Vitamin K Supplementation Study in Healthy Volunteers (Aim 2B)

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.

The investigators will recruit, by posted advertisements at UWMC, male and female healthy volunteers. A two-step selection process will be employed. Subjects will self-select by responding to flyers, and contact the research coordinator. The research coordinator will screen them for eligibility over the phone and if eligible, make an appointment for the first study visit. For the first phase, the Research Coordinator will collect a buccal swab of DNA from ~ 200 eligible candidates; the DNA will be tested for absence or presence of the CYP4F2*3 variant allele. The PI and Research Coordinator will review the genotyping results and then select 14 individuals with either a homozygous CYP4F2*3 genotype or a heterozygous CYP4F2*1/*3 genotype, and a demographically matched group of 14 with a homozygous CYP4F2*1 genotype at the diagnostic locus for the supplementation phase of the study. The study coordinator will then contact these subjects by phone for Phase II participation.

Procedures - Phase I, Buccal Swab Collection for DNA Isolation.

Demographic Questionnaire: Self-reported heritage, age, and sex will be collected through a brief demographic questionnaire.

Buccal Swab: We will collect cheek cells with a cotton swab and isolate DNA and test for the CYP4F2*1 and CYP4F2*3 alleles.