Sodium dehydroacetate (DHA-Na) is a fungicidal preservative widely used in food and animal feed. DHA-Na can induce coagulation disorders in rats and poultry by inhibiting carboxylation of vitamin K-dependent proteins; it can also impair bone development in zebrafish. However, the effects of DHA-Na on broiler chicken bones remain unknown. Here, we assessed whether DHA-Na impairs bone development in broiler chickens. We administered Suji yellow chickens with 200 to 800 mg/kg DHA-Na, 2 mg/kg vitamin K, or both for 2 mo. Bone metabolite–related serum indicators, tissue micromorphology, and relevant protein expression were monitored during the treatment period. We also assessed primary chicken osteoblast activity, differentiation, and bone metabolite–related proteins after treatment with DHA-Na, vitamin K, or both. The results demonstrated that DHA-Na reduced bone index values and serum and bone osteoblast differentiation marker levels but blocked bone vitamin K cycle. DHA-Na also increased serum osteoclast differentiation marker levels, as well as the bone ratio of receptor activator of nuclear factor kappa-Β ligand to osteoprotegerin ratio. Moreover, DHA-Na reduced bone trabecular number, thickness, and area and increased trabecular separation considerably. In general, compared with the control group, the DHA-Na group demonstrated impairments in osteoblast activity and differentiation, as well as in the vitamin K cycle. By contrast, vitamin K supplementation led to considerable attenuation of the DHA-Na-induced decrease in osteogenic marker levels, along with a considerable increase in serum bone absorption marker levels and restoration of DHA-Na-induced bone microstructure damage. Vitamin K also attenuated DHA-Na-induced impairment in osteoclasts. In conclusion, the results indicated that in broiler chickens, DHA-Na supplementation can damage bones by inhibiting osteoblast function and increasing osteoclast activity; this damage can be prevented through vitamin K supplementation.