title: Plasma riboflavin is a useful marker for studying riboflavin requirement in Chinese male adults.
abstract: Urinary riboflavin excretion and erythrocyte glutathione reductase activation coefficient are frequently applied in determining riboflavin requirement. Previously, we found that plasma riboflavin is a sensitive marker in the assessment of riboflavin status in rat models. Here, we hypothesize that plasma riboflavin is a useful maker in studying riboflavin requirement. This study examines the changes of fasting plasma riboflavin and urinary riboflavin excretion in response to different riboflavin intake levels in Chinese male adults. The estimated average requirement (EAR) of riboflavin was extrapolated. Seventy-eight participants were randomly divided into the control and 5 riboflavin-supplemented groups. A 6-week riboflavin supplementation was performed at the doses of 0, 0.2, 0.4, 0.6, 0.8, or 1.0 mg daily. The energy expenditure was 15.4 ± 1.9 MJ/d, as estimated by the 24-hour physical activity recording method. Dietary riboflavin intake was 1.0 ± 0.2 mg/d, based on chemical analysis. The fasting plasma riboflavin was increased significantly in a dose-dependent manner when the supplemented riboflavin exceeded 0.4 mg/d and the EAR of riboflavin was suggested to be between 1.3 and 1.5 mg/d. In addition, we found a significant increase in fasting urinary riboflavin excretion when the supplemented riboflavin exceeded 0.6 mg/d. The critical point was calculated as 1.4 mg/d, based on the intersecting point of the 2 regression lines at lower and higher riboflavin intakes. These findings demonstrate that plasma riboflavin is a sensitive marker for riboflavin status, and the EAR of riboflavin for Chinese male adults is 1.4 mg.
authors.affiliation: Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, No 1, Dali Dao, Tianjin 300050, PR China. Electronic address: guocjtj@126.com.
authors.forename: Changjiang
authors.initials: C
authors.lastname: Guo
authors.affiliation: Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, No 1, Dali Dao, Tianjin 300050, PR China.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, No 1, Dali Dao, Tianjin 300050, PR China.
authors.forename: Weina
authors.initials: W
authors.lastname: Gao
authors.affiliation: Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, No 1, Dali Dao, Tianjin 300050, PR China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Pu
authors.affiliation: Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, No 1, Dali Dao, Tianjin 300050, PR China.
authors.forename: Zhenchuang
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Department of Nutrition, Tianjin Institute of Health and Environmental Medicine, No 1, Dali Dao, Tianjin 300050, PR China.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D001835:Body Weight; D004032:Diet; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism; D004912:Erythrocytes; D015444:Exercise; D005215:Fasting; D006801:Humans; D008297:Male; D015596:Nutrition Assessment; D009751:Nutritional Requirements; D012256:Riboflavin / Q000008:administration & dosage / Q000097:blood* / Q000652:urine; D055815:Young Adult
chemical_list: D012256:Riboflavin
keywords: Estimated average requirement; Plasma; Riboflavin; Urinary excretion