Vitamin D receptor gene Fok1 polymorphism predicts calcium absorption and bone mineral density in children

J Bone Miner Res. 1999 May;14(5):740-6. doi: 10.1359/jbmr.1999.14.5.740.


The vitamin D receptor (VDR) gene has been implicated as one of the major genetic components of osteoporosis. We evaluated the relationship between markers of mineral status and restriction fragment length polymorphisms of the VDR gene in 72 healthy children age 7-12 years. Using stable isotope techniques and dual-energy X-ray absorptiometry, we measured dietary calcium absorption, bone calcium deposition rates, and total body bone mineral density (BMD). The Fok1 polymorphism at the VDR translation initiation site was significantly associated with BMD (p = 0.02) and calcium absorption (p = 0.04). Children who were FF homozygotes had a mean calcium absorption that was 41.5% greater than those who were ff homozygotes and 17% greater absorption than Ff heterozygotes. BMD was 8.2% greater in the FF genotype than the ff genotype and 4.8% higher than the Ff genotype. These results suggest a substantial relationship between the VDR gene and bone metabolism at one or more levels, including dietary absorption of calcium and BMD in growing children.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Absorptiometry, Photon
  • Absorption
  • Black People / genetics
  • Bone Density / genetics*
  • Bone and Bones / metabolism
  • Calcium / metabolism*
  • Child
  • Female
  • Genotype
  • Humans
  • Male
  • Mexican Americans / genetics
  • Polymorphism, Genetic*
  • Receptors, Calcitriol / genetics*
  • White People / genetics


  • Receptors, Calcitriol
  • Calcium