervitaminosis A. These findings have also been described in humans, mice and zebrafish with loss-of-function mutations in the enzyme CYP26B1 that degrades retinoic acid (RA), the active metabolite of vitamin A, indicating that these effects are indeed caused by too high levels of vitamin A and that evolutionary conserved mechanisms are involved. To explore these mechanisms, we have fed young mice excessive doses of vitamin A for one week and then analyzed the skull bones using micro computed tomography, histomorphometry, histology and immunohistochemistry. In addition, we have examined the effect of RA on gene expression in osteoblasts in vitro. Compared to a standard diet, a high dietary intake of vitamin A resulted in a rapid and significant reduction in calvarial bone density and suture diastasis. The bone formation rate was almost halved. There was also increased staining of tartrate resistant acid phosphatase in osteocytes and an increased perilacunar matrix area, indicating osteocytic osteolysis. Consistent with this, RA induced genes associated with bone degradation in osteoblasts in vitro. Moreover, and in contrast to other known bone resorption stimulators, vitamin A induced osteoclastic bone resorption on the endocranial surfaces.

Poster 61 Higher Dietary Intake of Vitamin D May Influence Cholesterol and Insulin Sensitivity Independent of Body Composition in Men with Chronic Spinal Cord Injury.

Poster 61 Higher Dietary Intake of Vitamin D May Influence Cholesterol and Insulin Sensitivity Independent of Body Composition in Men with Chronic Spinal Cord Injury.

Association between dietary vitamin C intake and risk of esophageal cancer: A dose-response meta-analysis.

While several epidemiological studies have investigated the association between vitamin C and risk of esophageal cancer, the results remain inconsistent. In the present study, a meta-analysis was conducted to assess the impact of dietary vitamin C intake on esophageal cancer risk. Online databases were searched up to March 29, 2015, for studies on the association between dietary vitamin C intake and esophageal cancer risk. Pooled risk ratios (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Dose-response analyses were performed using the method of restricted cubic splines with four knots at percentiles of 5, 35, 65 and 95% of the distribution. Publication bias was estimated using Egger's tests and funnel plots. In all, 15 articles were included in this meta-analysis, including 20 studies, containing 7063 controls and 3955 cases of esophageal cancer. By comparing the highest vs. the lowest categories of vitamin C intake, we found that vitamin C was inversely associated with the risk of esophageal cancer [overall OR = 0.58, 95% CI = 0.49-0.68, I(2) = 56%]. A linear dose-response relationship was found. With an increase in dietary vitamin C intake of 50 mg/day, the risk of esophageal cancer statistically decreased by 13% (OR = 0.87, 95% CI = 0.80-0.93, p(linearity) = 0.0002). In conclusion, our analysis suggested that the higher intake of dietary vitamin C might have a protective effect against esophageal cancer.

Vitamin D in Norwegian renal transplant recipients: A longitudinal study with repeated measurements in winter and summer.

Organ transplant recipients (OTR) have an increased risk of non-melanoma skin cancer (NMSC) and are advised to avoid direct sunlight. OTR living in the Nordic countries are especially vulnerable to hypovitaminosis D as vitamin D production in the skin is restricted to the summer months. To investigate constitutional and external factors predicting hypovitaminosis and seasonal variation of vitamin D in renal transplant recipients (RTR) living in the vicinity of Oslo (59(o) N). Ninety-four RTR were included. Interviews covering dietary intake of vitamin D and sun exposure were performed and blood samples were collected in February and August 2013. Results Mean age of patients was 56.8 years and mean graft age 14.5 years. The mean daily total vitamin D intake was 11.8 μg, and the prevalence of hypovitaminosis D (<75 nmol/L) was 67.0% in winter and 56.4% in summer. Sunscreen users had significantly higher 25(OH)D than non-users (p = 0.03). Excluding patients having travelled to southern latitudes during the last three months before blood sampling, no statistical difference was found between winter and summer values of vitamin D (p = 0.60). Being male or having red/light blond hair colour increased vitamin D values significantly from winter to summer. Hypovitaminosis D is relatively frequent in Norwegian RTR but not as frequent as earlier reported in studies of RTR from lower latitudes. Lack of seasonal variation in vitamin D may be explained by sun protective behaviour and high dietary intake of vitamin D among patients in this study.

Dietary vitamin D and risk of heart failure in the Physicians' Health Study

Experimental studies have demonstrated the role of vitamin D in key pathways related to cardiovascular health. While several studies have investigated the impact of vitamin D therapy on outcomes in subjects with prevalent heart failure, limited research exists on the relationship of dietary vitamin D consumption with the risk of heart failure. Thus, we sought to investigate whether dietary vitamin D consumption was associated with a lower risk of incident heart failure in a large prospective cohort of male physicians. We prospectively studied 19,635 males from the Physicians' Health Study. Dietary vitamin D information was obtained from a baseline food frequency questionnaire, and heart failure information was obtained by questionnaire and validated in a subsample. Mean age was 66.4 years. Median dietary vitamin D consumption was 200.4 IU and only 2.3% of the subjects used vitamin D supplements. After an average follow-up of 9.3 years, there were 858 new cases of heart failure identified. Higher intake of dietary vitamin D was not associated with incident heart failure in a multivariable adjusted model: hazard ratios (95% CI) of incident heart failure were 1.0 (reference), 1.29 (1.04-1.60), 1.17 (0.94-1.46), 1.22 (0.98-1.53), and 1.16 (0.92-1.46) from lowest to highest age- and energy-adjusted vitamin D quintile, respectively, after adjusting for age, BMI, race, exercise, alcohol use, smoking, calories, and prevalent atrial fibrillation (p for linear trend=0.64). These data are consistent with a lack of an association between dietary vitamin D and incident heart failure in this population of professionally-employed middle-aged males.

Habitual dietary intake of β-carotene, vitamin C, folate, or vitamin E may interact with single nucleotide polymorphisms on brachial-ankle pulse wave velocity in healthy adults.

The interaction between genetics and diet may explain the present disagreement in the protective role of vitamin intake on cardiovascular disease. We cross-sectionally assessed the interaction of habitual dietary intake of β-carotene, vitamin C, folate, and vitamin E with single nucleotide polymorphisms (SNPs) on brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness. Dietary intakes of β-carotene, vitamin C, folate, and vitamin E were quantified by a food frequency questionnaire in 3198 healthy men and women (≥ 40 years) from the Korea Multi-Rural communities Cohort study. baPWV was measured, and 19 SNPs were genotyped. The associations and interactions between dietary vitamin intake, SNP genotype, and baPWV were assessed using general linear models. In both men and women, dietary intake of β-carotene, vitamin C, folate, or vitamin E and baPWV were not directly associated. Vitamin C, folate, and vitamin E intake had an interaction with rs4961 (ADD1) genotype on baPWV in men. rs4961 also interacted with folate intake on baPWV in women. In women, rs10817542 (ZNF618) and rs719856 (CD2AP) had an interaction with β-carotene and folate intake and rs5443 (GNB3) had an interaction with vitamin E intake on baPWV. In general, minor allele homozygotes with low vitamin intake had higher baPWV than other subgroups. Results were similar when supplement users were excluded. Higher intake of dietary vitamin C, folate, and vitamin E may be related to high baPWV in healthy Korean men who are minor allele homozygotes of rs4961. In healthy Korean women, dietary folate, β-carotene, and vitamin E intake may affect baPWV differently according to rs4961, rs10817542, rs719856, or rs5443 genotype. Greater dietary intake of these nutrients may protect those that are genetically vulnerable to stiffening of the arteries.

Mental health: New horizons in nutrition research and dietetic practice

Mental health: New horizons in nutrition research and dietetic practice

High dietary intake of vitamin C suppresses age-related thymic atrophy and contributes to the maintenance of immune cells in vitamin C-deficient senescence marker protein-30 knockout mice.

Vitamin C (VC) is an essential nutrient for humans and certain other animals. It has antioxidant properties and has been reported to ameliorate oxidative damage to lipids, DNA and proteins. However, the effects of VC on immune function are poorly understood, especially the influence of long-term high-dose VC intake on the number and function of immune cells. In the present study, to evaluate the immune effects of VC, VC-deficient senescence marker protein-30 knockout (SMP30KO) mice were fed a diet containing the recommended level of VC (20 mg/kg per d; 0·02 % VC) or a high level of VC (200 mg/kg per d; 0·2 % VC) for 1 year. The plasma VC concentration of the 0·02 % group was the same as that of age-matched C57BL/6 mice after 1 year of feeding; however, plasma VC concentration and thymus weight were significantly higher in the 0·2 % VC group than in the 0·02 % VC group. The total counts of leucocytes, lymphocytes, granulocytes and monocytes in the peripheral blood, as well as the number of splenocytes and thymocytes, were all significantly higher in the 0·2 % VC group than in the 0·02 % VC group. In addition, the number of naive T cells in peripheral blood lymphocytes, the number of memory T-cell populations in splenocytes, and the number of cluster of differentiation (CD)4⁺CD8⁺ or CD4⁺CD8⁻ or CD4⁻CD8⁺ T cells in thymocytes were all markedly higher in the 0·2 % VC group than in the 0·02 % VC group after 1 year of dietary treatment. These results suggest that a long-term high-dose intake of VC is effective in the maintenance of immune cells, partly through the suppression of age-related thymic involution in VC-deficient SMP30KO mice.

Major American dietary patterns are related to risk of age‐related macular degeneration (810.2)

Objective: We hypothesized that major American dietary patterns and differences in specific nutrient intakes within the context of the patterns are associated with age‐related macular degeneration (AMD) risk.Methods: 8,103 eyes from 4,088 eligible participants were classified into control, early AMD, and advanced AMD. Using 37 food group data collected by a 90‐item food frequency questionnaire, two major dietary patterns, prudent and Western patterns, were identified by factor analysis.Results: For early AMD, the multivariate‐adjusted odds ratio (OR) comparing the highest to lowest quintile of the prudent pattern score was ORE5P=0.74 (95% confidence interval (CI): 0.59‐0.91; Ptrend=0.01), and the OR comparing the highest to lowest quintile of the Western pattern score was ORE5W=1.56 (1.18‐2.06; Ptrend=0.01). For advanced AMD, the ORA5P was 0.38 (0.27‐0.54; Ptrend&lt;0.0001), and the ORA5W was 3.70 (2.31‐5.92; Ptrend&lt;0.0001). Our data also suggested benefit from higher dietary intakes of vitamin C, lutein/zeaxanthin, and beta‐carotene, especially in the context of the Western pattern. In the context of the two major patterns, we did not observe a relationship between intake of vitamin E, zinc, DHA or EPA and AMD risk.Conclusions: This cross‐sectional study indicates that diet plays an important role in the development of AMD and that the risk for AMD can be diminished by eating a prudent diet.Grant Funding Source: Supported by the NIH and the USDA

Association between dietary antioxidant vitamins intake/blood level and risk of gastric cancer

We aimed to systematically evaluate the association between dietary intake/blood levels of antioxidant vitamins (vitamin C, vitamin E, β-carotene, and α-carotene) and gastric cancer risk. Systematic literature searches were conducted until April 2013 in Pubmed and Embase to identify relevant studies. Either a fixed- or a random-effects model was adopted to estimate overall odds ratios (ORs). Dose-response, meta-regression, subgroup, and publication bias analyses were applied. Forty articles were finally included in the present study. Higher dietary intake of vitamin C, vitamin E, β-carotene, and α-carotene was inversely associated with gastric cancer risk (for vitamin C, pooled OR=0.58, 95% CI 0.51-0.65; for vitamin E, pooled OR=0.65, 95% CI 0.57-0.74; for β-carotene, pooled OR=0.59, 95% CI 0.49-0.70; for α-carotene, pooled OR=0.69, 95% CI 0.52-0.93). Subgroup analyses suggested the effects of these antioxidant vitamins were different in gastric cancer subtypes. As indicated by dose-response analysis, a 100 mg/day increment of vitamin C intake conferred an OR of 0.78 (95% CI 0.67-0.90); a 15 mg/day increment of vitamin E intake conferred an OR of 0.79 (95% CI 0.66-0.94); and a 5 mg/day increment in β-carotene intake conferred an OR of 0.80 (95% CI 0.60-1.04). No significant association was observed between blood vitamin C, α-tocopherol, γ- tocopherol, β-carotene and α-carotene levels and gastric cancer risk. In conclusion, dietary intake of vitamin C, vitamin E, β-carotene and α-carotene was inversely associated with gastric cancer risk while no such association was observed for blood levels of these antioxidant vitamins, thus the results should be interpreted cautiously.

Antioxidant nutrients and age-related cognitive decline: a systematic review of population-based cohort studies

To further inform the debate on the possible cognitive benefits of antioxidant nutrients in the elderly, we systematically reviewed available prospective studies while paying a special attention to their methodological quality. This is a systematic review of studies involving major antioxidant nutrients and change in cognitive performance. Abstracts were independently reviewed; studies were selected based on prespecified criteria. Methodological quality of primary studies was assessed using a methodological checklist for cohort studies. Findings were presented using a narrative synthesis and tabulation of results. Eight-hundred and fifty potentially eligible studies were identified; 10 met the inclusion criteria and were retained for data extraction and appraisal. The main supportive evidence came from two studies, both judged to be of high quality: The first observed an accelerated decline in global cognition, attention, and psychomotor speed over 9 years, concomitant to a decrease in plasma selenium levels over the same period; the second study reported a slower rate of global cognitive decline over 3 years in persons in the highest quartile of intake of vitamins C, E, and carotenes. All associations persisted after adjustment for confounding factors. Evidence in favor of beneficial associations of higher dietary intake of vitamin E and flavonoids, as well as higher serum beta carotene levels, came from further studies of only adequate quality. There is a possibility for protective effects of antioxidant nutrients against decline in cognition in older people although the supportive evidence is still limited in number. This association deserves further examination in additional quality investigations.