A single gene may determine vitamin D dose response July 2009
Clin Biochem. 2009 Jul;42(10-11):1174-7. Epub 2009 Mar 18.
Common genetic variants of the vitamin D binding protein (DBP) predict differences in response of serum 25-hydroxyvitamin D [25(OH)D] to vitamin D supplementation.
Fu L, Yun F, Oczak M, Wong BY, Vieth R, Cole DE.
Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada M5G 1L5.
BACKGROUND: To determine the effect of vitamin D binding protein (DBP) genotypes on 25-hydroxyvitamin D [25(OH)D] changes with vitamin D supplements, we studied 98 adults receiving 600 or 4000 IU/d vitamin D(3) for one year. 
METHODS: The DBP functional variant, T436K, was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). 
RESULTS: Mean 25(OH)D increases were 97% for TT (n=48), 151% for TK (n=31) and 307% (n=6) for KK genotypes (p=.004). 
CONCLUSIONS: As with baseline 25(OH)D, T436K genotype predicts 25(OH)D changes after long-term vitamin D supplementation.
PMID: 19302999 [PubMed - indexed for MEDLINE]