Rationale and Design of the Vitamin K2 and Vitamin D3 Intervention Trial in Children and Adolescents With the Low-energy Bone Fractures

At the admission of patients to the orthopedic outpatient clinic, presence of low- energy fractures will be established based on the anamnesis, physical examination and radiological evaluation. Tests to obtain the baseline blood levels of vitamin D3 will be performed, and only children with vitamin D3 levels lower than 30ng/ml in the blood will be included in the study. The selected population will then be randomly assigned by an independent investigator to the three study groups, receiving daily for three months identical- looking soft gel capsules (1 capsule/patient/day) containing supplements of vitamin D3 2,000 IU, 90 mcg of vitamin K2 as menaquinone-7 combined with 2,000 IU D3, and olive oil-containing placebo capsules respectively. During the 3-month follow-up visits to the outpatient orthopedic clinic, the pediatric orthopedist will examine the patient, evaluate the X-ray, and determine the progress in bone union and the range of joint motion. The patients will visit the clinic on weeks 1,2,4,6,8, and 12. The compliance taking the supplements will be assessed by registering a pill count returned by a patient during the scheduled visit. The blood samples will be collected upon admission to the study, day 0, and after the 3-month regimen. The blood samples will be collected for evaluation of bone turnover markers and the status of vitamin K and vitamin D3. The primary evaluation endpoints will include: the dynamics of fracture healing, changes in levels of osteocalcin, and vitamin K and vitamin D3 levels against the placebo group. The bone fracture healing milestones will be based on bone union defined as the absence of pain and the presence of bridging callus in three of the four cortices seen on the front rear projection and lateral radiographic views of the bone. Delayed union is defined as incomplete consolidation at 90 Days