• People already taking higher doses of D3— from about 1000 IU per day, K2 becomes increasingly beneficial.
• 40+ target group— from the age of 40, the risk of bone loss increases, and calcium distribution to the bones becomes more critical.
• Women during and after menopause — declining estrogen levels accelerate bone loss; K2 + D3 + sufficient calcium is then a commonly used combination.
• People actively concerned with their vascular health:K2 helps keep calcium in the right place.
• Vegans and vegetarians— who get almost no K2 through their diet.

For those who only use a low maintenance dose of D3 (e.g., 400-800 IU) and have no specific risk factors, K2 as a separate supplement is less critical. But as soon as the D3 dosage becomes higher, or with an increased risk of bone loss, the interaction between K2 and D3 becomes increasingly important.

There are three main routes to combine K2 and D3 — as a ready-made combination product, as a separate supplement to an existing D3 intake, or as part of a broader bone formula. Which route is best depends on your current supplement use and preference.

Capsules (combination product) 

A combination capsule with both K2 and D3 is the most practical route: one capsule per day, a fixed ratio between the two vitamins, taken with a fat-containing meal for optimal absorption. Pay attention to the K2 form (preferably choose MK-7) and the dosage — for maintenance, 75-100 micrograms of K2 per day is a common choice.

Liquid (drops) 

For those who do not want to swallow capsules, or for those who want to be able to vary the dosage, a liquid combination offers flexibility. Drops are also useful for the elderly or people with swallowing difficulties.

Bone formula (all-in-one) 

For those who want more than just K2 + D3, there are bone formulas that contain calcium, magnesium, and silicon in addition to K2 and D3. These are particularly suitable for the 40+ age group or during peri-menopause.

In the Plenthera range 

Arthur Andrew KD Ultracombines full-spectrum vitamin K2 (MK-4 + MK-7) with vegan vitamin D3 (4000 IU) in one capsule — suitable for those who combine a high D3 dosage with effective K2 supplementation. Vegan and hypoallergenic. Plenthera is the exclusive supplier of Arthur Andrew Medicalin the Netherlands and Belgium. For those who prefer a ready-made capsule with a classic ratio: Vitals Vitamin K2+D3 (60 caps, vegan). For drops fans: Trace Liquid D3+K2 (59 ml).

Disclaimer: This article is for informational purposes only and does not replace medical advice. A dietary supplement is not a substitute for a varied and balanced diet and a healthy lifestyle. If in doubt or taking medication: consult a doctor or pharmacist. Do not exceed the recommended daily dose. Keep out of reach of young children.