2 Clinical Trials for Various Conditions
The overall purpose of this study is to determine how variation in the CYP4F2 gene modulates the synthesis of vitamin K-dependent clotting factors. We propose that the CYP4F2\*3 gene variant increases short- and long-term vitamin K concentrations in the liver by reducing the efficiency of vitamin K metabolism. The investigators will study the effect of vitamin K supplementation on two biomarkers of hepatic vitamin K concentration in groups with defined CYP4F2\*3 genotype. Specifically, the investigators will test for an association between our novel biomarkers of long-term (plasma Factor II proteoforms) and short-term (urinary K-Acid catabolites) hepatic vitamin K concentration and CYP4F2\*3 following a 10-day period of vitamin K supplementation in healthy volunteers.
Animal studies have found that vitamin K-dependent proteins matrix Gla protein and osteocalcin beneficially influence lipid and glucose metabolism, respectively. However, this concept has not been tested in humans at risk for dyslipidemia and diabetes risk. Vitamin K supplementation presents an opportunity to test the hypothesized link between the vitamin K-dependent proteins and markers of lipid and glucose metabolism. The investigators will conduct an 8-week vitamin K intervention (to manipulate carboxylation of matrix Gla protein and osteocalcin) and determine its effects on markers of dyslipidemia and diabetes risk. Sixty obese children will be randomly allocated to either the control group receiving placebo or the low-dose (45 mcg/d) or high-dose group (90 mcg/d) receiving vitamin K (menaquinone-7).