In recent years, reports have described various roles of vitamin D in human health. Vitamin D deficiency has emerged as a significant public health problem throughout the world. Even in the Vietnamese context, it has been reported to be present in a majority of the population in spite of the wide availability of sunlight. Vitamin D and calcium are essential nutrients for bone health. The proposed health benefits of vitamin D and calcium have attracted increased interest from health care professionals, the media, and the public. The aim of this paper is to summarize the published data on vitamin D and calcium intake as well as on the prevalence of vitamin D deficiency in the Vietnamese population, and to provide recommendations for a proper strategy to control calcium and vitamin D deficiency in this population. The national authorities should adopt policies aimed at improving vitamin D and calcium status by using measures such as dietary recommendations, food fortification, vitamin D supplementation, and judicious sun exposure.
Thiochrome, a natural metabolite of thiamine, has scarcely attracted the attention of researchers, since many of them considered it to be a biologically inactive substance. We examined a possible effect of thiochrome upon the reproduction of the organisms of Chlorella, Drosophila, and Danio. We added thiamine or thiochrome to the culture medium or to the aquaria. Our data showed that the number of cells and organisms were increased in the presence of thiamine and thiochrome. We suggest possible effect(s) of thiamine and thiochrome on the reproduction of these organisms.
Dehydroepiandrosterone (DHEA) and its sulfate ester DHEA-sulfate (DHEA-S) are the most abundant adrenal steroids in humans. DHEA has a critical role as a steroidal precursor of androgens and/or estrogens, and in human studies and animal experiments, both DHEA and DHEA-S have multiple beneficial effects. However, there are few reports regarding the relationship between DHEA and nutrient status, especially for vitamins. Therefore, we elucidated the effect of DHEA administration on retinol status. Wistar rats were fed with a standard diet containing 0.4% (wt/wt) DHEA for 2 wk. We assessed retinol status and the expression of retinol-related proteins, including metabolic enzymes, binding proteins, cytochrome P450 (CYP) enzymes, and antioxidant enzymes. Retinol levels in the plasma and the liver of DHEA-fed rats were lower than those of controls. Expression of β-carotene 15,15′-monooxygenase (BCMO) in the liver and intestine of DHEA-fed rats was lower, whereas BCMO expression in the testes of DHEA-fed rats was higher than that of controls. Expression of the retinol-metabolizing aldehyde dehydrogenase (ALDH) enzyme ALDH1A2 was repressed in the liver of DHEA rats, whereas ALDH1A1 expression was unaltered. Hepatic expression of lecithin:retinol acyltransferase (LRAT) and CYP26A1 was lower in DHEA-fed rats than in controls. Retinol status in DHEA-fed rats might be affected by altered BCMO expression in the liver and intestine and hepatic LRAT expression, whereas BCMO expression in peripheral tissues may be regulated in a tissue-specific manner. We have shown that DHEA administration may influence retinol status and the expression of retinol-related proteins.
Biotin is an essential micronutrient, and is a cofactor for several carboxylases that are involved in the metabolism of glucose, fatty acids, and amino acids. Because plant cells can synthesize their own biotin, a wide variety of plant-based foods contains significant amounts of biotin; however, the influence of environmental conditions on the biotin content in plants remains largely unclear. In the present study, we investigated the effects of different cultivation conditions on the biotin content and biotin synthesis in pea sprouts (Pisum sativum). In the experiment, the pea sprouts were removed from their cotyledons and cultivated by hydroponics under five different lighting and temperature conditions (control [25ºC, 12-h light/12-h dark cycle], low light [25ºC, 4-h light/20-h dark cycle], dark [25ºC, 24 h dark], low temperature [12ºC, 12-h light/12-h dark cycle], and cold [6ºC, 12-h light/12-h dark cycle]) for 10 d. Compared to the biotin content of pea sprouts under the control conditions, the biotin contents of pea sprouts under the low-light, dark, and cold conditions had significantly decreased. The dark group showed the lowest biotin content among the groups. Expression of the biotin synthase gene (bio2) was also significantly decreased under the dark and cold conditions compared to the control condition, in a manner similar to that observed for the biotin content. No significant differences in the adenosine triphosphate content were observed among the groups. These results indicate that environmental conditions such as light and temperature modulate the biotin content of pea plant tissues by regulating the expression of biotin synthase.
Folate is a vital vitamin for the human being and its deficiency can lead to a variety of clinical abnormalities ranging from neural tube defects to cancers. Benzo(a)pyrene (BaP), a strong mutagen and carcinogen, is considered one of the common contaminants in food. The aim of this study was to investigate the positive effect of folate on cancer prevention at a fundamental level. In the present study, we investigated the impact of folic acid on BaP-induced mutagenicity and genotoxicity by means of in vitro and in vivo experiments. The reformed Ames test was applied to study the antimutagenicity of folic acid against BaP. The protective effect of folic acid on cytotoxicity caused by BaP in human liver cell line L02 was evaluated by MTT assay. In addition, the effect of folic acid on the BaP-induced genotoxicity in vivo was assessed by mouse bone marrow micronucleus assay. The results indicated that folic acid significantly inhibited the reverse mutation of Salmonella typhimurium strains TA98 and TA100, and protected the viability of human liver cells against BaP (p<0.01). The micronucleus test showed that all doses of folic acid had a remarkable protective effect for the female mice (p<0.01). In conclusion, folic acid was found to reduce the mutagenicity and genotoxicity induced by BaP.
Uncoupling protein 3 (UCP3) and pyruvate dehydrogenase kinase 4 (PDK4) in skeletal muscle are key regulators of the glucose and lipid metabolic processes that are involved in insulin resistance. Medium-chain fatty acids (MCFAs) have anti-obesogenic effects in rodents and humans, while long-chain fatty acids (LCFAs) cause increases in body weight and insulin resistance. To clarify the beneficial effects of MCFAs, we examined UCP3 and PDK4 expression in skeletal muscles of mice fed a MCFA- or LCFA-enriched high-fat diet (HFD). Five-week feeding of the LCFA-enriched HFD caused high body weight gain and induced glucose intolerance in mice, compared with those in mice fed the MCFA-enriched HFD. However, the amounts of UCP3 and PDK4 transcripts in the skeletal muscle of mice fed the MCFA- or LCFA-enriched HFD were similar. To further elucidate the specific effects of MCFAs, such as capric acid (C10:0), on lipid metabolism in skeletal muscles, we examined the effects of various FAs on expression of UCP3 and PDK4, in mouse C2C12 myocytes. Although palmitic acid (C16:0) and lauric acid (C12:0) significantly induced expression of both UCP3 and PDK4, capric acid (C10:0) upregulated only UCP3 expression via activation of peroxisome proliferator-activated receptor-δ. Furthermore, palmitic acid (C16:0) disturbed the insulin-induced phosphorylation of Akt, while MCFAs, including lauric (C12:0), capric (C10:0), and caprylic acid (C12:0), did not. These results suggest that capric acid (C10:0) increases the capacity for fatty acid oxidation without inhibiting glycolysis in skeletal muscle.
Calorie restriction is a common strategy for weight loss and management. Consumption of food and nutrients stimulates diet-induced thermogenesis (DIT), as well as pancreatic and gastrointestinal hormone secretion that may regulate energy metabolism. Yet, little is known about the impact of hypocaloric diets on energy metabolism-related parameters. In this study, we assessed the effects of hypocaloric diets on hormonal variance in relation to DIT in healthy adults. Ten healthy male adults were enrolled in a randomized crossover study comprising three meal trials. Each subject was given a meal of 200 (extremely hypocaloric), 400 (moderately hypocaloric), or 800 kcal (normocaloric). Postprandial blood variables and energy expenditure were measured for 4 h (after the 200- and 400-kcal meals) or 6 h (after the 800-kcal meal). DIT and postprandial changes in blood pancreatic peptide and ghrelin were significantly smaller after the extremely or moderately hypocaloric diet than after the normocaloric diet but were similar between the hypocaloric diets. Postprandial blood insulin, amylin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide type-1 (GLP-1) increased in a calorie-dependent manner. Thermogenic efficiency (DIT per energy intake) was negatively correlated with the maximum blood level (Cmax) (p=0.01) and incremental area under the curve (p=0.01) of the blood GIP response. Calorie restriction thus leads to hormonal responses and lower DIT in healthy adults. Extreme calorie restriction, however, led to greater thermogenic efficiency compared with moderate calorie restriction. The postprandial GIP response may be a good predictor of postprandial thermogenic efficiency.
This study was performed to reveal factors associated with dietary supplement use among Japanese preschool children in a nationwide survey. A cross-sectional, Internet survey was conducted among 2,058 mothers aged 20-40 y old who had preschool children and were registrants of a Japanese social research company in February 2013. The questionnaires assessed dietary supplement use, lifestyle and eating habits in both children and their mothers, eating awareness among mothers and the mothers’ sources of health information. The study employed logistic regression analysis to evaluate the association between dietary supplement use and other variables. Dietary supplements were used by 8.0% of the children. Children who used supplements tended to be older in age, less likely to “get up cheerfully every morning,” more likely to skip breakfast, eat out more frequently, and have mothers who used supplements, than children who did not use supplements. Mothers’ level of education and household income were not associated with supplement use among their children. It is likely that mothers’ anxiety about their children’s health or unhealthy eating habits has a striking effect on supplement use among children. However, the actual dietary balance and daily rhythms of child supplement users were not irregular or unhealthy. It is necessary to give more accurate information on children’s dietary habits and health to address mothers’ anxiety.
Antioxidant therapy has a potential to be introduced as therapeutic modality for chronic obstructive pulmonary disease (COPD) patients. This study aimed to determine the effect of antioxidant supplementation [ascorbic acid and N-Acetylcysteine (NAC)] on nutritional and antioxidant status in male COPD patients. A parallel and single blind randomised controlled clinical trial (RCT) was conducted at two medical centers in Kuala Lumpur, Malaysia. Seventy-nine subjects were recruited and randomly divided into four trial arms (i.e., NAC, vitamin C, NAC+vitamin C and control groups) for six mo. The primary outcome was changes in body mass index by estimating power of 90% and significance level of p<0.05. Repeated Measure ANOVA showed that there was a significant interaction effect on BMI (p=0.046) and carbohydrate intake (p=0.030), especially in the NAC group. Plasma glutathione (GSH) increased significantly in all intervention groups, especially in vitamin C (p=0.005). A single supplementation of NAC or vitamin C improved nutritional and antioxidant status of subjects.
Resistant glucan (RG) is a water-soluble polysaccharide resistant to hydrolysis by digestive enzymes in the human gastrointestinal system. RG mixture (RGM) contains more than 75% RG as dietary fiber and other saccharides. The effects of ingestion of 3.3, 6.6, and 13.2 g/d of RGM (containing of 2.5, 5.0, and 10.0 g/d RG as dietary fiber) on the fecal properties and the frequency of defecation were investigated in 60 female volunteers with constipation. The study was designed as a randomized, single-blinded, and placebo-controlled parallel-group trial. Each subject consumed RGM or a placebo (digestible maltodextrin) for 2 wk. Questionnaire data on the effects on bowel movement were analyzed according to defecation days, defecation frequency, fecal volume, fecal shapes, fecal color, fecal odor, and fecal excretory feeling. The results showed significant increases in defecation frequency (p<0.05), defecation days (p<0.05), and fecal volume (p<0.05) during the 13.2 g/d RGM ingestion period. The effects of RGM on defecation days and frequency showed a dose-dependent increase (p<0.05). These results suggested that the intake of RGM increased defecation days, defecation frequency, and fecal volume. In the gastrointestinal tract, RGM is useful as a water-soluble dietary fiber for the improvement of bowel movements.
Immune milk has been developed as a substitute for colostrum and contains a high concentration of IgG antibodies specific to the immunized pathogens. Meanwhile, bovine herpesvirus type-1 (BHV-1) naturally infects cattle worldwide, and its antibody is found in milk. Moreover, BHV-1 glycoprotein K, the major antigen, exhibits substantial homology with human herpes virus simplex 1 (HSV-1) glycoprotein K. On the basis of this evidence, we hypothesized BHV-1 antibody exists in immune milk and suppresses HSV-1 activity. This study investigated whether immune milk IgG recognizes HSV-1 and suppresses HSV-1 activity. IgG in immune milk was purified by affinity Protein A columns, and HSV-1-reactive IgG in immune milk IgG was detected and quantified by ELISA. The efficacy of the IgG against HSV-1 was analyzed using a reduction assay based on the cytopathic effect due to HSV-1 in the presence of macrophages. We detected a high concentration of HSV-1-reactive IgG in immune milk. Furthermore, IgG suppressed HSV-1 pathogenicity in the presence of macrophages. These results indicate immune milk has protective activity against HSV-1 by opsonic activity owing to its high concentration of HSV-1-reactive IgG, which is likely the BHV-1 antibody. HSV-1 is currently a refractory infection with a worldwide distribution. Primary infection occurs via the oral cavity, but there is no effective precaution at this time. However, the present results suggest that taking oral immune milk may be an effective measure to prevent primary HSV-1 infection in the oral cavity.
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