The Power Duo: Vitamin D3 & K2 - Why They Work Better Together
Sunshine, Strong Bones & a Smarter Supplement
You’ve probably heard about vitamin D being the “sunshine vitamin” — helping with bone health, mood, and immunity. But did you know that vitamin K2 plays a key supporting role in making sure all that extra calcium gets to the right places in your body?
Together, vitamins D3 and K2 act like a well-coordinated team. D3 helps your body absorb calcium, while K2 tells that calcium where to go — into your bones and teeth instead of soft tissues like your arteries.
How D3 and K2 Work in Sync
Think of vitamin D3 as the “delivery manager” and vitamin K2 as the “traffic controller.”
Vitamin D3 increases calcium absorption from the gut and helps your body make proteins that use calcium for bone strength.
Vitamin K2 activates those proteins (like osteocalcin and matrix Gla protein) so they can actually bind calcium into bone and keep it out of blood vessels.
When D3 and K2 are taken together, you’re not just improving calcium absorption — you’re also improving calcium placement.
More Than Just Bones — It Supports Heart Health Too
Research shows that having both vitamins at good levels may support cardiovascular health by reducing calcium buildup in arteries. Without enough K2, the proteins that protect your arteries stay “switched off,” allowing calcium to harden vessel walls over time.
This balance helps your heart stay healthy and your bones stay strong - a win-win combination supported by multiple studies.
Where to Find Them Naturally
Vitamin D3: Sun exposure is the best source, but it’s also found in fatty fish (salmon, sardines, tuna), eggs, and fortified dairy or plant milks.
Vitamin K2: Found in fermented foods like natto (fermented soybeans), some cheeses, and yoghurt, as well as in small amounts in meat and eggs.
If your diet or lifestyle means you don’t get enough of these, a combined supplement may help fill the gap - especially during winter or if you spend most of your time indoors.
What to Keep in Mind
Always check with your GP or dietitian before starting a new supplement.
Consistency is key - fat-soluble vitamins like D and K are best absorbed with meals that contain healthy fats.
Balance matters: taking large doses of D3 without enough K2 might increase calcium in the blood rather than bones.
Easy Recipe Idea: “Sunny Salmon Bowl”
A meal rich in D3, K2, calcium, and heart-healthy fats.
Ingredients:
1 salmon fillet (pan-seared or baked)
1 cup brown rice or quinoa
½ avocado
½ cup steamed edamame or peas
1 tbsp sauerkraut or kimchi (for a K2 boost!)
Lemon juice, olive oil, and sesame seeds to serve
Method:
Cook the base: Prepare brown rice or quinoa according to packet instructions and set aside.
Cook the salmon: Season the fillet with a little olive oil, salt, and pepper. Pan-sear for 3–4 minutes per side (or bake at 180 °C for 12–15 minutes) until cooked through.
Prepare toppings: Slice avocado and lightly steam edamame or peas.
Assemble the bowl: Add rice or quinoa to a bowl, top with salmon, avocado, edamame, and a spoonful of sauerkraut or kimchi.
Finish and serve: Drizzle with lemon juice and olive oil, sprinkle with sesame seeds, and enjoy warm or chilled.
Why it works:
Salmon gives you D3 and omega-3s, while fermented foods like sauerkraut add K2, a delicious way to nourish both bones and heart.
The Takeaway
D3 and K2 are like the dynamic duo for bone and cardiovascular health, working better together than alone. They’re safe, effective, and a smart way to get the most from your nutrition.
If you’re unsure which supplement is right for you or want to optimise your intake through food, our team can help.
Book an appointment with one of our dietitians for tailored guidance and supplement advice.