Effect of vitamin D3 supplementation on blood pressure in adults: An updated meta-analysis.

BACKGROUND AND AIMS: Previous randomized clinical trials (RCTs) of the effects of vitamin D3 supplementation (VD3S) on blood pressure have generated inconsistent results. We evaluated the effect of VD3S on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in a meta-analysis. DATA SYNTHESIS: Literature searches of PubMed, Scopus, Ovid, and Google scholar for publications in English were conducted up to April 2015. RCTs that assessed the effect of VD3S on SBP and DBP were selected. CONCLUSIONS: A total of 30 RCTs with 41 arms including 4744 participants were included. The mean duration of the studies was 5.6 ± 4.0 months, and doses of VD3S varied between 200 and 12,000 IU/day. VD3S had no effect on SBP (-0.68 mmHg, 95%CI: -2.19 to 0.84), and DBP (-0.57 mmHg, 95%CI: -1.36 to 0.22). Subgroup analysis revealed that daily vitamin D3 therapy at a dose of >800 IU/day for <6 months in subjects ≥50 years old reduced both SBP and DBP (p < 0.001). In addition, VD3S showed hypotensive effects in healthy subjects and hypertensive patients, but a hypertensive effect in overweight and obese subjects. However, after excluding overweight and obese subjects, VD3S significantly reduced SBP and DBP. VD3S in combination with calcium supplementation significantly elevated SBP (3.64 mmHg, 95%CI: 3.15-4.13) and DBP (1.71 mmHg, 95%CI: 1.25-2.18). No evidence of publication bias was found. The effects of VD3S on blood pressure depend on dose of supplementation, treatment regimens, trial duration, and population subgroup. Supplementation may be beneficial at daily doses >800 IU/day for <6 months in subjects ≥50 years old.

Dietary phytochemical index is inversely associated with the occurrence of hypertension in adults: a 3-year follow-up (the Tehran Lipid and Glucose Study).

BACKGROUND/OBJECTIVE: The epidemiological association of phytochemical-rich foods with the risk of hypertension is unclear. This study aimed to determine the association of dietary phytochemical index (PI) with the occurrence of hypertension (HTN) after 3 years of follow-up in Tehranian adults. SUBJECTS/METHODS: This prospective study was conducted on 1546 nonhypertensive subjects, aged 20-70 years. Dietary intake was collected by validated semiquantitative food frequency questionnaire (FFQ). Dietary PI was calculated as (dietary energy derived from phytochemical-rich foods (kcal)/total daily energy intake (kcal)) × 100. Blood pressure was measured at baseline and after 3 years of follow-up and HTN was defined by Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure criteria. The odds of HTN after 3 years in each quartile category of dietary PI were estimated by logistic regression model and adjusted for potential variables. RESULTS: The mean age of participants was 38.0±12.0 years and 43% were male. The mean dietary PI was 29.1±11.8. After 3 years of follow-up, 265 (17.1%) new cases of HTN were identified. No significant changes were observed in the systolic and diastolic blood pressure across quartile categories of dietary PI. After adjustment for confounders, the odds (95% confidence interval) of HTN across quartiles of dietary PI were 1.00, 0.97 (0.62-1.38), 0.69 (0.45-1.07) and 0.52 (0.32-0.84) (P for trend=0.004). CONCLUSIONS: Consumption of phytochemical-rich foods may prevent the development of HTN. Further investigations are, however, recommended.

Effect of zinc supplementation on serum zinc and calcium levels in postmenopausal osteoporotic women in Tabriz, Islamic Republic of Iran.

Research on the zinc status of osteoporotic women is scarce. This randomized, double-blind, placebo-controlled clinical trial assessed the effect of zinc supplementation on serum zinc and calcium levels in postmenopausal osteoporotic women. A sample of 60 women referred to a rheumatology clinic in Tabriz were randomly divided into intervention (220 mg zinc sulfate daily) and placebo groups. Anthropometric indices, dietary intake of zinc and calcium and serum zinc and calcium were assessed at baseline and after 60 days. Mean serum zinc concentrations were markedly lower than the normal range at baseline, but mean serum calcium levels were normal. In the intervention group serum levels were significantly higher after 60 days [120.5 (SD 7.5) versus 70.5 (SD 4.6) micrograms/dL] while serum calcium levels were unchanged [8.6 (SD 0.1) versus 9.1 (SD 0.3) mg/dL]. The placebo group showed no significant changes in zinc or calcium levels. Postmenopausal osteoporotic women may benefit from zinc supplementation.

The association of dietary phytochemical index and cardiometabolic risk factors in adults: Tehran Lipid and Glucose Study.

BACKGROUND: Phytochemicals are natural non-nutritive bioactive compounds found in fruits, vegetables, whole grains, nuts and legumes, as well as other plant foods. In the present study, we assessed the dietary phytochemical index (PI) in relation to cardiometabolic risk factors among Iranian adults. METHODS: This cross-sectional study was conducted within the framework of third phase of Tehran Lipid and Glucose Study 2006-2008. For the present study, 2567 subjects aged 19-70 years (1129 men and 1438 women) were selected randomly. Dietary data were collected using a validated semi-quantitative food frequency questionnaire with 168 food items. The PI was calculated based on daily energy derived from phytochemical-rich foods. The odds ratios of abdominal obesity, impaired fasting glucose, hypertriglyceridaemia, low high-density lipoprotein-cholesterol and hypertension were assessed across PI quartile categories. RESULTS: The mean (SD) age of participants was 39.4 (13.2) years. Participants in the upper quartile of PI were older, and had a lower weight and waist circumference. The mean (SD) of the PI was 17.3 (5.6), 25.5 (6.4), 32.7 (8.3) and 42.8 (10.5) in the first, second, third and fourth quartiles, respectively. Compared with those in the lower quartile of PI, participants in the upper quartiles had a 66% lower risk of abdominal obesity [95% confidence interval (CI) = 0.23-0.51] and a 36% lower risk of hypertriglyceridaemia (95% CI, 0.47-0.86), after adjustment for potential confounders. CONCLUSIONS: Higher intakes of phytochemical-rich foods are associated with a lower risk of abdominal obesity and hypertriglyceridaemia as the main cardiometabolic risk factors.

Effect of zinc supplementation on serum zinc and calcium levels in postmenopausal osteoporotic women in Tabriz, Islamic Republic of Iran

Research on the zinc status of osteoporotic women is scarce. This randomized, double-blind, placebo controlled clinical trial assessed the effect of zinc supplementation on serum zinc and calcium levels in postmenopausal osteoporotic women. A sample of 60 women referred to a rheumatology clinic in Tabriz were randomly divided into intervention [220 mg zinc sulfate daily] and placebo groups. Anthropometric indices, dietary intake of zinc and calcium and serum zinc and calcium were assessed at baseline and after 60 days. Mean serum zinc concentrations were markedly lower than the normal range at baseline, but mean serum calcium levels were normal. In the intervention group serum zinc levels were significantly higher after 60 days [120.5 [SD 7.5] versus 70.5 [SD 4.6] microg/dL] while serum calcium levels were unchanged [8.6 [SD 0.1] versus 9.1 [SD 0.3) mg/dL]. The placebo group showed no significant changes in zinc or calcium levels. Postmenopausal osteoporotic women may benefit from zinc supplementation

Iron, iodine and vitamin a in the middle East; a systematic review of deficiency and food fortification.

BACKGROUND: Micronutrient deficiency is one of the major public health problems in the Middle East affecting economic, political and social development of countries. The three commonest micronutrient deficiencies belong to iron, iodine and vitamin A. METHODS: we conducted a systematic review of published English articles in the Middle East countries using databases from PubMed, World Health Organization and Food and Agriculture Organization from 1985 onward. A total of 6050 articles were identified and after evaluation based on eligibility criteria, 81 articles included in this systematic review. RESULTS: Despite implementation of flour fortification other control strategies, the prevalence of iron deficiency is moderate to severe in the Middle Eastern countries, because of ineffective iron fortification program, food interaction and hemoglobin application as anemia indictors in these countries. Mild to severe iodine deficiency disorders exist in many countries of the Middle East, due to lack of effective iodine supplementation program. The prevalence of vitamin A deficiency is mild to severe and there is lack of vitamin A fortification program in many countries in this region. CONCLUSION: Despite unharmonized efforts to control malnutrition of micronutrients, iron, iodine and vitamin A deficiencies are still exist in some countries of the Middle East. Effective, well controlled and harmonized programs for elimination of micronutrient deficiencies need to be initiated for governments and supported by international organizations in this region.

Association between modifiable lifestyle factors and inflammatory markers in patients with metabolic syndrome.

There is accumulating evidence suggesting that inflammation is the bridging link between cardiovascular disease and metabolic syndrome. Recent studies have shown a relationship between inflammatory markers and modifiable lifestyle factors including fitness, diet, exercise and smoking. We carried out a cross-sectional study of 195 patients with metabolic syndrome. Data on nutritional intake, physical activity level and smoking habits were collected through a questionnaire. Weight and body composition were determined and C-reactive protein and interluekin-6 concentrations were measured. C-reactive protein level had a significant association with body mass index (r = 0.18), adiposity (r = 0.23), smoking (r = 0.20), carbohydrate intake (r = 0.19) and saturated fatty acid (r = 0.20). Interluekin-6 concentration was significantly correlated with dietary carbohydrate (r = 0.15), saturated fatty acid (r = 0.15) and glycaemic load (r = 0.15). No association was observed between physical activity level and inflammatory markers.

Association between modifiable lifestyle factors and inflammatory markers in patients with metabolic syndrome

There is accumulating evidence suggesting that inflammation is the bridging link between cardiovascular disease and metabolic syndrome. Recent studies have shown a relationship between inflammatory markers and modifiable lifestyle factors including fitness, diet, exercise and smoking. We carried out a cross-sectional study of 195 patients with metabolic syndrome. Data on nutritional intake, physical activity level and smoking habits were collected through a questionnaire. Weight and body composition were determined and C-reactive protein and interluekin-6 concentrations were measured. C-reactive protein level had a significant association with body mass index [r = 0.18], adiposity [r = 0.23], smoking [r = 0.20], carbohydrate intake [r = 0.19] and saturated fatty acid [r = 0.20]. Interluekin-6 concentration was significantly correlated with dietary carbohydrate [r = 0.15], saturated fatty acid [r = 0.15] and glycaemic load [r = 0.15]. No association was observed between physical activity level and inflammatory markers