Background: A pilot study was carried out to evaluate validity and reproducibility of a food frequency questionnaire (FFQ), which was designed to be used in a prospective cohort study in a population at high risk for esophageal cancer in northern Iran. Methods: The FFQ was administered four times to 131 subjects, aged 35-65 years, of both sexes. Twelve 24-h dietary recalls for two consecutive days were administered monthly during 1 year and used as a reference method. The excretion of nitrogen was measured on four 24-h urine samples, and plasma levels of b-carotene, retinol, vitamin C and a-tocopherol was measured from two time points. Relative validity of FFQ and 24-h diet recall was assessed by comparing nutrient intake derived from both methods with the urinary nitrogen and plasma levels of b-carotene, retinol, vitamin C and a-tocopherol. Results: Correlation coefficients comparing energy and nutrients intake based on the mean of the four FFQ and the mean of twelve 24-h diet recalls were 0.75 for total energy, 0.75 for carbohydrates, 0.76 for proteins and 0.65 for fat. Correlation coefficients between the FFQ-based intake and serum levels of b-carotene, retinol, vitamin C and vitamin E/a-tocopherol were 0.37, 0.32, 0.35 and 0.06, respectively. Correlation coefficients between urinary nitrogen and FFQ-based protein intake ranged from 0.23 to 0.35. Intraclass correlation coefficients used to measure reproducibility of FFQ ranged from 0.66 to 0.89. Conclusion: We found that the FFQ provides valid and reliable measurements of habitual intake for energy and most of the nutrients studied.

BackgroundVitamin D concentrations are linked to body composition indices, particularly body fat mass. Relationships between hypovitaminosis D and obesity, described by both BMI and waist circumference, have been mentioned. We have investigated the effect of a 12-week vitamin D3 supplementation on anthropometric indices in healthy overweight and obese women.MethodsIn a double-blind, randomized, placebo-controlled, parallel-group trial, seventy-seven participants (age 38±8.1 years, BMI 29.8±4.1 kg/m2) were randomly allocated into two groups: vitamin D (25 μg per day as cholecalciferol) and placebo (25 μg per day as lactose) for 12 weeks. Body weight, height, waist, hip, fat mass, 25(OH) D, iPTH, and dietary intakes were measured before and after the intervention.ResultsSerum 25(OH)D significantly increased in the vitamin D group compared to the placebo group (38.2±32.7 nmol/L vs. 4.6±14.8 nmol/L; P<0.001) and serum iPTH concentrations were decreased by vitamin D3 supplementation (-0.26±0.57 pmol/L vs. 0.27±0.56 pmol/L; P<0.001). Supplementation with vitamin D3 caused a statistically significant decrease in body fat mass in the vitamin D group compared to the placebo group (-2.7±2.1 kg vs. -0.47±2.1 kg; P<0.001). However, body weight and waist circumference did not change significantly in both groups. A significant reverse correlation between changes in serum 25(OH) D concentrations and body fat mass was observed (r = -0.319, P = 0.005).ConclusionAmong healthy overweight and obese women, increasing 25(OH) D concentrations by vitamin D3 supplementation led to body fat mass reduction.This trial is registered at clinicaltrials.gov as NCT01344161.

Background: Vitamin D concentrations are linked to body composition indices, particularly body fat mass. Relationships between hypovitaminosis D and obesity, described by both BMI and waist circumference, have been mentioned. We have investigated the effect of a 12-week vitamin D3 supplementation on anthropometric indices in healthy overweight and obese women.

Evidence indicates that vitamin D deficiency contributes to CVD. We investigated the effect of vitamin D 3 supplementation on cardiovascular risk factors in women. Healthy premenopausal overweight and obese women (n 77; mean age 38 (SD 8·1) years) were randomly allocated to the vitamin D (25 mg/d as cholecalciferol) or the placebo group in a double-blind manner for 12 weeks. Blood pressure, serum lipoproteins, apolipoproteins and anthropometric parameters were recorded. Dietary intake was recorded using 24 h food recall and FFQ. Physical activity was assessed by the International Physical Activity Questionnaire. Mean total cholesterol concentrations increased in the vitamin D group (0·08 (SD 0·56) mmol/l) but declined in the placebo group (0·47 (SD 0·58) mmol/l), and a significant effect was observed (P#0·001). In the vitamin D group, mean HDL-cholesterol concentration increased, whereas it decreased in the placebo group (0·07 (SD 0·2) v. 20·03 (SD 0·2) mmol/l; P¼ 0·037). Mean apoA-I concentration increased in the vitamin D group, although it decreased in the placebo group (0·04 (SD 0·39) v. 20·25 (SD 0·2) g/l; P# 0·001). Mean LDL-cholesterol:apoB-100 ratio augmented in the vitamin D group, while this ratio declined in the placebo group (0·11 (SD 0·6) v. 2 0·19 (SD 0·3); P¼0·014). Body fat mass was significantly decreased in the vitamin D group more than the placebo group (22·7 (SD 2) v. 20·4 (SD 2) kg; P# 0·001). The findings showed that supplementation with vitamin D 3 can significantly improve HDL-cholesterol, apoA-I concentrations and LDL-cholesterol:apoB-100 ratio, which remained significant in the multivariate model including anthropometric, dietary and physical activity measures. Key words: Vitamin D: CVD: ObesityVitamin D is recognised as the vitamin of sunshine (1) .A relationship between vitamin D and CVD has been proposed by observing more incidence of CVD in winter compared with summer in many countries (2,3) , which might be attributable to the protective effect of vitamin D on CVD (4) .Ecological studies have indicated the higher rate of CHD and high blood pressure increment with more distance from the equator, which is also related to low sun exposure and higher prevalence of vitamin D deficiency (5,6) . It has beenshown that a range of markers including geographic latitude, altitude and season affect vitamin D status which are negatively correlated with cardiovascular morbidity and mortality. Evidence suggests that low levels of vitamin D may contribute to the development of CVD (7) .On the other hand, a range of CVD risk factors including dyslipoproteinaemia, high blood pressure, reduced glucose tolerance, diabetes and increased inflammatory markers are related to obesity, which has been increasing dramatically during recent decades (8 -10) . Serum 25-hydroxyvitamin D (25(OH)D) levels negatively correlate with BMI (11) . It is likely that alteration in vitamin D homeostasis affects CVD development in obese individuals (12)