Tomiko Tsuji

Self-reported rate of eating correlates with body mass index in 18-y-old Japanese women.

OBJECTIVE: To examine associations between rate of eating and macronutrient and dietary fiber intake, and body mass index (BMI).DESIGN: Cross-sectional study.SUBJECTS: A total of 1695 18-y-old female Japanese dietetic students.MEASUREMENTS: Macronutrient intake (protein, carbohydrate, and fat) and dietary fiber intake were assessed over a 1-month period with a validated, self-administered, diet history questionnaire. Body height and weight and rate of eating (according to five categories) were self-reported.RESULTS: Among the nutrients examined, only dietary fiber intake weakly, but significantly, and negatively correlated with BMI in a multiple regression analysis. The rate of eating showed a significant and positive correlation with BMI. The mean BMI was higher by 2.2, 1.5, 1.0, and 0.5 kg/m2 in the ‘very fast’, ‘relatively fast’, ‘medium’, and ‘relatively slow’ groups, respectively, compared with the ‘very slow’ rate of eating group. This correlation remained evident after adjustment for nutrient intake.CONCLUSIONS: Rate of eating showed a significant and positive correlation with BMI, whereas only dietary fiber intake showed a weak correlation with BMI.

Urinary excretion of vitamin B1, B2, B6, niacin, pantothenic acid, folate, and vitamin C correlates with dietary intakes of free-living elderly, female Japanese.

We hypothesized that 24-hour urinary excretion of water-soluble vitamins might correlate with their intake in free-living Japanese elderly females aged 70 to 84 years. We performed a cross-sectional study composed of 37 healthy, elderly, Japanese females living freely. All foods and the corresponding weights consumed for 4 consecutive days were recorded accurately. A 24-hour urine sample was collected on the fourth day, and the urinary content of water-soluble vitamins was measured. The urinary levels of all vitamins, except for B(12) (r = 0.01; P = .936), were correlated positively with the mean intake over the recent 4 days (vitamin B1: r = 0.62; P < .001; vitamin B2: r = 0.57; P < .001; vitamin B6: r = 0.37; P < .005; niacin: r = 0.54; P < .001; niacin equivalents: r = 0.54; P < .001; pantothenic acid: r = 0.59; P < .001; folate: r = 0.55; P = .001; and vitamin C: r = 0.53; P < .001). Mean estimated intakes of water-soluble vitamins calculated using urinary concentrations and recovery rates showed 96% to 107% of their 3-day mean intake, except for vitamin B12 (65%). We conclude that urinary levels of water-soluble vitamins, except for B12, reflected their recent intake in free-living Japanese elderly females and could be used as a measure of their intake during the previous few days both for group means and for individual rankings within a group.

Twenty-four-hour urinary water-soluble vitamin levels correlate with their intakes in free-living Japanese university students

Background/Objectives:We examined the association between 24-h urinary excretion of water-soluble vitamin levels and their intakes in free-living Japanese university students. The design used was cross-sectional study.Subjects/Methods:A total of 216 healthy, free-living male and female Japanese university students aged 18–27 years voluntarily participated in this study, of which 156 students were eligible for this assessment. All foods consumed for 4 consecutive days were recorded accurately by a weighed food record method. A 24-h urine sample was collected on the fourth day, and the urinary levels of water-soluble vitamins were measured.Results:Each urinary water-soluble vitamin level, except for vitamin B12, was correlated positively with its mean intake in the recent 2–4 days (vitamin B1: r=0.42, P<0.001; vitamin B2: r=0.43, P<0.001; vitamin B6: r=0.40, P<0.001; vitamin B12: r=0.06, P=0.493; niacin: r=0.35, P<0.001; niacin equivalents: r=0.33, P<0.001; pantothenic acid: r=0.47, P<0.001; folate: r=0.27, P=0.001; vitamin C: r=0.44, P<0.001). Mean estimated water-soluble vitamin intakes calculated from urinary levels and recovery rates showed 91–101% of their 3-day mean intakes, except for vitamin B12 (61%).Conclusions:These results showed that urinary water-soluble vitamin levels, except for vitamin B12, reflect their recent intakes in free-living Japanese university students, and could be used as a potential biomarker to estimate mean vitamin intake.

Twenty-four-hour urinary water-soluble vitamin levels correlate with their intakes in free-living Japanese schoolchildren

OBJECTIVE To examine the association between 24 h urinary water-soluble vitamin levels and their intakes in free-living Japanese schoolchildren. DESIGN All foods consumed for four consecutive days were recorded accurately by a weighed food record. A single 24 h urine sample was collected on the fourth day, and the urinary levels of water-soluble vitamins were measured. SETTING An elementary school in Inazawa City, Japan. SUBJECTS A total of 114 healthy, free-living, Japanese elementary-school children aged 10-12 years. RESULTS The urinary level of each water-soluble vitamin was correlated positively to its mean intake in the past 2-4 d (vitamin B1: r = 0·42, P < 0·001; vitamin B2: r = 0·43, P < 0·001; vitamin B6: r = 0·49, P < 0·001; niacin: r = 0·32, P < 0·001; niacin equivalents: r = 0·32, P < 0·001; pantothenic acid: r = 0·32, P < 0·001; folic acid: r = 0·27, P < 0·01; vitamin C: r = 0·39, P < 0.001), except for vitamin B12 (r = 0·10, P = NS). Estimated mean intakes of water-soluble vitamins calculated using urinary levels and recovery rates were 97-102 % of their 3 d mean intake, except for vitamin B12 (79 %). CONCLUSIONS The results show that urinary levels of water-soluble vitamins, except for vitamin B12, reflected their recent intakes in free-living Japanese schoolchildren and could be used as a potential biomarker to estimate mean vitamin intake.

Urinary excretion of vitamin B12 depends on urine volume in Japanese female university students and elderly.

Recent studies have shown that urinary excretion of water-soluble vitamins reflects their intake in humans. However, some have reported that physical characteristics and urine volume may affect the amount of vitamin compounds found in urine. We hypothesized that physical characteristics and urine volume could affect urinary excretion of B-group vitamins. Twenty-four-hour urine samples were collected from 186 free-living Japanese women aged 19 to 21 years and 104 free-living Japanese subjects aged 70 to 84 years. Correlations between urinary output of each B-group vitamin and body height, body weight, body mass index, body surface area, urine volume, and urinary creatinine were determined. Only urinary vitamin B(12) was strongly correlated to urine volume in young (r = 0.683, P < .001) and elderly (r = 0.523, P < .001) subjects. To confirm this finding, 20 Japanese adults were orally administered 1.5 mg of cyanocobalamin (500-fold higher daily intake); and correlations between urinary vitamin B(12) and urine volume were determined. The load of cyanocobalamin increased vitamin B(12) content in the urine by only 1.3-fold. Urinary vitamin B(12) was strongly correlated with urine volume on the day before taking, the day of taking, and the day after taking cyanocobalamin (r = 0.745, P < .001; r = 0.897, P < .0001; and r = 0.855, P < .0001, respectively). We conclude that urinary excretion of vitamin B(12) is dependent upon urine volume, but not on intake of vitamin B(12). Physical characteristics and urine volume are less important for B-group vitamins except for vitamin B(12) as biomarker.

Intake and Urinary Amounts of Biotin in Japanese Elementary School Children, College Students, and Elderly Persons

Biotin enzymes such as pyruvate carboxylase and acetyl-CoA carboxylase are involved with the most basic metabolism. Thus, it is very important to monitor the biotin nutritional status for maintaining good health. We examined urinary excretion and the intake of biotin in a Japanese sample population of 60 boys and 36 girls (10-12 y), 37 male and 135 female college students (18-27 y), and 35 female elderly persons (70-84 y) living freely. All food consumed, and the corresponding weighing, for 4 consecutive days were recorded. A 24-hour urine sample was collected on the fourth day, and the urine biotin was measured. The urine biotin at the fourth day was 57.8, 50.9, 81.0, 66.2, and 82.3 nmol/day in boys, girls, male students, female students, and elderly persons, respectively. The average intake of biotin for 4 consecutive days was 35, 31, 28, 26, and 32 μg/day in boys, girls, male students, female students, and elderly persons, respectively.