Table 2.
Summary of the effects of vitamin K (VK) on bone health in humans over the past decade. (vitamin K has a beneficial effect on bone).
| Study Population | Interventions | Results | Reference |
|---|---|---|---|
| Healthy men (≥65 years, n = 1662) | Natto, <1 pack/week vs. 1 pack/week vs. several packs/week vs. 1 pack/day and more; 4–5 years | High natto intake was associated with lower ucOC and higher BMD | Fujita et al. (2012) [74] |
| Women with multiple vertebral fractures related to their normal pregnancies (31.5 years, n = 4) | VK2 (45 mg/d); 5 months to 1 year | Their back pain had completely disappeared | Tsuchie et al. (2012) [75] |
| Postmenopausal rheumatoid arthritis patients with untreated osteoporosis or osteopenia (young adults, n = 62) | VK2 (45 mg/d) plus alendronate (35 mg/week) vs. alendronate (35 mg/week); 1 year | Combined therapy increases lumbar spine and femoral neck bone density | Suzuki et al. (2013) [76] |
| Healthy postmenopausal women (55 to 65 years, n = 244) | MK-7 (180 μg/d) vs. placebo; 3 years | Prevention of bone loss | Knapen et al. (2013) [77] |
| Adults (>19 years, n = 7092) | Total VK, men: ≤58.07 (μg/d) vs. 58.09–121.91 (μg/d) vs. ≥121.93 (μg/d); women: ≤58.23 (μg/d) vs. 58.32–129.42 (μg/d) vs. ≥129.45 (μg/d) | Low dietary VK intake was associated with low bone mineral density | Kim, Kim, and Sohn (2015) [78] |
| Men and women (65 to 75 years, n = 21,774) | Serum VK and VK concentrations, high VK and high VD vs. high VK and low VD vs. low VK and high VD vs. low VK and low VD | An increased risk of hip fractures in elderly men and women with low concentrations of both VD and VK1 | Finnes et al. (2016) [79] |
| Postmenopausal women (60 to 80 years, n = 148) | MK-7 (375 μg/d) vs. placebo; 1 year | Protection of trabeculae | Rønn et al. (2016) [80] |
| Adults with cerebral palsy and osteoporosis (n = 16) | VK2 (45 mg/d); 1 year | A positive effect on bone mineral density | Kodama et al. (2017) [81] |
| Patients with end-stage renal disease (54.7 ± 12.7 years, n = 468) | Serum dp-ucMGP, 300–862 nmol/L vs. 864–1447 nmol/L vs. 1465–10717 nmol/L | Poor VK status is associated with low bone mineral density | Evenepoel et al. (2019) [70] |
| Men and women (40 to 74 years, n = 30) | Phase 1 VK1 (164.3 μg/d) vs. phase 2 VK1 (9.4 μg/d) vs. none; three 4-week experimental phases | Reduce serum total OC and ucOC | Sim et al. (2020) [82] |
| Women with postmenopausal osteoporosis (68.7 years, n = 374) | Prevalent fractures vs. no fractures | VK status is associated with bone health including fracture risk and bone strength | Moore et al. (2020) [83] |
ucOC, uncarboxylated osteocalcin; BMD, bone mineral density; VD, vitamin D; dp-ucMGP, dephosphorylated uncarboxylated matrix Gla-protein.