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.
• Ambulatory.
• 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.