Technical Abstract: Poor diet may affect bone status by displacement of nutrients involved in bone health. Dihydrophylloquinone, a form of vitamin K present in foods made with partially-hydrogenated fat, is a potential marker of a low quality dietary pattern. We examined cross-sectional associations between dihydrophylloquinone intake and bone mineral density (BMD) of the hip and spine in men and women. Dihydrophylloquinone intake was estimated by food frequency questionnaire, and BMD (g/cm2) was measured by DXA, in 2544 men and women (mean age 59 years) participating in the Framingham Offspring Study. General linear models were used to examine associations between dihydrophylloquinone intake in tertiles (less than 15.5, 15.5-29.5, greater than 29.5 'g/day) and BMD at the hip and spine after adjustment for age, body mass index, energy, calcium, and vitamin D intakes, smoking, physical activity, and for women, menopausal status and current estrogen use. Higher dihydrophylloquinone intakes were associated with lower mean BMD at the femoral neck (lowest to highest tertile, 0.934, 0.927, 0.917, p-trend=0.02), trochanter (0.811, 0.805, 0.795, p-trend=0.02), and spine (1.250, 1.243 1.227, p-trend=0.03) in men and women, after adjustment for covariates. Further adjustment for markers of healthy and low quality dietary patterns did not affect the observed associations. In conclusions, higher dihydrophylloquinone intake was associated with lower BMD in men and women. This association remained significant after adjustment for other markers of diet quality, suggesting that dihydrophylloquinone may have a direct biological effect on bone.