Does the vitamin K in veggies lettuce build stronger bones? Original paper

From childhood to old age, broken bones are painful and greatly interrupt daily life. Higher intakes of green, leafy vegetables are associated with lower risks of fractures. This may be due to those vegetables being rich in vitamin K.

All 30 participants of this crossover trial went through three 4-week experiments (with a 4-week washout in between): vegetable drinks high in K₁ (162.3 μg/day), vegetable drinks low in K₁ (9.4 μg/day), and placebo drinks with nearly no K₁ (1.3 μg/day). The drinks were calorie matched. Blood markers for bone metabolism were measured before and after each experiment.

Blood markers indicative of improved bone metabolism (including reduced blood levels of osteocalcin) were highest after the “high K₁” experiment. That some other compound in the drink was responsible cannot be ruled out, however. Further research is also required to determine if this dietary intervention translates to a reduction in the risk of fractures.