Why take vitamin D3 with K2?

Vitamin D3 helps your body absorb calcium from food ^[1]. Vitamin K2 switches on proteins that matter for bone and that help keep calcium out of artery walls ^[2]. This is why the two are often taken together, and some studies in people show that K2 can slow calcium build-up in the arteries ^[3][4].

Why take vitamin D at all?

We at Nutrizy, consider vitamin D an essential supplement for anyone who needs to correct low vitamin D or cover their daily needs. One of vitamin D3's main jobs is to increase how much calcium your intestines absorb from food ^[1].

Can vitamin D cause calcium build-up in your arteries?

The real risk is too much vitamin D. Taking very high doses for a long time can push the calcium in your blood too high, a condition called hypercalcemia ^[5]. In animal studies, toxic doses of vitamin D caused calcium deposits in the arteries ^[6].

How does vitamin K2 help?

This is where K2 comes into the game. Vitamin K2 activates proteins that only work once vitamin K has switched them on ^[2]. One is called osteocalcin, the most common protein in bone after collagen ^[8]. Another is called matrix Gla protein, and it helps stop calcium from settling in artery walls ^[9].

Vitamin D makes the body produce more of these proteins, and they need vitamin K to work ^[2]. Researchers think this is why the two vitamins may work better together than either one alone ^[2].

What do studies in people show for the arteries?

A 2019 review of 13 trials found that vitamin K supplements reduced calcium build-up in blood vessels ^[3].

A 2026 Danish trial gave 398 people with severe calcium in their heart arteries vitamin K2 (720 mcg) with vitamin D3 (25 mcg, or 1,000 IU) every day for 2 years. On heart scans, their calcium score rose by 196 points, compared with 248 in the group on placebo ^[4].

Which products combine D3 and K2?

Nutrizy stocks the products below.

Vitamin D3 + K245,000 IQDView

Vitamin D3K235,000 IQDView