From the Guidelines
Vitamin K2 supplementation is not necessary when taking Vitamin D3, but it may be beneficial for directing calcium to bones and reducing arterial calcification risk. When considering the administration of Vitamin K2 with Vitamin D3, it's essential to understand the role of each vitamin. Vitamin D3, or cholecalciferol, is crucial for calcium absorption, and its supplementation is recommended to maintain serum 25(OH) D levels at 30 ng/ml or higher for bone health 1. The study by the NCCN task force report on bone health in cancer care suggests that vitamin D3 could be more effective in raising 25(OH) D concentrations and maintaining those levels for a longer time when longer dosing intervals are employed 1. However, the same study does not mention the necessity of administering Vitamin K2 with Vitamin D3. Some key points to consider when supplementing with Vitamin D3 include:
- The typical recommended dosage of vitamin D3 is 800 to 1000 IU daily, with a caveat that many patients may need more than the recommended amount and should be repleted based on serum 25(OH) D level 1.
- Vitamin D toxicity is uncommon but may occur with daily doses of more than 50,000 IU per day that produce 25(OH) D levels larger than 150 ng/mL 1. While the evidence does not necessitate the administration of Vitamin K2 with Vitamin D3, taking them together may have synergistic effects on bone health and potentially reduce the risk of arterial calcification. It is crucial to consult a healthcare provider before taking any supplements, especially for individuals on blood-thinning medications like warfarin, as vitamin K2 may interfere with these medications. In terms of dosage, a typical range for vitamin K2 is 100-200 mcg (preferably as MK-7 form) with 1000-5000 IU of vitamin D3 daily, though individual needs may vary.
From the Research
Vitamin K2 and Vitamin D3 Administration
- The administration of Vitamin K2 with Vitamin D3 (Cholecalciferol) has been studied in various research papers 2, 3, 4.
- A study published in 2000 found that the combined administration of vitamin D3 and vitamin K2 increased bone mineral density (BMD) of the lumbar spine in postmenopausal women with osteoporosis compared to calcium administration alone 2.
- However, a 2021 study found that vitamin K2 supplementation as an add-on to calcium and vitamin D supplementation did not affect biochemical markers of bone turnover, bone mineral density, or bone microarchitecture in postmenopausal women with osteopenia 3.
- Another study published in 2024 highlighted the importance of vitamin K and the combination of vitamins K and D for calcium metabolism and bone health, suggesting that an adequate supply of vitamin K, on top of an optimal vitamin D status, seems to add to the benefit of maintaining bone health 4.
Vitamin D3 Supplementation
- Research has also focused on vitamin D3 supplementation, with a 2014 study recommending that vitamin D3 be used for supplementation over vitamin D2, and concluding that single vitamin D3 doses ≥300,000 IU are most effective at improving vitamin D status and suppressing parathyroid hormone (PTH) concentrations for up to 3 months 5.
- A 2024 review argued for a daily dose of 2000 international units (50 µg) of vitamin D for adults in the general population, citing evidence that such a dose may improve some health outcomes and is sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) and above 75 nmol/L (30 ng/mL) in >99% and >90% of the general adult population, respectively 6.
Interaction between Vitamins K and D
- The interaction between vitamins K and D has been explored, with evidence suggesting that vitamin K-dependent proteins, such as osteocalcin and matrix Gla-protein (MGP), play a crucial role in bone health 4.
- The combined action of vitamins K and D may contribute to the maintenance of bone health by promoting bone mineralization and reducing the risk of osteoporosis 4.