Vitamin K has some scientific basis for its use in supporting bone health and potentially treating osteoporosis, though the evidence is considered limited and of moderate quality. Vitamin K is essential for the γ-carboxylation of osteocalcin, a protein involved in bone mineralization. Epidemiological studies have shown an association between low dietary intake of vitamin K and increased risk of fractures and lower bone mineral density (BMD), especially in older adults. Randomized controlled trials (RCTs) have evaluated the effect of vitamin K supplementation (both K1 and K2 forms) on bone health. Some studies, particularly from Japan using high-dose vitamin K2 (menaquinone-4), have shown a reduction in fracture risk and maintenance of BMD, mainly in postmenopausal women. However, results from western populations and studies using lower doses or vitamin K1 are less consistent, and meta-analyses often conclude that while there is a biological plausibility and some supportive data, the overall quality of evidence is low to moderate and not sufficient to recommend vitamin K as a primary therapy for osteoporosis. Clinical guidelines do not routinely recommend vitamin K supplementation for osteoporosis treatment due to insufficient conclusive evidence. In summary, vitamin K has some scientific support for a role in bone health, but the evidence for its use in treating osteoporosis specifically is limited and not definitive.