In the world of vitamins and supplements, some pairings are just meant to be. The combination of vitamin D3 and K2 is one of those dynamic duos. If you’re already on the vitamin D3 bandwagon, it might be time to invite its sidekick, vitamin K2, to the party. Let's dive into the synergistic relationship of these two essential nutrients.
What Do Vitamin D3 and Vitamin K2 Do?
Vitamin D3: The Sunshine Vitamin
Vitamin D3, also known as cholecalciferol, is essential for our health. It plays a crucial role in:
- Bone health: Vitamin D is an essential nutrient that enhances the absorption of calcium, which is vital for building and maintaining strong bones. Vitamin D creates calcium-binding proteins in the small intestine which transfer calcium from the food we eat into the bloodstream to feed calcium to our cells.1 Without sufficient vitamin D, the body cannot absorb enough calcium, leading to weakened bones and osteoporosis.2 In addition to healthy bones, vitamin D helps to maintain healthy calcium levels in the blood, ensuring proper functioning of the nervous system and muscles as well as immune health.
- Immune system support: Vitamin D supports immune system health by “balancing” different aspects of the immune system. It enhances the germ-fighting effects of antimicrobial peptides as well as white blood cells that are critical to healthy immune defense3—and supports healthy inflammatory responses in the body.4 Adequate levels of vitamin D are associated with a lower risk of infections5 and autoimmune disorders.6,7
- Mood regulation: The role of vitamin D in relation to healthy mood has been studied extensively. Reviews of the data suggest that low levels of vitamin D are associated with an increased risk of low mood and feelings of nervousness.8 Vitamin D supplementation has been shown to be helpful in maintaining a positive mood and emotional balance.9
The Vitamin K Family: Vitamins K1 and K2
The vitamin K family consists of two main groups: vitamin K1 (phylloquinone) and vitamin K2 (menaquinones), which has several further subtypes.
Each vitamin K has distinct roles and sources. Vitamin K1’s primary function is to activate proteins involved in coagulation (the process of blood clotting to prevent excessive bleeding). It is found primarily in green leafy vegetables. Vitamin K2’s primary role is in regulating where calcium is deposited, which is crucial for bone and cardiovascular health.
Vitamin K2: The Unsung Hero
Vitamin K2, also known as menaquinone, is an equally important vitamin for overall wellness. It plays an important role in:
- Calcium metabolism: Vitamin K2 activates important proteins that direct calcium into the bones and teeth, where it’s needed. It, therefore, makes sure that the calcium we absorb from our food gets into our bones and not unintended blood vessels or other organs.
- Heart health: Vitamin K2 deficiency can lead to a phenomenon known as the “calcium paradox,” where calcium is unable to enter the bones and instead accumulates in the blood vessels contributing to a hardening and narrowing of the arteries, AKA atherosclerosis, which can have cardiovascular risks.10
- Bone density: By activating certain proteins, vitamin K2 helps strengthen bones, enhancing their density, which is particularly important for postmenopausal women.11
Vitamin K2, particularly in the form of menaquinone-7 (MK-7), has been highlighted for its role in bone and cardiovascular health due to its greater bioavailability and longer half-life compared to other forms of vitamin K, such as menaquinone-4 (MK-4).12
When combined, vitamin D3 and K2 form a powerhouse team that ensures calcium is absorbed efficiently and directed to the right places, providing comprehensive benefits to your overall health.
Daily Intake of Vitamin D3
The recommended daily intake of vitamin D3 varies depending on age, exposure to sunlight, current vitamin D3 levels and other health conditions.
The Endocrine Society states that the preferred range for optimal vitamin D levels (measured in the blood) are 40-60ng/dl, and its recommendations for daily supplementation are as follows (Note: The lower limit indicates minimum dose for age range and the upper limit indicates possible dose needed to achieve optimal levels):13
- Infants and children ages 0-1: 400-1,000IU
- Children ages 1-18: 600-1,000IU
- Adults 18+: 1,500-2,000IU
- Adults 60+ may require greater than 2,000IU
- Obese children and adults and those on certain medications may require two to three times more vitamin D for their age group
- Pregnant and lactating women require at least 600 but may need up to 2,000IU or greater to reach optimal ranges
Daily Intake of Vitamin K2 (Menaquinone)
Current guidelines for vitamin K2 supplementation are not well-established, and there is no universally accepted Recommended Daily Intake (RDI). However, several studies and reviews provide insights into its potential benefits and suggested dosages:
- Children: unestablished
- Adults: 90 mcg (micrograms), but higher doses may be necessary to achieve optimal bone health
- Menopausal women: 90µg of vitamin K2 has been show to significantly reduce bone loss14
A Note on the Overconsumption of Vitamin D3 & K2
Vitamin D and vitamin K are fat-soluble vitamins and as such can accumulate to toxic levels when too much of either is consumed. It’s important to consult with a healthcare provider about the right dose of vitamin D3 and vitamin K2 for you, to ensure you’re getting the optimal doses for your body.
The Bottom Line
Adding vitamin K2 to your vitamin D3 regimen is a small step that can lead to significant health benefits. Together, they ensure that your body absorbs and utilizes calcium effectively, strengthening your bones, supporting your heart, and boosting your overall health.
If you enjoyed this blog, you may also like these:
Heart Health Heroes: The Vital Roles of Vitamin D3 and Vitamin K2
Nourish Your Body with Vitamin D3 and Vitamin K2
The Power Duo for Strong Bones: Vitamin D3 and Vitamin K2
How Fat-Soluble Vitamins A, E, D, and K Work Together
References:
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3. Bartley J. J Laryngol Otol. 2010;124(5):465-469.
4. Wöbke TK et al. Front Physiol. 2014;5:244.
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6. Athanassiou L et al. Biomolecules. 2023;13(4):709.
7. Cutolo M. Arthritis Res Ther. 2008;10(6):123.
8. Silva MRM et al. Clinics (Sao Paulo). 2021;76:e3155.
9. Cheng YC et al. Depress Anxiety. 2020;37(6):549-564.
10. Merra G et al. Int J Vitam Nutr Res. 2024;94(2):143-152.
11. Huang ZB et al. Osteoporos Int. 2015;26(3):1175-1186.
12. Bus K et al. Foods. 2021;10(12):3136.
13. Holick MF et al. J Clin Endocrinol Metab. 2011;96(7):1911-1930.
14. Zhang Y et al. Calcif Tissue Int. 2020;106(5):476-485.
