Can Vitamin K Help Prevent and Treat Osteoporosis?

Vitamin K and vitamin K2 may help strengthen bones in some people at risk of osteoporosis, especially if combined with vitamin D and calcium.

Osteoporosis is a condition where bone tissue becomes less dense over time. Loss of bone density significantly increases the risk of bone fractures. Some studies suggest that vitamin K may help treat or prevent osteoporosis, but results are controversial.(53)

Who Is at Risk of Osteoporosis?

Although it can affect both older men and women, it is recognized as a major health issue for postmenopausal women since decreases in the hormone estrogen can result in increases in demineralization of bone.(53)

How Can Vitamin K Help?

Vitamin K is important for healthy bones because of its interactions with bone proteins. Through a process called carboxylation, vitamin K changes these proteins so they can bind to calcium, an important mineral for bones:(142253)

Table 5: Proteins in Bone Vitamin K Carboxylates
Protein Importance in Bone Health

Plays a role in:

  • Bone mineralization.
  • Bone density.
  • Facilitates normal bone growth.
  • Prevents calcification of soft tissues.
Protein S The role of protein S in bone density is unclear, except that children born with a deficiency in this protein have reduced bone density.

Vitamin K deficiency can result in non-carboxylated proteins. Higher blood serum levels of non-carboxylated bone proteins are linked to reduced bone density and greater risk of bone fracture in elderly women. Additionally, research indicates that drugs that block vitamin K activity (e.g., anticoagulant drugs) may reduce bone density in the arm.(142253)

Preclinical and Clinical Evidence

Studies have shown that postmenopausal women and elderly men who take vitamin K1 supplements have increased levels of carboxylated bone proteins. Whether or not use of vitamin K supplements improves bone density and decreases risk of fractures is still unclear, however, because of conflicting study results.(1)

Vitamin K Supports Bone Health if There's Vitamin K Deficiency

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Research shows a link between vitamin K levels and bone health in older populations or in patients with diseases that cause vitamin K deficiency and increased risk for osteoporosis. Animal and clinical studies suggest vitamin K2 or vitamin K1 in combination with other supplements may help:

Vitamin K2 and Reduced Bone Fractures

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Clinical studies suggest vitamin K2 may also prevent new fractures in patients with osteoporosis.(54)

Reports of No Benefit on Bone Density from Vitamin K in Some Populations

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Conversely, some research showed that increased vitamin K intake, by itself, showed no benefit for bone density in some groups:

Bottom Line

It is difficult to figure out if assess the benefit of vitamin K on osteoporosis based on bone density alone. This is due to the wide array of study types involving disparate populations and different forms of vitamin K.(3)

However, a 2006 meta-analysis was conducted on similar type studies measuring bone density and fracture risk. The researchers concluded that vitamin K supplementation (primarily vitamin K2) does offer bone-strengthening benefits - particularly for Asian people. Vitamin K may also be helpful in some people at risk for vitamin K deficiency, particularly when combined with other supplements or healthy diets.(353-57)

However, these same vitamin K antagonists apparently have no effect on the hip and back bones.(1)