Vitamin K, Bone Density, and Bone Quality
METHODS: Cross-sectional analysis was carried out on 365 elderly subjects, 200 of whom were also included in a 2-year longitudinal follow-up study. Usual dietary intakes were assessed using a semi-quantitative 137-item food frequency questionnaire (FFQ). Vitamin K intake was estimated using the USDA database. Bone biochemical markers were measured in a subset of 125 subjects. Quantitative ultrasound assessment (QUS) was performed at the calcaneus to estimate bone mineral density (BMD), speed of sound (SOS), broadband ultrasound attenuation (BUA) and the quantitative ultrasound index (QUI).
RESULTS: Dietary intake of vitamin K was significantly associated with higher BMD and better QUS. No significant associations were found between vitamin K intake and bone biochemical markers. Those subjects who increased their vitamin K intake showed a lower loss of BMD, a lower decrease in SOS and a nonsignificant increase in BUA.
CONCLUSIONS: High dietary vitamin K intake was associated with superior bone properties. Moreover, an increase in dietary vitamin K was significantly related to lower losses of bone mineral density and smaller increases in the porosity and elasticity attributed to aging, which helps to explain the previously described protective effect of vitamin K intake against osteoporotic fractures
Bulló M, Estruch R, Salas-Salvadó J.
Dietary vitamin K intake is associated with bone quantitative ultrasound measurements but not with bone peripheral biochemical markers in elderly men and women.
Human Nutrition Unit, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain; CIBERobn Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.