This one year study of the K vitamers phylloquinone (K1) and menatetranone (MK4) will study
supplementation effects on bone turnover and bone density. Women at least 5 years
postmenopause with normal bone density who do not use estrogen therapy or the following
medications may be eligible:
alendronate (Fosamax), risedronate (Actonel), pamidronate (Aredia), etidronate (Didronel),
zoledronate (Zometa), teriparatide (Forteo), raloxifene (Evista), tamoxifene, warfarin
(Coumadin), anti-seizure medications, prednisone, or oral steroids. Eligible subjects will
take calcium and vitamin D (Citracal) twice a day for the first two months and through-out
the study. After the first two months, subjects are randomized to the K1, MK4 or placebo
groups. Return visits occur at 1, 3, 6 and 12 months. Fasting blood and urine is collected
at each visit and bone density is performed at 3 study visits.
- Female, 5 years postmenopause.
- Community dwelling.
- Able to ingest calcium and vitamin D supplements.
- Willing to restrict vitamin K intake.
- Stable thyroid dose if appropriate.
- No history of hyperthyroidism, hyperparathyroidism or other metabolic bone diseases.
- Absence of hardware in hip and spine.
- History of malignancy within the last five years.
- Not currently using coumadin or warfarin.
- Vitamin D supplements must be less than 800 IU daily.
- Have not used estrogen or other bone-altering medications (see list in study
description) within the last year.
- No history of liver disease or malabsorption.
- No known allergy to vitamin K.
- Have not participated in an investigational drug trial within the last month.