title: Effects of Fok-I polymorphism in vitamin D receptor gene on serum 25-hydroxyvitamin D, bone-specific alkaline phosphatase and calcaneal quantitative ultrasound parameters in young adults.
abstract: Several genes have been implicated as genetic determinants of osteoporosis. Vitamin D receptor (VDR) is an intracellular hormone receptor that specifically binds to the biologically active form of vitamin D, 1-alpha, 25- dihydroxyvitamin D3 [1, 25(OH)2D], and mediates its effects. One of the most frequently studied single nucleotide polymorphisms is the restriction fragment length polymorphism (RFLP) Fok-I (rs2228570). The presence of a Fok-I site, designated f, allows protein translation to initiate from the first ATG. An allele lacking the site (ATG>ACG: designated F), initiates from a second ATG site. In the present study, we explored the effect of the VDR Fok-I genotype on associations among serum bone-specific alkaline phosphatase (ALP), 25- hydroxyvitamin D3 [25(OH)D], 1, 25(OH)2D, and the dietary nutrient intake in healthy young Japanese subjects (n=193). Dietary nutrient intakes were calculated based on 3-day food records before the day of blood examinations. Quantitative ultrasound (QUS) parameters at the right calcaneus (heel bone) were measured. The allele frequencies were 0.622 for the F allele and 0.378 for the f allele in all subjects. Grouped by the VDR genotype, a significant positive correlation between the levels of serum bone-specific ALP and 25(OH)D was observed in the FF-type (p=0.005), but not in the ff-type. In addition, there was a significant positive correlation between the level of serum 25(OH)D and osteo-sono assessment index (OSI) in the FF-type (p=0.008), but not in the ff-type. These results suggest that the level of circulating 25(OH)D is an important factor when assessing the VDR Fok-I polymorphism to prevent osteoporosis.
authors.affiliation: Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Tanabe
authors.affiliation: Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kawamura
authors.affiliation: Department of Hygienic Sciences, Kobe Pharmaceutical University, Hyogo, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Tsugawa
authors.affiliation: Department of Child Studies, Faculty of Child Studies, Seitoku University, Chiba, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Haraikawa
authors.affiliation: Department of Health and Nutrition Sciences, Faculty of Human Health, Komazawa Women's University, Tokyo, Japan.
authors.forename: Natsuko
authors.initials: N
authors.lastname: Sogabe
authors.affiliation: Department of Hygienic Sciences, Kobe Pharmaceutical University, Hyogo, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Okano
authors.affiliation: Kenkoin Clinic, Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hosoi
authors.affiliation: Department of Food and Nutrition, Faculty of Human Sciences and Design, Japan Women's University, Tokyo, Japan. Email: goseki@fc.jwu.ac.jp.
authors.forename: Masae
authors.initials: M
authors.lastname: Goseki-Sone
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood*; D015519:Bone Density / Q000235:genetics; D001842:Bone and Bones / Q000201:enzymology; D002111:Calcaneus / Q000000981:diagnostic imaging*; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D004032:Diet; D005260:Female; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D009752:Nutritional Status; D010024:Osteoporosis / Q000235:genetics / Q000517:prevention & control; D012150:Polymorphism, Restriction Fragment Length / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D018167:Receptors, Calcitriol / Q000235:genetics*; D014463:Ultrasonography; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D055815:Young Adult
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase; D002117:Calcitriol; D002112:Calcifediol