Genetic Variants May Affect Vitamin D Concentrations
Genetic variations at three loci appear to increase risk of vitamin D insufficiency
THURSDAY, June 10 (HealthDay News) -- Vitamin D status appears to be affected by variants near genes involved in cholesterol synthesis, hydroxylation and vitamin D transport, with genetic variations at these sites associated with an increased risk of vitamin D insufficiency, according to a study published online June 10 in The Lancet.
In a genome-wide association study, Thomas J. Wang, M.D., of the Massachusetts General Hospital in Boston, and colleagues evaluated 33,996 individuals of European descent from 15 cohorts to identify common genetic variants affecting 25-hydroxyvitamin D concentrations and risk of insufficiency. Concentrations below 75 nmol/L or 50 nmol/L defined vitamin D insufficiency.
The researchers identified variants at three loci (4p12, 11q12 and 11p15) in discovery cohorts that reached genome-wide significance for association with 25-hydroxyvitamin D concentrations. These three loci were confirmed in replication cohorts. In addition, variants at 20q13 and CYP24A1 reached genome-wide significance in the pooled sample. Compared to those in the lowest quartile, individuals with a genotype score in the highest quartile were at a higher risk of having 25-hydroxyvitamin D concentrations lower than 75 nmol/L (odds ratio, 2.47) or 50 nmol/L (odds ratio, 1.92).
"The presence of harmful alleles at the three confirmed loci more than doubled the risk of vitamin D insufficiency," the authors write. "These findings improve our understanding of vitamin D homoeostasis and could assist identification of a subgroup of the white population who are at risk of vitamin D insufficiency."
Several study authors disclosed financial ties to the pharmaceutical industry.