Why D3 and K2 belong together

The NHS recommends all UK adults supplement with vitamin D from October to March. But vitamin D3 on its own only gets calcium into your bloodstream. It doesn’t control where that calcium ends up.

That’s where K2 comes in. Vitamin K2 activates osteocalcin, the protein that directs calcium into bones and teeth rather than soft tissue and arteries. Without adequate K2, the calcium that D3 helps you absorb may not reach where it’s most useful.

This formula uses K2 as MK-7, the longer-acting form that stays active in the body for up to 72 hours, compared with just a few hours for MK-4. It also includes MCT oil because both D3 and K2 are fat-soluble vitamins. Taking them alongside a fat source improves absorption, so you don’t need to worry about timing your capsule with a meal.

Research into the D3-K2 synergy has been published in journals including the European Journal of Clinical Nutrition and the Journal of Bone and Mineral Research, with findings suggesting the combination may support calcium metabolism more effectively than either vitamin taken alone.

What's in each capsule (and why)

Every ingredient in this vitamin D3 K2 supplement is here for a specific reason:

• 4000IU Vitamin D3 (cholecalciferol, from lanolin) — the dose most commonly recommended by UK practitioners for adults with low or insufficient levels. Supports calcium absorption, immune function, and muscle health.
• 90mcg Vitamin K2 (as MK-7) — directs calcium to bones and teeth. The MK-7 form has a longer half-life than MK-4, meaning one daily dose maintains consistent blood levels.
• 5mg Zinc (as zinc citrate) — a highly bioavailable form. Zinc supports immune function and is involved in over 300 enzymatic processes in the body, including those related to bone metabolism.
• 3mg Boron — a trace mineral that supports the metabolism of calcium, magnesium, and vitamin D. Often missing from standard D3 K2 supplements, yet research suggests it plays a role in how your body uses these nutrients.
• MCT Oil — included as a fat source to improve absorption of the fat-soluble vitamins (D3 and K2) in the formula.

No magnesium stearate. No titanium dioxide. No synthetic fillers or artificial colours. HPMC capsule shell. Manufactured in the UK to GMP and BRCGS standards.