Vitamin D3 1000IU + K2

What Is Vitamin D3 With MK-4?

Menaquinone-4 is the vitamin K2 form found in animal tissue and the one human cells build for themselves out of other vitamin K forms. It is paired here with cholecalciferol at 25 mcg per serving, alongside 45 mcg of MK-4 per serving, in a dry cellulose capsule with a rice flour base.

How It Works in the Body

Vitamin D3 is converted twice, first in the liver and then in the kidney, before the finished form tells the intestine to make calcium transporters. MK-4 takes another route. Tissues convert other vitamin K forms into it locally, and it turns up in brain, pancreas and salivary gland. Its job there is carboxylation, the chemical step that gives certain proteins their calcium-binding grip.

What It Supports

• The carboxylation step: Vitamin K is the cofactor for carboxylating Gla proteins, including the osteocalcin in bone, which supports bone health.
• A tissue-made vitamer: MK-4 is the menaquinone human tissues make for themselves, with a four-unit side chain.
• Calcium absorption: The active form of vitamin D switches on the intestinal transporters that move calcium into the blood.
• Normal immune function: Immune cells carry vitamin D receptors and make the active form locally, so vitamin D plays a role in normal immune function.

Who It May Suit

People who want a smaller daily amount of D3 with K2 alongside, often because food or a multivitamin already supplies some. Vegetarians can take it, since the capsule is plant cellulose with rice flour and no gelatin. It also suits people who prefer a dry capsule to an oil softgel.

Good To Know

Fat-soluble vitamins are absorbed along with dietary fat, and this is a dry capsule rather than an oil softgel. Talk with your provider before use if you take warfarin or a similar anticoagulant, since those medicines act against vitamin K. Ask as well if you are pregnant or take digoxin.