The vitamin D receptor Fok1 polymorphism and bone mineral density in Chinese children

Background: To evaluate the relationship between vitamin D receptor (VDR) gene polymorphism and bone mineral density (BMD) in 213 healthy children aged 6-10 year in China. Methods: A questionnaire survey of dietary pattern. outdoor activity was conducted among 213 children (boys 126, girls 86) randomly selected in Xishui county of Hubei province. The BMD was determined by dual energy X-ray absorptiometry at the distal forearm, calcium. phosphorus, and alkaline phosphatase in serum were immediately analyzed. The Fok1 polymorphism was detected by using PCR-RFLP. Results: BMD was significantly higher in boys than in girls in 8/9 year group. (2) the frequencies of FF, Ff, and ff genotype were 25.8%, 62.0% and 12.2%, respectively; no difference was found between boys and girls. (3) BMD of children carrying FF genotype was higher (0.256 +/- 0.03) than those of carrying Ff genotype (0.241 +/- 0.03), P<0.01; the Ff genotype was associated with lowest forearm BMD in both boys and girls. Outdoor activity also positively affected peak bone mass. Conclusion: The Fok1 polymorphism of the VDR receptor seems to directly affect bone mineral mass in Chinese children. (C) 2008 Elsevier B.V. All rights reserved.