Study design
This randomized, double-blind, four-arm, pilot study evaluated the effects of EC-HC-II on joint, bone, and muscle functions in patients with knee OA (NCT04483024). After enrollment, participants were randomly allocated in equal proportions to four supplement groups: EC-HC-II, HC-II, glucosamine HCl, and placebo. Eligible participants were randomly assigned to groups at a 1:1:1:1 ratio. A block randomization list with a block size of eight was generated using Statistical Analysis Software (SAS). Participants were instructed to consume one bottle (68 mL) of the experimental product daily in the morning (after breakfast) for 24 weeks and perform resistance exercises for 30 min twice per week according to training manual. Product consumption and resistance training were recorded on participant diary cards. Each participant undertook follow-up assessments at 8, 16, and 24 weeks. This study designed and administered a food questionnaire on the participant’s calcium, vitamin D, and protein intake every week before assessments. Throughout the study, the use of analgesics as rescue medication was permitted.The study was approved by the Institutional Review Board of blinded information and conducted in accordance with the Declaration of Helsinki and local regulations. Written informed consent was obtained from participants before beginning the study.