Vitamin K2

Yes. Vitamin K can have a serious interaction with anticoagulants like warfarin (Coumadin), so consistent intake is needed. Antibiotics, especially cephalosporins, may lower vitamin K status. Bile acid sequestrants (cholestyramine, colestipol) and the weight-loss drug orlistat can reduce its absorption. Discuss your vitamin K status with your health care provider. — per the NIH Office of Dietary Supplements; general information, not medical advice.

The cheapest vitamin k2 we track works out to $0.02 , against a typical $0.12 across the 42 we can price per dose — about $0.46 a month at the cheapest. That is real from live Amazon US prices, not the sticker price. The full ranking is on the Best Vitamin K2 page.

BulkSupplements.com Vitamin K2 Powder - Vitamin K2 , as Menaquinone Powder… at $0.02 — the lowest cost-per-dose vitamin k2 in our catalog. See the full ranking on the Best Vitamin K2 page.

We're tracking 90 active Vitamin K2 deals across Amazon US and partner retailers, ranked by community votes and cost-per-dose — not paid placement.

Across the 42 Vitamin K2 deals we can price per dose (combination products are left out — their single label dose belongs to whichever ingredient the product is built around) the median cost-per-dose is $0.121; the cheapest quartile comes in under $0.075 . Anything below the median is a solid deal for the same molecule.

Deals are submitted by the community and ranked by net votes (hot minus cold) plus cost-per-dose normalised across container sizes. We take no affiliate kickbacks for ordering; sponsored slots, when present, are clearly badged.

Most K2 supplements provide 90–120 mcg/day, usually as the well-absorbed form. It's fat-soluble, so take it with a meal — and it's commonly paired with vitamin D3. If you take a blood thinner like warfarin, talk to your doctor first, because vitamin K affects how it works. General reference, not medical advice.

The Food and Nutrition Board did not establish a (UL) for vitamin K because of its low potential for toxicity, stating that "no adverse effects associated with vitamin K consumption from food or supplements have been reported in humans or animals" — per the NIH Office of Dietary Supplements.

Clinically significant vitamin K deficiency in adults is very rare and is usually limited to people with malabsorption disorders (such as cystic fibrosis, celiac disease, ulcerative colitis, or short bowel syndrome) or those taking drugs that interfere with vitamin K metabolism; newborns not treated with vitamin K at birth are also at risk because placental transfer is poor. Bleeding and hemorrhage are the classic signs of deficiency, occurring only in severe cases, and in infants it can cause vitamin K deficiency bleeding (VKDB) — per the NIH Office of Dietary Supplements.

Food sources of phylloquinone (vitamin K1) include vegetables — especially green leafy vegetables — vegetable oils, and some fruits, while meat, dairy foods, and eggs contain low levels of phylloquinone but modest amounts of menaquinones, and natto (fermented soybeans) has high amounts of menaquinones. The most common sources in the U.S. diet are spinach, broccoli, iceberg lettuce, and fats and oils, particularly soybean and canola oil; among the richest are natto, collards, turnip greens, spinach, kale, and broccoli — per the NIH Office of Dietary Supplements.