Serum concentration of vitamin A and its relationship with body adiposity, oxidative stress, and cardiovascular risk in women with recommended dietary intake of vitamin A.

INTRODUCTION: Background: evidence indicates a role of vitamin A in the regulation of fat mass influencing obesity and cardiovascular diseases. Material and methods: a cross-sectional study in 200 women, paired by age and by the recommended dietary intake of vitamin A. Subjects were divided into four groups according to body mass index (BMI): 80 eutrophic (E), 40 overweight (OW), 40 class I obesity (OI) and 40 class II obesity (OII). Lipid and glycemic profiles were measured and oxidative stress was evaluated through serum concentrations of uric acid, glutathione peroxidase (GSH-Px), and thiobarbituric acid reactive substances (TBARS). Results: the cutoff points for deficiency of serum retinol and ß-carotene levels were < 1.05 µmol/L and 40 µg/dL, respectively. For the recommended dietary intake of vitamin A it was 700 µg/day. Retinol and ß-carotene deficiency was found in the E group at 5 % and 15 %, respectively, reaching 77.5 % and 82.5 % in the OII group. Conclusions: a correlation was observed between serum concentrations of retinol and ß-carotene and glycemic, lipid, and markers of oxidative stress profiles in the groups studied. It was observed that OI and OII subjects who had retinol and ß-carotene deficiency presented a risk that was 16 and 20.7 times greater, respectively, of having a diagnosis with DM2 as compared to E subjects with adequate concentrations of vitamin A. Increased demand of vitamin A may be related to increased BMI, body adiposity, and oxidative stress even when a recommended intake of vitamin A is reached.

INTRODUCCIÓN: Introducción: la evidencia indica un papel de la vitamina A en la regulación de la masa grasa que influye en la obesidad y las enfermedades cardiovasculares. Material y métodos: estudio transversal con 200 mujeres emparejadas por edad y por la ingesta dietética de vitamina A recomendada. Se dividieron en cuatro grupos según el índice de masa corporal (IMC): 80 eutróficas (E), 40 con sobrepeso (OW), 40 con obesidad de clase I (OI) y 40 con obesidad de clase II (OII). Se midieron los perfiles lipídicos y glucémicos y se evaluó el estrés oxidativo a través de las concentraciones séricas de ácido úrico, glutatión-peroxidasa (GSH-Px) y sustancias reactivas del ácido tiobarbitúrico (TBARS). Resultados: los puntos de corte para la deficiencia de las concentraciones séricas de retinol y caroteno fueron de 1,05 µmol/L y 40 g/dL, respectivamente. Para la ingesta dietética recomendada de vitamina A fue de 700 g/día. Se encontró deficiencia de retinol y caroteno en el grupo E, del 5 % y 15 %, respectivamente, alcanzando un 77,5 % y 82,5 % en el grupo OII. Conclusiones: se observó correlación entre las concentraciones séricas de retinol y caroteno y los perfiles glucémico, lipídico y de marcadores de perfiles de estrés oxidativo en los grupos estudiados. Se observó que los sujetos con OI y OII que tenían deficiencia de retinol y caroteno presentaban un riesgo 16 y 20,7 veces mayor, respectivamente, de ser diagnosticados de DM2 en comparación con los E con concentraciones adecuadas de vitamina A. El aumento de la demanda de vitamina A puede estar relacionado con el aumento del IMC, la adiposidad corporal y el estrés oxidativo, incluso cuando se alcanza la ingesta recomendada de vitamina A.

The risks of ubiquinone and ß-carotene deficiency and metabolic disorders in patients with oral cancer.

BACKGROUND: Cancer development is mediated by oxidative stress and inflammation, which may correlate with metabolic disorders. The aim of this study was to evaluate antioxidant vitamins status and metabolic parameters in patients with oral cancer according to tumor-node-metastasis (TNM) stages. METHODS: A total of 194 patients with oral cancer were enrolled in this study. The patients were stratified for four groups according to cancer stages and that the statistics are comparisons across these groups. The levels of antioxidant vitamins (ubiquinone, ß-carotene, vitamin A and E), metabolic parameters, oxidative stress, antioxidant enzymes activity, and inflammatory markers were measured. RESULTS: More than half of the subjects had high blood pressure, central obesity, hyperglycemia, and hyperlipidemia regardless of TNM stage. With regard to antioxidant vitamins status, 46 and 94% of patients had ß-carotene and ubiquinone deficiency, respectively. Patients in T3 and T4 stages had significantly lower antioxidant enzyme (catalase, p = 0.03) activity and higher inflammatory markers levels (high sensitivity C-reactive protein and interleukin-6, p < 0.01) than patients in the other stages. In addition, the level of ß-carotene was negatively associated with waist circumference, and ubiquinone was positively associated with the level of high-density lipoprotein cholesterol (p < 0.05). Higher ß-carotene and ubiquinone levels were negatively associated with hypertriglyceridemia and the risk of metabolic syndrome (p < 0.05). CONCLUSIONS: A high proportion of patients with oral cancer had ubiquinone or ß-carotene deficiency and metabolic disorders. The level of ubiquinone or ß-carotene was negatively associated with the risk of central obesity, hypertriglyceridemia, and metabolic syndrome. Since patients with oral cancer suffer from high oxidative stress and inflammation (particularly in the T3 and T4 stages), supplementation with antioxidant vitamins such as ubiquinone or ß-carotene could be preferentially applied.

A Case of ß-Carotenemia Misdiagnosed as Jaundice by the Bilirubin Oxidase Method.

Serum bilirubin measurement is necessary to accurately distinguish jaundice from carotenemia. A 59.8-y old Japanese male showed symptoms of yellow skin pigmentation as a result of ß-carotenemia. Diagnostic laboratory results indicated elevated levels of serum muscle enzymes (aspartate aminotransferase, lactate dehydrogenase, and creatine kinase), but normal levels in liver function tests (alanine aminotransferase and direct bilirubin). The laboratory results indicated hypothyroid myopathy. Moreover, although the patient did not show significant abnormalities in liver function tests, the serum level of total bilirubin (TBIL) measured by bilirubin oxidase method was markedly increased beyond the upper limit of normal. Fundamental experiments revealed that the bilirubin oxidase method had a positive interference by ß-carotene. These findings suggested that hyper ß-carotenemia could have caused the falsely elevated serum TBIL levels in the patient.

Vitamin A and marbling attributes: Intramuscular fat hyperplasia effects in cattle.

Twenty Angus steers were fed a diet low in ß-carotene and vitamin A for 10months. Ten steers were supplemented with vitamin A weekly, while the other ten steers did not receive any additional vitamin A. The results demonstrated that the restriction of vitamin A intake increased intramuscular fat (IMF) by 46%. This was a function of the total number of marbling flecks increasing by 22% and the average marbling fleck size increasing by 14%. Vitamin A restriction resulted in marbling flecks that were less branched (22%) and slightly more round (4%) with an increased minor axis length (7%). However, restricting vitamin A did not affect the size of the intramuscular or subcutaneous adipocyte cells or the subcutaneous fat depth. The results suggest that vitamin A affects the amount of marbling and other attributes of the marbling flecks due to hyperplasia rather than hypertrophy. This may explain why vitamin A restriction specifically affects IMF rather than subcutaneous fat deposition.

ß-Carotene Concentration and Its Association with Inflammatory Biomarkers in Spanish Schoolchildren.

AIM: To examine the correlation between inflammatory biomarkers and plasma ß-carotene levels in children. METHODS: A total of 564 Spanish schoolchildren aged 9-12 were observed and studied. Plasma ß-carotene levels were assessed by HPLC. A ß-carotene level <4.83 µg/dL (0.09 µmol/L) was considered deficient. Plasma tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by immunoenzyme assays. Serum high-sensitivity C-reactive protein (hs-CRP) was tested by immunonephelometry. RESULTS: Subjects who were ß-carotene-deficient (23.1% of the studied children) had higher IL-6 levels than subjects with normal ß-carotene concentrations. The log-IL-6 and log-hs-CRP concentrations, but not the log-TNF-α level, were strongly and inversely related to the plasma log-ß-carotene level (taking into account log-age, energy intake, log-triglycerides, gender, log-body mass index, log-ß-carotene intake, energy from lipids and cholesterol as covariables). When the 3 inflammatory biomarkers were introduced into the regression model along with the corresponding covariables, only the log-IL-6 level was related to the plasma log-ß-carotene level (ß = -0.505 ± 0.078; p < 0.001). CONCLUSIONS: Inflammatory status, in particular IL-6 levels, appears to be negatively associated with plasma ß-carotene levels in schoolchildren.

Effects of ß-carotene-enriched dry carrots on ß-carotene status and colostral immunoglobulin in ß-carotene-deficient Japanese Black cows.

Data from 18 ß-carotene-deficient Japanese Black cows were collected to clarify the effects of feeding ß-carotene-enriched dry carrots on ß-carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental ß-carotene from dry carrots was 138 mg/day in the carrot group. Plasma ß-carotene concentrations in the control and carrot groups at parturition were 95 and 120 µg/dL, and feeding dry carrots slightly improved plasma ß-carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG1 , but colostral IgM, IgG2 , ß-carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG1 , IgA and IgM concentrations in cows, but plasma IgG1 concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding ß-carotene-enriched dry carrots is effective to enhance colostral IgA and IgG1 concentrations in ß-carotene-deficient cows.

Micronutrient Deficiencies and Plasmodium vivax Malaria among Children in the Brazilian Amazon.

BACKGROUND: There is a growing body of evidence linking micronutrient deficiencies and malaria incidence arising mostly from P. falciparum endemic areas. We assessed the impact of micronutrient deficiencies on malaria incidence and vice versa in the Brazilian state of Amazonas. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated children <10 years old living in rural communities in the state of Amazonas, Brazil, from May 2010 to May 2011. All children were assessed for sociodemographic, anthropometric and laboratory parameters, including vitamin A, beta-carotene, zinc and iron serum levels at the beginning of the study (May 2010) and one year later (May 2011). Children were followed in between using passive surveillance for detection of symptomatic malaria. Those living in the study area at the completion of the observation period were reassessed for micronutrient levels. Univariate Cox-proportional Hazards models were used to assess whether micronutrient deficiencies had an impact on time to first P. vivax malaria episode. We included 95 children median age 4.8 years (interquartile range [IQR]: 2.3-6.6), mostly males (60.0%) and with high maternal illiteracy (72.6%). Vitamin A deficiencies were found in 36% of children, beta-carotene deficiency in 63%, zinc deficiency in 61% and iron deficiency in 51%. Most children (80%) had at least one intestinal parasite. During follow-up, 16 cases of vivax malaria were diagnosed amongst 13 individuals. Micronutrient deficiencies were not associated with increased malaria incidence: vitamin A deficiency [Hazard ratio (HR): 1.51; P-value: 0.45]; beta-carotene [HR: 0.47; P-value: 0.19]; zinc [HR: 1.41; P-value: 0.57] and iron [HR: 2.31; P-value: 0.16]). Upon reevaluation, children with al least one episode of malaria did not present significant changes in micronutrient levels. CONCLUSION: Micronutrient serum levels were not associated with a higher malaria incidence nor the malaria episode influenced micronutrient levels. Future studies targeting larger populations to assess micronutrients levels in P. vivax endemic areas are warranted in order to validate these results.

Dietary exposure to aflatoxin and micronutrient status among young children from Guinea.

SCOPE: Aflatoxin exposure coincides with micronutrient deficiencies in developing countries. Animal feeding studies have postulated that aflatoxin exposure may be exacerbating micronutrient deficiencies. Evidence available in human subjects is limited and inconsistent. The aim of the study was to investigate the relationship between aflatoxin exposure and micronutrient status among young Guinean children. METHODS AND RESULTS: A total of 305 children (28.8 ± 8.4 months) were recruited at groundnut harvest (rainy season), of which 288 were followed up 6 months later postharvest (dry season). Blood samples were collected at each visit. Aflatoxin-albumin adduct levels were measured by ELISA. Vitamin A, vitamin E and ß-carotene concentrations were measured using HPLC methods. Zinc was measured by atomic absorption spectroscopy. Aflatoxin exposure and micronutrient deficiencies were prevalent in this population and were influenced by season, with levels increasing between harvest and postharvest. At harvest, children in the highest aflatoxin exposure group, compared to the lowest, were 1.98 (95%CI: 1.00, 3.92) and 3.56 (95%CI: 1.13, 11.15) times more likely to be zinc and vitamin A deficient. CONCLUSION: Although children with high aflatoxin exposure levels were more likely to be zinc and vitamin A deficient, further research is necessary to determine a cause and effect relationship.

Effects of a food-based intervention on markers of micronutrient status among Indian women of low socio-economic status.

Intakes of micronutrient-rich foods are low among Indian women of reproductive age. We investigated whether consumption of a food-based micronutrient-rich snack increased markers of blood micronutrient concentrations when compared with a control snack. Non-pregnant women (n 222) aged 14-35 years living in a Mumbai slum were randomised to receive a treatment snack (containing green leafy vegetables, dried fruit and whole milk powder), or a control snack containing foods of low micronutrient content such as wheat flour, potato and tapioca. The snacks were consumed under observation 6 d per week for 12 weeks, compliance was recorded, and blood was collected at 0 and 12 weeks. Food-frequency data were collected at both time points. Compliance (defined as the proportion of women who consumed ≥ 3 snacks/week) was >85 % in both groups. We assessed the effects of group allocation on 12-week nutrient concentrations using ANCOVA models with respective 0-week concentrations, BMI, compliance, standard of living, fruit and green leafy vegetable consumption and use of synthetic nutrients as covariates. The treatment snack significantly increased ß-carotene concentrations (treatment effect: 47·1 nmol/l, 95 % CI 6·5, 87·7). There was no effect of group allocation on concentrations of ferritin, retinol, ascorbate, folate or vitamin B12. The present study shows that locally sourced foods can be made into acceptable snacks that may increase serum ß-carotene concentrations among women of reproductive age. However, no increase in circulating concentrations of the other nutrients measured was observed.

Relationship of serum carotenoid concentrations with allostatic load as a measure of chronic stress among middle-aged adults in the USA.

OBJECTIVE: Chronic stress and repeated physiological attempts at stress adaptation may result in 'fatigue' and suboptimal performance of multiple physiological systems, i.e. allostatic load (AL). Although carotenoids have been linked with individual cardiovascular, metabolic and inflammatory biomarkers, little is known about the relationship of carotenoids with the multi-system biomarker measure of stress, AL. The present study examined the association of serum concentrations of carotenoids with AL among middle-aged adults. DESIGN: Cross-sectional. AL score was calculated based on nine risk-rated indicators (systolic and diastolic blood pressure, pulse rate, total and HDL-cholesterol, glycosylated Hb, sex-specific waist-to-hip ratio, albumin and C-reactive protein). SUBJECTS: Middle-aged (45-64 years, n 3387) men and women participants in the Third National Health and Nutrition Examination Survey, NHANES III (1988-1994). RESULTS: Serum ß-carotene concentration was inversely associated with high AL after adjusting for age, education, race/ethnicity, serum cotinine, alcohol consumption, physical activity and other carotenoids (α-carotene, ß-cryptoxanthin, lycopene, lutein/zeaxanthin). Females in the lowest ß-carotene quartile were 2·94 (95 % CI 1·74, 4·94) times and males 2·90 (95 % CI 1·43, 5·89) times as likely to have high AL, compared with peers in the highest quartile (P for linear trend 0·001 and 0·018 for females and males, respectively). Mean serum ß-carotene concentrations were also inversely associated with the number of 'high-risk' AL components (P for linear trend <0·001 and 0·004 for females and males, respectively). CONCLUSIONS: Our study adds to evidence linking low ß-carotene levels with unfavourable health outcomes.

Combined genetic and nutritional risk models of triple negative breast cancer.

Triple negative breast cancer (TNBC) presents clinical challenges due to unknown etiology, lack of treatment targets, and poor prognosis. We examined combined genetic and nutritional risk models of TNBC in 354 breast cancer cases. We evaluated 18 DNA-repair nonsynonymous single nucleotide polymorphisms (nsSNPs) and dietary/nutritional intakes. Multivariate Adaptive Regression Splines models were used to select nutrients of interest and define cut-off values for logistic regression models. Our results suggest that TNBC was associated with 6 DNA-repair nsSNPs, ERCC4 R415Q (rs1800067), MSH3 R940Q (rs184967), MSH6 G39E (rs1042821), POLD1 R119H (rs1726801), XRCC1 R194W (rs1799782), and XPC A499V (rs2228000) and/or deficiencies in 3 micronutrients (zinc, folate, and ß-carotene). Combined analyses of these 6 nsSNPs and 3 micronutrients showed significant association with TNBC: odds ratios = 2.77 (95% confidence interval = 1.01-7.64) and 10.89 (95% confidence interval = 3.50-33.89) for 2 and at least 3 risk factors, respectively. To the best of our knowledge, this is the first study to suggest that multiple genetic and nutritional factors are associated with TNBC, particularly in combination. Our findings, if validated in larger studies, will have important clinical implication that dietary modulations and/or micronutrient supplementations may prevent or reverse TNBC phenotype, so tumors can be treated with less toxic therapeutic strategies, particularly in genetically susceptible women.

Vitamin D3 and beta-carotene deficiency is associated with risk of esophageal squamous cell carcinoma - results of a case-control study in China.

OBJECTIVE: The aim was to evaluate roles of vitamin D3 (VD3) and beta-carotene (BC) in the development of esophageal squamous cell carcinoma (ESCC) in a high-risk area, Huai'an District, Huai'an City, China. METHODS: 100 new ESCC diagnosed cases from 2007 to 2008 and 200 residency- age-, and sex-matched healthy controls were recruited. Data were collected from questionnaires, including a food frequency questionnaire (FFQ) to calculate the BC intake, and reversed phase high-performance liquid chromatography (RP-HPLC) was used to measure the serum concentrations of BC and VD3. Odds ratios (OR) and 95% confidence intervals (CI) were calculated in conditional logistic regression models. RESULTS: The average dietary intake of BC was 3322.9 µg (2032.4- 5734.3) in the case group and 3626.8 µg (1961.9-5827.9) in control group per capita per day with no significant difference by Wilcoxon test (p>0.05). However, the levels of VD3 and BC in the case group were significantly lower than in the control group (p<0.05). The OR values of the highest quartile and the lowest quartile of VD3 and BC in serum samples were both 0.13. CONCLUSION: Our results add to the evidence that high circulating levels of VD3 and BC are associated with a reduced risk of ESCC in this Chinese population.

Micronutrient deficiency in obese subjects undergoing low calorie diet.

BACKGROUND: The prevalence of micronutrient deficiencies is higher in obese individuals compared to normal-weight people, probably because of inadequate eating habits but also due to increased demands among overweight persons, which are underestimated by dietary reference intakes (DRI) intended for the general population. We therefore evaluated the dietary micronutrient intake in obese individuals compared to a reference population and DRI recommendations. Furthermore, we determined the micronutrient status in obese subjects undergoing a standardized DRI-covering low-calorie formula diet to analyze if the DRI meet the micronutrient requirements of obese individuals. METHODS: In 104 subjects baseline micronutrient intake was determined by dietary record collection. A randomly assigned subgroup of subjects (n = 32) underwent a standardized DRI-covering low-calorie formula diet over a period of three months. Pre- and post-interventional intracellular micronutrient status in buccal mucosa cells (BMC) was analyzed, as well as additional micronutrient serum concentrations in 14 of the subjects. RESULTS: Prior to dietetic intervention, nutrition was calorie-rich and micronutrient-poor. Baseline deficiencies in serum concentrations were observed for 25-hydroxyvitamin-D, vitamin C, selenium, iron, as well as ß-carotene, vitamin C, and lycopene in BMC. After a three-month period of formula diet even more subjects had reduced micronutrient levels of vitamin C (serum, BMC), zinc, and lycopene. There was a significant negative correlation between lipophilic serum vitamin concentrations and body fat, as well as between iron and C-reactive protein. CONCLUSIONS: The present pilot study shows that micronutrient deficiency occurring in obese individuals is not corrected by protein-rich formula diet containing vitamins and minerals according to DRI. In contrast, micronutrient levels remain low or become even lower, which might be explained by insufficient intake, increased demand and unbalanced dispersal of lipophilic compounds in the body. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (NCT01344525). The study protocol comprises only a part of the approved trial protocol.

Comparison of dietary intake between fixed orthodontic patients and control subjects.

BACKGROUND: Adolescence is a period of rapid physiological and psychological development which is associated with an increased demand in nutritional requirements. Orthodontic therapy is also commonly initiated during this phase of life and nutritional intake may also change during treatment. AIMS: To compare the nutrient intakes of adolescents wearing fixed orthodontic appliances and a control group matched for age and gender. METHOD: A total of 180 patients aged between 15 and 17 years participated in this study (90 in the study group and 90 controls). Demographic data were collected by questionnaire and dietary intake was assessed using a 24-hour memory recall and was analysed using Dietplan6 software (Forestfield Software Ltd, UK). Comparisons between groups were assessed by the Independent sample t-test dnd the SPSS was used for statistical analysis. RESULTS: Orthodontic patients consumed a similar number of total calories, protein and carbohydrate (p > 0.05); however, they had a greater intake of total fat, saturated fat, monosaturated fat, polysaturated fat, linolenic fat, linoleic fat and cholesterol and significantly lower intake of fibre, chromium and beta-carotene (p < 0.05) compared with the Control group. The intake of other macro- and micro-nutrients did not differ significantly between groups. CONCLUSIONS: Adolescents receiving orthodontic treatment have an altered dietary intake that can be harmful to their health. As adolescents are at a critical stage of development and dietary intake is of particular importance, it is recommended that targeted nutritional guidance is provided to patients during orthodontic treatment.

beta-Carotene deficiency in cholestatic liver disease of childhood is caused by beta-carotene malabsorption.

BACKGROUND: : Depletion of beta-carotene (b-c) has not been extensively studied in children with chronic cholestatic liver disease. PATIENTS AND METHODS: : We assessed b-c serum concentration in 53 children with cholestatic liver disease: 19 patients operated on for biliary atresia, 12 with Alagille syndrome, and 22 with progressive familial intrahepatic cholestasis. To test b-c absorption, 6 children with chronic cholestasis received a load of 10 mg b-c/kg body weight. RESULTS: : We found decreased b-c concentrations in 45 patients. The absorption of b-c was not detectable in 5 of 6 children studied. CONCLUSIONS: : b-c depletion is a common problem of chronic cholestatic liver disease in childhood that can be attributed to disturbed intestinal absorption.

Lipodystrophy, lipid profile changes, and low serum retinol and carotenoid levels in children and adolescents with acquired immunodeficiency syndrome.

OBJECTIVE: To assess serum retinol and levels of carotenoids in children and adolescents with acquired immunodeficiency syndrome (AIDS) and to correlate low serum retinol and carotenoid levels with the presence of lipodystrophy, lipid profile changes, lipid peroxidation, and insulin resistance. METHODS: A cross-sectional, controlled observational study was carried out with 30 children and adolescents with AIDS (mean age 9.1 y) receiving antiretroviral therapy (median length of treatment 28.4 mo), including 30 uninfected healthy controls matched for age and gender. Clinical and laboratory assessments were performed to determine nutritional status, presence of lipodystrophy, serum concentrations of retinol, beta-carotene, lycopene, lipid profile (high-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerols), lipid peroxidation (thiobarbituric acid-reactive substances), glycemia, and serum insulin (homeostasis model assessment for insulin resistance, cutoff point >3). Statistical analysis was done with chi-square test and Student's t test. RESULTS: Lipodystrophy was observed in 53.3% of patients with AIDS, and dyslipidemia was detected in 60% and 23% of subjects with human immunodeficiency virus and control subjects, respectively (P = 0.004). A higher prevalence of retinol deficiency (60% versus 26.7%, P = 0.009) and beta-carotene deficiency (23.3% versus 3.3%, P = 0.026) was found in the group with human immunodeficiency virus than in the control group. No correlation was found for low retinol and beta-carotene levels, changes in lipid and glucose metabolism, or lipodystrophy in children and adolescents with AIDS. CONCLUSION: Despite the high frequency of dyslipidemia, lipodystrophy, and retinol and beta-carotene deficiencies, it was not possible to demonstrate a correlation of these findings with lipid peroxidation and insulin resistance. More studies are needed to investigate the causes of retinol and beta-carotene deficiencies in this population and the clinical consequences of these findings.

Serum retinol and ß-carotene levels and risk factors for cardiovascular disease in morbid obesity.

OBJECTIVE: to evaluate retinol and ß-carotene serum levels and their relationship with risk factors for cardiovascular disease in individuals with morbid obesity, resident in Rio de Janeiro. METHODOLOGY: blood serum concentrations of retinol and ß-carotene of 189 morbidly obese individuals were assessed. The metabolic syndrome was identified according to the criteria of the National Cholesterol Education Program (NCEP) and World Health Organization (WHO). Lipid profile, insulin resistance, basal insulin, glycemia, blood pressure, and anthropometry and their correlation with retinol and ß-carotene serum levels were evaluated. RESULTS: metabolic syndrome diagnosis was observed in 49.0% of the sample. Within this percentage the levels of ß-carotene were significantly lower when body mass index increased. Serum retinol didn't show this behavior. Serum retinol inadequacy in patients with metabolic syndrome (61.3%), according to WHO criterion, was higher (15.8%) than when the whole sample was considered (12.7%). When metabolic syndrome was diagnosed by NCEP criterion, ß-carotene inadequacy was higher (42.8%) when compared to the total sample (37.5%). There was a significant difference between average ß-carotene values of patients with and without metabolic syndrome (p=0.048) according to the classification of the NCEP. Lower values were found in patients with metabolic syndrome. CONCLUSION: considering the vitamin A contribution in antioxidant protection, especially when risk factors for cardiovascular disease are present, it is suggested that great attention be given to morbidly obese. This could aid in prevention and treatment of cardiovascular disease, which affects a significant part of the population.

Antioxidant vitamin levels in sickle cell disorders.

BACKGROUND: Sickle cell disorder is a haemoglobinopathy prevalent in the Vidharbha region of Maharashtra, central India. With recent evidence of oxidative stress in sickle haemoglobinopathy, a possible deficiency of antioxidant vitamins was suspected. METHODS: We measured plasma vitamin E, vitamin C and beta-carotene levels in persons with heterozygous (n=80) and homozygous sickle cell state (n=20), and suitable healthy controls for these groups (n=100 and 66, respectively) in a community-based study in the villages near our institution. RESULTS: Subjects with heterozygous sickle cell trait had lower vitamin E levels than their respective controls (p < 0.05). Subjects with homozygous sickle cell disease had lower levels of all three vitamins (p < 0.05). Vitamins E and C levels showed a significant positive correlation in both forms of sickle cell disorder. CONCLUSION: Our findings suggest that there is depletion of the antioxidant vitamins, particularly in severe forms of sickle cell disorder. A trial of administration of therapeutic doses of vitamin E in this condition is warranted.

Relationship between markers of HIV-1 disease progression and serum beta-carotene concentrations in Kenyan women.

Observational studies have suggested that low serum beta-carotene concentrations may influence HIV-1 disease progression. However, randomized trials have not demonstrated beneficial effects of beta-carotene supplementation. To understand this discrepancy, we conducted a cross-sectional study among 400 HIV-1-seropositive women in Mombasa, Kenya, to correlate serum beta-carotene concentrations with several measures of HIV-1 disease severity. beta-Carotene concentrations were significantly associated with biologic markers of HIV-1 disease progression (CD4 count, HIV-1 plasma viral load, serum C-reactive protein [CRP] concentration, and serum albumin level). In multivariate analysis, beta-carotene concentrations below the median were associated with elevated CRP (>10 mg/l, adjusted odds ratio [aOR] 3.32, 95% confidence interval [CI] 1.99-5.53, P<0.001) and higher HIV-1 plasma viral load (for each log(10) copies/mL increase, aOR 1.38, 95% CI 1.01-1.88, P=0.04). In the context of negative findings from randomized trials of beta-carotene supplementation in HIV-1-seropositive individuals, these results suggest that low beta-carotene concentrations primarily reflect more active HIV-1 infection rather than a deficiency amenable to intervention.

Dietary modulation of lens zeaxanthin in quail.

Although higher dietary intake of lutein/zeaxanthin has been associated with reduced risk for cataracts, the impact of dietary supplements on lens lutein (L) or zeaxanthin (Z) has not been examined. If higher lens carotenoids do reduce risk for cataract, it would be essential to know whether dietary carotenoids can elevate carotenoids in the adult vertebrate lens. In this study, a covey of Japanese quail were hatched and raised 6 months on carotenoid-deficient diet, then switched to deficient diet supplemented with low or high 3R,3R'-zeaxanthin (5 or 35 mgkg(-1) food) or beta-carotene (50 mgkg(-1) food). Controls included a group of covey-mates that remained on the deficient diet and another raised from birth on the high Z (35 mg Zkg(-1)) diet. At 1 year of age, carotenoids and tocopherols in the lens and in the serum were analysed by HPLC, and compared by analysis of variance. Serum Z was significantly elevated in deficient birds fed the lower or higher Z supplement for 6 months (P<0.0001 for each). Serum Z in birds maintained on the higher Z supplement for 1 year was much higher than that in deficient birds (P<0.0001), but not different from deficient birds given the higher Z supplement. As in humans, the predominant lens carotenoids were lutein (L) and zeaxanthin (Z), and the total carotenoid concentration was of lower magnitude than the concentration of alpha-tocopherol. Responses to Z supplementation were sex-related. Female quail had 5-10 times higher serum concentrations of both Z and L than males (P<0.0001, <0.001), and they also had higher lens Z concentrations than males (P<0.0006); possible effects of estrogen on lens carotenoids are discussed. Lens Z concentration was strongly and positively correlated with serum Z in females (r=0.77; P<0.002). Deficient adult females supplemented with the 35 mgkg(-1) dose of Z for 6 months had a mean lens Z concentration (0.252+/-0.06 microgg(-1) protein) close to that in females fed with the supplement from birth (0.282+/-0.15 microgg(-1) protein). Birds fed with the higher dietary Z supplement for 6 or 12 months had significantly higher lens Z than birds fed lower or no dietary Z (P<0.0001). Lens L was not altered by dietary supplementation with either Z or beta-carotene. beta-Carotene supplements did not result in detectable lens beta-carotene, and had no effect on lens Z. Neither Z nor beta-carotene supplementation had a significant effect on serum or lens tocopherol concentrations. These studies in quail provide the first experimental evidence that lens carotenoids in adult vertebrates can be manipulated by dietary Z supplements.