Why Vitamin D3 Works Best with Vitamin K2
Vitamin D3 and vitamin K2 are often combined because they play complementary roles in calcium metabolism and bone health. Vitamin D3 helps the body absorb calcium, while vitamin K contributes to the maintenance of normal bones.
Together, they provide nutritional support for healthy bones and teeth, normal immune function and psychological function.
Key takeaway
Vitamin D3 helps the body absorb calcium from food. Vitamin K2, a form of vitamin K, supports the activation of proteins involved in normal bone maintenance. This is why D3 and K2 are commonly used together in daily supplements.
However, vitamin D3 does not stop working without K2. The combination is best understood as complementary, rather than essential for everyone.
What does vitamin D3 do?
Vitamin D3, also known as cholecalciferol, is a form of vitamin D produced by the skin in response to sunlight. It is also found in some foods and supplements.
Vitamin D helps regulate calcium and phosphate in the body. These minerals are important for maintaining healthy bones, teeth and muscles. Vitamin D also contributes to the normal function of the immune system and normal psychological function.
In the UK, sunlight is not strong enough for the body to make sufficient vitamin D between October and early March. This is why government guidance advises most people to consider taking a daily supplement containing 10 micrograms of vitamin D during the autumn and winter months. NHS vitamin D guidance
Vitamin D3 may be particularly important for people who:
- Spend little time outdoors
- Have limited exposure to sunlight
- Cover most of their skin when outside
- Have darker skin
- Are unable to obtain enough vitamin D through diet and sunlight
What does vitamin K2 do?
Vitamin K2 is one of the forms of vitamin K. Proto-col Vitamin D3 & K2 contains menaquinone-7, also known as MK-7.
Vitamin K contributes to the maintenance of normal bones. It is also involved in the activation of vitamin K-dependent proteins, including osteocalcin, which is found in bone tissue.
Vitamin K2 is found in some fermented foods and animal-based foods. However, the amount people obtain through their diet can vary depending on their eating habits.
The body needs vitamin K for several functions, including normal blood clotting and bone health. The evidence surrounding vitamin K supplementation and bone density is still developing, so it should not be presented as a treatment for osteoporosis. NIH vitamin K fact sheet
Why are vitamin D3 and K2 taken together?
Vitamin D3 and K2 have different but related functions:
- Vitamin D3 helps the body absorb calcium.
- Vitamin K contributes to the maintenance of normal bones.
- Vitamin D contributes to the maintenance of normal bones and teeth.
- Both nutrients support processes involved in healthy bone metabolism.
A simple way to understand the relationship is that vitamin D3 helps make calcium available to the body, while vitamin K helps activate proteins involved in the way calcium is used in bone tissue.
Research reviews suggest that having an adequate supply of both vitamin D and vitamin K may support bone health. However, more research is needed to establish exactly how much additional benefit comes from taking the two nutrients together. 2024 review of vitamins D and K
Can vitamin D3 and K2 support bone and teeth health?
Yes. Vitamin D contributes to the maintenance of normal bones and teeth, while vitamin K contributes to the maintenance of normal bones.
Calcium is also important for bone health. Vitamin D helps regulate calcium absorption, but a supplement should not be seen as a replacement for a balanced diet containing calcium-rich foods.
Good sources of calcium include:
- Milk, yoghurt and cheese
- Calcium-fortified plant drinks
- Tinned fish with edible bones
- Tofu made with calcium
- Green leafy vegetables
Healthy bones also depend on regular weight-bearing exercise, resistance training, adequate protein, a balanced diet and avoiding smoking.
Can vitamin D3 help your mood?
Vitamin D contributes to normal psychological function. This means it plays a role in the normal functioning of the mind and nervous system.
Some people associate vitamin D with mood because vitamin D levels can be lower during the winter, when there is less sunlight. However, vitamin D supplements should not be described as a treatment for depression or other mental health conditions.
If you are experiencing persistent low mood, speak to your GP or another qualified healthcare professional.
Can vitamin D3 and K2 support the immune system?
Vitamin D contributes to the normal function of the immune system. This means it helps support normal immune function, but it does not prevent every illness or replace a healthy lifestyle.
A resilient immune system is also supported by:
- Regular sleep
- A varied and balanced diet
- Regular movement
- Good stress management
- Adequate hydration
How should you take vitamin D3 and K2?
Proto-col Vitamin D3 & K2 provides a one-year supply of 365 tablets in one pouch. It contains vitamin D3 as cholecalciferol and vitamin K2 as menaquinone-7, or MK-7. It is suitable for vegetarians but not vegans. View Proto-col Vitamin D3 & K2
Who should speak to a healthcare professional first?
Speak to your GP, pharmacist or another qualified healthcare professional before taking vitamin D3 and K2 if you:
- Take warfarin or another anticoagulant medication
- Have kidney disease or a condition affecting calcium levels
- Have a condition that affects the absorption of nutrients
- Are taking other vitamin D or calcium supplements
- Are pregnant or breastfeeding
- Have been diagnosed with vitamin D deficiency or osteoporosis
Vitamin K can interact with warfarin and similar anticoagulant medicines. People taking these medicines should keep their vitamin K intake consistent and seek medical advice before starting a new supplement. NIH guidance on vitamin K and anticoagulants
Frequently asked questions
Is vitamin D3 better with K2?
Vitamin D3 can work on its own, but it is often combined with K2 because the two nutrients have complementary roles in calcium metabolism and bone health. Vitamin D3 helps with calcium absorption, while vitamin K contributes to the maintenance of normal bones.
Does vitamin D3 without K2 work?
Yes. Vitamin D3 still supports calcium absorption, normal bones, normal teeth, normal muscle function and normal immune function without added K2. K2 is included to provide additional nutritional support for normal bone maintenance.
What is the difference between vitamin D3 and K2?
Vitamin D3 is a form of vitamin D that helps regulate calcium and phosphate. Vitamin K2 is a form of vitamin K involved in the activation of vitamin K-dependent proteins and the maintenance of normal bones.
Can you take vitamin D3 and K2 every day?
Many people take vitamin D3 and K2 as part of a daily routine. Always follow the product instructions and avoid taking more vitamin D than recommended. If you take medication or have an underlying health condition, speak to a healthcare professional first.
Is Proto-col Vitamin D3 & K2 suitable for vegetarians?
Yes. Proto-col Vitamin D3 & K2 is suitable for vegetarians but is not suitable for vegans.
A simple daily routine for bones, teeth and immunity
Vitamin D3 and K2 offer complementary nutritional support. Vitamin D3 helps the body absorb calcium, while vitamin K contributes to the maintenance of normal bones.
Proto-col Vitamin D3 & K2 combines vitamin D3 with MK-7 in a convenient daily tablet. It is a simple way to support your everyday nutrition, particularly during the darker months of the year.