Efficacy of Vitamin D Supplementation in Physical Performance of Iranian Elite Athletes.

BACKGROUND: There has been no report of the vitamin D status of the professional athletes from Iran to date. This study was performed to evaluate the efficacy of weekly vitamin D supplementation on athletic performance in Iranian athletes expedited to Asian competition in Taipei, China, 2015. METHODS: This study was a randomized controlled clinical trial. Seventy subjects were enrolled in the study. The athletes were randomly divided into two groups: vitamin D supplement (D; received 50,000 IU of vitamin D supplement weekly) and control (P, received a placebo weekly). Duration of the study was 8 weeks. Anthropometric, dietary, athletic performance, and biochemical evaluations were performed for all subjects in the beginning and in the end of the intervention period. RESULTS: A significant rise in circulating 25(OH)D concentration was observed in D group (17.3 ± 16.9 ng/mL, P < 0.001), whereas in P group, there was a statistically significant decrement (-3.1 ± 8.4 ng/mL, P = 0.040). There were no either within- or between-group significant differences in Ergo jump, vertical jump, and agility tests. In strength leg press tests, both groups showed a significant improvement. However, comparisons of changes revealed that the improvement in D group was significantly higher than in P group (P = 0.034). Moreover, in sprint test (one repetition-Max, 1RM), only D group had a significant within-group improvement (P = 0.030). CONCLUSIONS: Weekly supplementation with 50,000 IU vitamin D resulted in nearly 17 ng/mL increment in circulating calcidiol. This increase was associated with significant improvement of power leg press and sprint tests in D-supplemented group.

Effects of non-digestive polymers used in iron encapsulation on calcium and iron apparent absorption in rats fed by infant formula.

Iron deficiency anemia is a common problem of all ages in developed and developing countries. Various strategies are used by governments and industries to solve this problem. One of these strategies is iron fortification. In the present study, novel iron microcapsules were designed without any changes in their effects on other ingredients in infant milk formulas. Resistant starch-pectin-iron and pectin-iron microparticles were added to infant powdered milk models. Furthermore, animal studies were carried out. Fecal iron and calcium were assessed using flame atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy, respectively. Then, apparent iron and calcium absorptions were calculated. Sensory evaluation was carried out on reconstituted powdered milks. Results showed that iron absorption in rats treated by pectin-coated particles was significantly higher than that in controls with no significant effects on calcium absorption. No significant differences were observed in sensory evaluation.

Effects of pomegranate juice consumption on oxidative stress in patients with type 2 diabetes: a single-blind, randomized clinical trial.

Increased free radicals production due to hyperglycemia produces oxidative stress in patients with diabetes. Pomegranate juice (PJ) has antioxidant properties. This study was conducted to determine the effects of PJ consumption in oxidative stress in type 2 diabetic patients. This study was a randomized clinical trial performed on 60, 40-65 years old diabetic patients. The patients were randomly allocated either to PJ consumption group or control. Patients in PJ group consumed 200 ml of PJ daily for six weeks. Sex distribution and the mean age were not different between two groups. After six weeks intervention, oxidized LDL and anti-oxidized LDL antibodies decreased and total serum antioxidant capacity and arylesterase activity of paraoxonase increased significantly in the PJ-treated group compared to the control group. Our data have shown that six weeks supplementation of PJ could have favorable effects on oxidative stress in patients with type 2 diabetes (T2D).

Competitive Protein-binding assay-based Enzyme-immunoassay Method, Compared to High-pressure Liquid Chromatography, Has a Very Lower Diagnostic Value to Detect Vitamin D Deficiency in 9-12 Years Children.

BACKGROUND: The most reliable indicator of Vitamin D status is circulating concentration of 25-hydroxycalciferol (25(OH) D) routinely determined by enzyme-immunoassays (EIA) methods. This study was performed to compare commonly used competitive protein-binding assays (CPBA)-based EIA with the gold standard, high-pressure liquid chromatography (HPLC). METHODS: Concentrations of 25(OH) D in sera from 257 randomly selected school children aged 9-11 years were determined by two methods of CPBA and HPLC. RESULTS: Mean 25(OH) D concentration was 22 ± 18.8 and 21.9 ± 15.6 nmol/L by CPBA and HPLC, respectively. However, mean 25(OH) D concentrations of the two methods became different after excluding undetectable samples (25.1 ± 18.9 vs. 29 ± 14.5 nmol/L, respectively; P = 0.04). Based on predefined Vitamin D deficiency as 25(OH) D < 12.5 nmol/L, CPBA sensitivity and specificity were 44.2% and 60.6%, respectively, compared to HPLC. In receiver operating characteristic curve analysis, the best cut-offs for CPBA was 5.8 nmol/L, which gave 82% sensitivity, but specificity was 17%. CONCLUSIONS: Though CPBA may be used as a screening tool, more reliable methods are needed for diagnostic purposes.

Calcium Intake, Major Dietary Sources and Bone Health Indicators in Iranian Primary School Children.

BACKGROUND: Adequate calcium intake may have a crucial role with regards to prevention of many chronic diseases, including hypertension, hypercholesterolemia, different types of cancer, obesity and osteoporosis. In children, sufficient calcium intake is especially important to support the accelerated growth spurt during the preteen and teenage years and to increase bone mineral mass to lay the foundation for older age. OBJECTIVES: This study aimed to assess daily calcium intake in school-age children to ensure whether they fulfill the FGP dairy serving recommendations, the recommended levels of daily calcium intake and to assess the relationship between dietary calcium intake and major bone health indicators. PATIENTS AND METHODS: A total of 501 Iranian school-age children were randomly selected. Calcium intake was assessed using a semi-quantitative food frequency questionnaire. Bone health indicators were also assessed. RESULTS: Dairy products contributed to 69.3% of the total calcium intake of the children. Daily adequate intake of calcium was achieved by 17.8% of children. Only 29.8% met the Food guide pyramid recommendations for dairy intake. Dietary calcium intake was not significantly correlated with serum calcium and other selected biochemical indicators of bone health. CONCLUSIONS: The need for planning appropriate nutrition strategies for overcoming inadequate calcium intake in school age children in the city of Tehran is inevitable.

Iron-fortified flour: can it induce lipid peroxidation?

This community-based study was conducted to evaluate the effects of iron-fortified bread consumption on certain biomarkers of oxidative stress in an apparently healthy population. Evaluation of food intake, anthropometric and laboratory variables was performed in the beginning and after the 8-month intervention for all participants. There was no significant change in oxidative stress biomarkers in women following 8 months intervention. However, in men, final values of total antioxidant capacity, compared to the initial ones, showed a significant decrease in (p = 0.01) which was accompanied by a significant increase in superoxide dismutase (p = 0.002). It could be concluded that although the short-term period (8 months) of extra iron intake did not show severe effects of lipid per oxidation, significant changes of serum iron and some oxidative stress indices suggested that fortification of flour with iron among non-anemic adults in the long term was not without adverse effects.

Long-term consequences of iron-fortified flour consumption in nonanemic men.

BACKGROUND/AIMS: Despite the advantages of fortifying flour with iron, there are still special concerns regarding the possible adverse effects of the extra iron consumed by nonanemic individuals. This study aimed to investigate the oxidative stress and iron status following 8 and 16 months of consumption of iron-fortified flour in nonanemic men. METHODS: In a before-and-after intervention study, 78 nonanemic apparently healthy 40- to 65-year-old men were randomly selected from Semnan, in the northeast of Iran. Data were collected at three time points. Evaluation of oxidative stress biomarkers as well as the assessment of iron status was performed in all three stages. After baseline data collection, the flour fortification program was started with 30 mg/kg iron as ferrous sulfate. RESULTS: After 16 months, serum iron levels had significantly increased from 102.9 ± 31.5 µg/dl (baseline) to 117.2 ± 29.8 µg/dl (p < 0.001). The mean total antioxidant capacity (1.71 ± 0.10 µM) was significantly lower than that at baseline (1.83 ± 0.17 µM; p < 0.01). Among other oxidative stress biomarkers, only superoxide dismutase and glutathione peroxidase activity increased significantly compared to the beginning of the study (p < 0.001 and p < 0.001, respectively). The results of this study did not show any symptoms of iron overload after 8 and 16 months. CONCLUSIONS: Our data did not support the safety of flour fortification with 30 mg/kg iron as ferrous sulfate as a community-based approach to control iron deficiency in nonanemic healthy men.

Determination of the actual height predictors in Iranian healthy children.

Height measurement is an important part of nutritional assessment especially in children. However, in such cases as hospitalized or certain kinds of malformations or disabilities, height cannot be measured accurately. We aimed to determine appropriate height predictors in Iranian healthy children for further use in disabled and/or hospitalized children. A total of 730 apparently healthy children aged 7-11 years old from both sexes from Tehran, Meshed and Rasht were enrolled in a cross sectional study. Height, demispan (DS), halfspan (HS), arm length (AL) and tibia length (TL) were all measured using a measuring tape. Linear regression models were established between height, DS, HS, AL and TL. For boys AL (R2=0.783) and TL (R2=0.837) and for girls AL (R2=0.720), TL (R2=0.765), HS (R2=0.771) and age (R2=0.775), respectively, entered the linear regression model. When height predictors were evaluated individually for each city, only in Tehran DS also entered the regression model. Concordance of different percentiles of height estimates based on AL with those of actual height proposed this measure as a reliable height proxy for this age group in clinical as well as field practice.