Osteoarthritis is a chronic degenerative disease that causes functional disability with no diseasemodifyingtreatment available. Management of osteoarthritis currently focuses on symptomatic relief or jointreplacement. Recent studies have shown the involvement of vitamin D deficiency affecting the progressionof knee osteoarthritis. However, the clinical use of vitamin D in the management of osteoarthritis remainsunknown. The aim of the study is to investigate the efficacy of vitamin D supplement in management ofknee osteoarthritis. Literature searching on Pubmed and ScienceDirect. The selection was made by title andabstract screening and applying inclusion and exclusion criteria. There were two randomized controlled trialstudies selected for this report. Sanghi et al, reported that vitamin D supplement improves the Western Ontarioand McMaster Universities Osteoarthritis Index (WOMAC) score in patients with osteoarthritis and vitamin Ddeficiency (p<0.02). McAllindon et al, reported there is no improvement of knee pain in the general population(p<0.17). There is no clinical significance of vitamin D supplementation in patients with osteoarthritis withoutproven vitamin D deficiency. However, the use of vitamin D as a therapy for vitamin D deficiency patients hasproven to reduce the pain in osteoarthritis.