Regular consumption of both vitamin D- and calcium- and vitamin D-fortified yogurt drink is equally accompanied by lowered blood lipoprotein (a) and elevated apoprotein A1 in subjects with type 2 diabetes: a randomized clinical trial.

OBJECTIVE: Cardiovascular disease (CVD) is the major morbidity and cause of death in diabetic subjects. Observational studies have shown the association of low vitamin D status with poor glycemic control, atherogenic lipid profile, and CVD. However, the possible link between circulating 25-hydroxycholecalciferol and apoproteins (Apo A1 and B) and the atherogenic lipoprotein (a) [Lp(a)] has not been documented to date. METHODS: Ninety subjects with type 2 diabetes (T2D) aged 30-60 years from both sexes were randomly allocated to one of the 3 groups to receive 2 bottles a day of either (1) plain doogh (PD; containing 150 mg calcium and no detectable vitamin D/250 mL); (2) vitamin D-fortified doogh (DD; containing 150 mg calcium and 500 IU vitamin D/250 mL); or (3) calcium- and vitamin D-fortified doogh (CDD; containing 250 mg calcium and 500 IU vitamin D/250 mL) for 12 weeks. Anthropometric, dietary, and laboratory assessments, including Apo A1, Apo B, and Lp(a), were done. RESULTS: Improvement of vitamin D status in DD and CDD groups, compared to PD, resulted in a significant increase in Apo A1 (mean changes 0.22 ± 0.38, 0.20 ± 0.27 and 0.01 ± 0.35 g/L, respectively, p = 0.047) and a significant decrease in serum Lp(a) (mean changes -0.08 ± 0.30, -0.08 ± 0.31, and 0.14 ± 0.25 µmol/L, respectively, p = 0.011). There was no significant difference between DD and CDD groups. Serum Apo B did not change significantly in any of the groups. CONCLUSIONS: Significant amelioration of serum Apo A1 and Lp(a) following improvement of vitamin D status in T2D subjects may have preventive implications against long-term diabetic complications, notably CVD. This trial was registered at ClinicalTrials.gov as NTC01229891.

Improvement of vitamin D status resulted in amelioration of biomarkers of systemic inflammation in the subjects with type 2 diabetes.

BACKGROUND: Both vitamin D deficiency and inflammation have been linked to cardiovascular disease, the major cause of death in diabetes. In this study, the effects of daily intake of vitamin D-fortified yoghourt drink (doogh) on systemic inflammatory biomarkers in subjects with type 2 diabetes (T2D) were investigated. SUBJECTS AND METHODS: In this 12-week randomized controlled trial, T2D subjects received either plain doogh (PD; containing 170 mg calcium and no detectable vitamin D/250 mL, n(1) = 50) or vitamin D3-fortified doogh (FD; containing 170 mg calcium and 500 IU/250 mL, n(2) = 50) twice a day. Glycemic status, body fat mass and systemic inflammatory biomarkers including serum highly sensitive C-reactive protein (hsCRP), serum amyloid A (SAA), interleukin(IL)-2, IL-6, IL-10 and tumour necrosis factor (TNF)-α were evaluated at the beginning and after the intervention. Data were expressed as either mean ± SD or median (interquartile range) whenever they had either normal or non-normal distribution, respectively. RESULTS: In the patients receiving the vitamin D fortified drink, compared with those receiving the unfortified drink, a significant increase in serum 25(OH)D was accompanied by significant changes in TNF-α (-57.9 (-264.6) versus +106.3 (683.2), p = 0.044), IL-6 (-6.3 (-69.2), p = 0.002), hsCRP (-0.39 (-1.50) versus +0.8 (1.52), p < 0.001), SAA (-14.2 ± 44.5 versus +5.6 ± 37.5 mg/L, p = 0.022) and IL-10 (+38.7 ± 157.0 versus -51.9 ± 165.2 ng/L, p = 0.013). The between-group differences of hsCRP, SAA and IL-6 changes remained significant even after controlling for changes quantitative insulin check index (p < 0.001, p < 0.001 and p = 0.009, respectively). CONCLUSIONS: Improvement of vitamin D status of T2D subjects resulted in amelioration of the systemic inflammatory markers. This may have preventive implications against cardiovascular disease and other diabetic complications.

High prevalence of vitamin D deficiency in school-age children in Tehran, 2008: a red alert.

OBJECTIVE: To assess the vitamin D status of 9-12-year-old primary-school children in Tehran during autumn and winter 2007-2008. DESIGN: A descriptive cross-sectional study. SETTING: Primary schools of Tehran city, Iran. SUBJECTS: A total of 1111 children aged 9-12 years (573 boys and 538 girls) from sixty primary schools were enrolled in the study. Weight, height, BMI and serum levels of Ca, P, Mg, 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone (iPTH), osteocalcin and bone-specific alkaline phosphatase of all the participants were assessed. Dietary Ca intake was also evaluated using a quantitative FFQ for a subsample of the study population (n 503). Vitamin D sufficiency was defined on the basis of serum levels of 25(OH)D as either ≥37 nmol/l (criterion 1) or ≥50 nmol/l (criterion 2). RESULTS: Daily intake of Ca did not differ significantly between boys and girls (929·6 (sd 436·7) mg and 909·5 (sd 465·5) mg, respectively). However, on the basis of the first criterion, approximately 86 % of the children had vitamin D deficiency, with 38·3 % being severely deficient (25(OH)D < 12·5 nmol/l). According to the second criterion, prevalence of vitamin D deficiency rose to 91·7 %. Prevalence of vitamin D deficiency was higher in girls than in boys by either criterion. Serum levels of 25(OH)D inversely correlated with iPTH (r = -0·154, P < 0·001) and BMI (r = -0·092, P = 0·002) but directly correlated with duration of sun exposure (r = 0·115, P < 0·001). CONCLUSIONS: The high prevalence of vitamin D deficiency among schoolchildren (especially among girls) warrants immediate interventions for proper nutritional support.

Regular consumption of vitamin D-fortified yogurt drink (Doogh) improved endothelial biomarkers in subjects with type 2 diabetes: a randomized double-blind clinical trial.

BACKGROUND: Endothelial dysfunction has been proposed as the underlying cause of diabetic angiopathy that eventually leads to cardiovascular disease, the major cause of death in diabetes. We recently demonstrated the ameliorating effect of regular vitamin D intake on the glycemic status of patients with type 2 diabetes (T2D). In this study, the effects of improvement of vitamin D status on glycemic status, lipid profile and endothelial biomarkers in T2D subjects were investigated. METHODS: Subjects with T2D were randomly allocated to one of the two groups to receive either plain yogurt drink (PYD; containing 170 mg calcium and no vitamin D/250 mL, n1 = 50) or vitamin D3-fortified yogurt drink (FYD; containing 170 mg calcium and 500 IU/250 mL, n2 = 50) twice a day for 12 weeks. Anthropometric measures, glycemic status, lipid profile, body fat mass (FM) and endothelial biomarkers including serum endothelin-1, E-selectin and matrix metalloproteinase (MMP)-9 were evaluated at the beginning and after the 12-week intervention period. RESULTS: The intervention resulted in a significant improvement in fasting glucose, the Quantitative Insulin Check Index (QUICKI), glycated hemoglobin (HbA1c), triacylglycerols, high-density lipoprotein cholesterol (HDL-C), endothelin-1, E-selectin and MMP-9 in FYD compared to PYD (P < 0.05, for all). Interestingly, difference in changes of endothelin-1, E-selectin and MMP-9 concentrations in FYD compared to PYD (-0.35 ± 0.63 versus -0.03 ± 0.55, P = 0.028; -3.8 ± 7.3 versus 0.95 ± 8.3, P = 0.003 and -2.3 ± 3.7 versus 0.44 ± 7.1 ng/mL, respectively, P < 0.05 for all), even after controlling for changes of QUICKI, FM and waist circumference, remained significant for endothelin-1 and MMP-9 (P = 0.009 and P = 0.005, respectively) but disappeared for E-selectin (P = 0.092). On the contrary, after controlling for serum 25(OH)D, the differences disappeared for endothelin-1(P = 0.066) and MMP-9 (P = 0.277) but still remained significant for E-selectin (P = 0.011). CONCLUSIONS: Ameliorated vitamin D status was accompanied by improved glycemic status, lipid profile and endothelial biomarkers in T2D subjects. Our findings suggest both direct and indirect ameliorating effects of vitamin D on the endothelial biomarkers. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01236846.

Regular daily intake of black tea improves oxidative stress biomarkers and decreases serum C-reactive protein levels in type 2 diabetic patients.

BACKGROUND: This study was undertaken to evaluate the possible effects of different daily doses of black tea intake on certain oxidative stress, inflammatory and metabolic biomarkers in patients with type 2 diabetes mellitus (T2DM). METHODS: Forty-six patients with known T2DM were randomly assigned either to the test (n = 23, 57.0 +/- 7.9 years) or the control (n = 23, 55.4 +/- 8.3 years) group. Following a one-week 'run-in' period, the test group received 150, 300, 450 and 600 ml of black tea extract (BTE) during the weeks 1, 2, 3 and 4, respectively. The control group received 150 ml BTE a day throughout the intervention period. Dietary, anthropometric and biochemical assessments were performed at the end of each week. FINDINGS: Serum total antioxidant capacity was enhanced similarly in both test and control groups. However, daily intake of 2 cups of BTE by the test group showed a suppressing effect on serum malondialdehyde. Serum C-reactive protein significantly decreased and glutathione levels increased following the intake of 4 cups (600 ml) of BTE a day. CONCLUSION: Regular intake of BTE had anti-oxidative and anti-inflammatory effects in patients with T2DM. These findings may, to some extent, explain the mechanisms underlying the protective effects of drinking tea against cardiovascular disease.

Selective microbiologic effects of tea extract on certain antibiotics against Escherichia coli in vitro.

OBJECTIVES: This study evaluated the microbiologic effects of black tea, compared to green tea, alone and in conjunction with selected antibiotics against Escherichia coli, the common cause of intestinal and urinary tract infections. DESIGN: This study was an in vitro evaluation of antibacterial effects of tea extracts. METHODS: Black and green tea extracts were analyzed by using high-performance liquid chromatography to compare their major polyphenol profiles. Different concentrations of the extracts or gallic acid (GA), the phenolic compound found with high concentration in the black tea extract, were employed for bacterial sensitivity tests, using pour plate and disc diffusion methods. The latter was used to evaluate the interactions between the extracts and certain anti-E. coli antibiotics. RESULTS: GA in black tea extract and epigallocatechin and epigallocatechin gallate in green tea extract are present in the highest concentrations, respectively. At concentrations of 25 mg/mL, both black and green teas after 5 and 7 hours completely inhibited E. coli growth. GA at concentrations of 5, 10, and 25 microg/mL after 7, 5 and 3 hrs, respectively, inhibited bacterial growth. Both black and green tea extracts had either synergistic or antagonistic effects at different concentrations on selected antibiotics, while GA showed a synergistic effect with all the antibiotics tested in a dose-dependent manner. The effect was more prominent with amikacin and sulfamethoxazole. CONCLUSIONS: The microbiologic effects of both black tea and green tea extracts on certain antibiotics against E. coli may vary, depending on the type of the tea extract (i.e., black vs. green), the amount of the extract, and the antibiotic being used.

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.

Vitamin D Receptor Fok-I polymorphism modulates diabetic host response to vitamin D intake: need for a nutrigenetic approach.

OBJECTIVE: Interpopulation as well as interindividual variations in response to vitamin D intake commonly observed in subjects with type 2 diabetes may be related to genetic makeup. One of the candidate genes potentially responsible for this diversity is vitamin D receptor (VDR). This study aimed to investigate the interactive effect of VDR Fok-I polymorphism and vitamin D intake on diverse aspects of diabetic host response. RESEARCH DESIGN AND METHODS: Glycemic status, lipid profiles, inflammatory biomarkers, and VDR Fok-I genotypes were determined in diabetic subjects (n = 140) who participated in a randomized controlled trial. Participants consumed two 250-mL bottles per day of yogurt drink (doogh) fortified with 500 IU vitamin D/250 mL for 12 weeks. RESULTS: Mean serum 25(OH)D increased by ~30 nmol/L (P < 0.001). The time × intervention effect was significant for 25(OH)D (P = 0.030), HDL (P = 0.011), high-sensitivity C-reactive protein (hsCRP) (P < 0.001), interleukin (IL)-4 (P = 0.008), and IL-6 (P = 0.017) among the genotypic groups. The alleles were defined as ''F'' or ''f'' depending on the absence or presence of the restriction site, respectively. The least increment in 25(OH)D was in ff (23.0 ± 3.8 nmol/L) compared with Ff (31.2 ± 3.4 nmol/L) and FF (35.6 ± 2.7 nmol/L) (P for trend = 0.009), but only the difference between ff and FF was significant (P = 0.023). FF group had the largest decrement of both hsCRP and IL-6 compared with Ff (P < 0.001 and P = 0.038) and ff (P = 0.010 and P = 0.048), respectively. CONCLUSIONS: We concluded that those of VDR ff genotype may be regarded as "low responders" to vitamin D intake in terms of response of circulating 25(OH)D and certain inflammatory biomarkers. A nutrigenetic approach may, therefore, be needed to protect diabetic patients from vitamin D deficiency.

The opposite associations of lycopene and body fat mass with humoral immunity in type 2 diabetes mellitus: a possible role in atherogenesis.

This study examined the possible effects of lycopene at physiological dosage and body fat mass on the humoral immune response in patients with type 2 diabetes mellitus (T2DM). A total of 35 patients with Typ2 diabetes mellitus from both sexes aged 54+/-9 yrs from the Iranian Diabetes Society were introduced into a double blind placebo controlled clinical trial conducted for 2 months. After a 2-week lycopene free diet washout period, patients were allocated to either lycopene supplementation group (10mg/d) (n=16) or placebo age- and sex matched group (n=19) for 8 weeks. Patients were instructed to keep their diets and physical activities as unchanged as possible. Lycopene supplements increased serum lycopene levels (p<0.001). While intake of dietary energy and nutrients did not change in either groups, the ratio of total antioxidant capacity to malondialdehyde increased significantly in the lycopene group (p=0.007). There was an inverse correlation between serum levels of lycopene and those of IgG (r= -0.338, p=0.008). On the contrary, changes of serum levels of lycopene directly correlated with those of IgM (r=0.466, p=0.005). Interestingly, changes of the amount of fat mass correlated directly with those of serum IgG (r=0.415, p=0.044) but inversely with of serum IgM (r= -0.469, p=0.021). While truncal fat might promote adaptive humoral immunity, lycopene probably by inhibiting MDA-LDL formation might attenuate T cell dependent adaptive (pro-atherogenic) humoral immune response. These findings may have preventive implications in long term diabetic complications, notably atherogenesis.