title: Development of a semi-quantitative food frequency questionnaire for dietary studies--focus on vitamin C intake.
abstract: The present work aimed to provide a basis for examination of intake of selected food items determined with a semi-quantitative food frequency questionnaire (SQFFQ) and planned-food selection (PFS). From February to July of 2003, ninety one cancer patients and 90 matched (same sex and age within 5 years) non-cancer patients were directly interviewed by trained interviewers using the designed questionnaire at the inpatient-department of Viet Duc hospital, Ha Noi City, Viet Nam. Study subjects consumed more SQFFQ-food items than PFS-food items, so that the latter method might not accurately reflect dietary habits regarding estimation of nutrient intake, especially vitamins. Because these are beneficial factors acting against cancer development at many sites, the absence of food items selected by SQFFQ may result in a poor database regarding possible confounding factors. For futher clarification we then focused on vitamin C contributions of Vietnamese food and analyzed data of the National Nutritional Household Survey in 2000: 7,686 households throughout the country (vitamin C intake status) and 158 households with 741 persons of the population of Hanoi city (individual food items contributing to vitamin C). Direct interview using a validated questionnaire with an album of current Vietnamese food items-recipes and weighing checks was conducted to obtain information regarding all types of food intake over the last 24-hours. Contribution analysis using the Nutritive Composition Table of Vietnamese Foods, revision 2000, and stepwise regression analysis was applied. Average intake adjusted by ages of vitamin C per person per day was estimated. In total, the study subjects were found to currently consume 184 food items. Average intake of vitamin C was 72.5 mg per person per day at the national level: 57.9% from leafy vegetables, 33.4% from fresh fruits, and 6.4% from non-leafy vegetables. For vitamin C contribution, the highest 25 food items contributed to a cumulative 95.3% of vitamin C intake with a cumulative R2=0.99.
authors.affiliation: Dept of Occupational Health, Hanoi Medical University, Ton That Tung Street, Hanoi, Viet Nam. letngoan@hmu.edu.vn
authors.forename: Le Tran
authors.initials: le T
authors.lastname: Ngoan
authors.forename: Nguyen Cong
authors.initials: NC
authors.lastname: Khan
authors.forename: Le Bach
authors.initials: le B
authors.lastname: Mai
authors.forename: Nguyen Thi Thanh
authors.initials: NT
authors.lastname: Huong
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Thu
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Lua
authors.forename: Lai Thi Minh
authors.initials: LT
authors.lastname: Hang
authors.forename: Nguyen Ngoc
authors.initials: NN
authors.lastname: Bich
authors.forename: Nguyen Van
authors.initials: NV
authors.lastname: Hieu
authors.forename: Ha Van
authors.initials: HV
authors.lastname: Quyet
authors.forename: Le Thi
authors.initials: le T
authors.lastname: Tai
authors.forename: Do Duc
authors.initials: do D
authors.lastname: Van
authors.forename: Malcolm A
authors.initials: MA
authors.lastname: Moore
authors.forename: Shinkane
authors.initials: S
authors.lastname: Tokudome
authors.forename: Takesumi
authors.initials: T
authors.lastname: Yoshimura
mesh_terms: D001205:Ascorbic Acid / Q000008:administration & dosage*; D016022:Case-Control Studies; D004034:Diet Surveys; D019587:Dietary Supplements; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D005518:Food Preferences; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000178:diet therapy* / Q000453:epidemiology / Q000473:pathology; D009751:Nutritional Requirements; D011336:Probability; D012016:Reference Values; D012042:Registries; D011795:Surveys and Questionnaires; D014744:Vietnam
chemical_list: D001205:Ascorbic Acid