uses JavaScript to provide the best possible experience for our content, but your browser has it disabled. Learn how to enable it here.


White Plains, New York, June 1, 2017 — Vitamin K plays an important role in proper blood clotting as well as with calcium utilization in bones and the cardiovascular system, but do most people need a vitamin K supplement? And do products on the market contain what's claimed on their labels? To find out, reviewed the clinical evidence, and purchased and rigorously tested popular vitamin K supplements sold in the U.S.'s tests revealed that three products contained less vitamin K or other key ingredients than claimed, took longer than normally expected to break apart in disintegration testing, and/or were contaminated with lead. Among products which were Approved, identified its Top Picks. Its selections include vitamin K-only supplements as well as combination products containing vitamin D, calcium and/or magnesium. The results are now available in's new Vitamin K Supplements Review.

As explained in the Review, supplements containing vitamin K can be helpful in treating poor blood clotting caused by deficiency. Although deficiency is also associated with atherosclerosis, lower bone mass and, in women, a higher risk of hip fracture, most people get enough of the vitamin through their diet. And it's not clear whether there is a benefit from supplementation: results from clinical studies on vitamin K supplementation for preventing bone loss or reducing coronary artery calcification have been mixed.

The Review explains the clinical evidence for vitamin K, how to get vitamin K from foods, how to choose the best vitamin K supplement and dosage based on your needs, and difference in potency among the popular forms of vitamin K, including vitamin K1 and two forms of vitamin K2 -- menaquinone-4 (MK-4) and menaquinone-7 (MK-7). It also provides information about drug interactions with vitamin K supplements and other safety concerns.'s Vitamin K Supplements Review is available online (at and includes test results and quality comparisons for the following twelve products, including eight supplements selected for testing by and four others which passed the same testing through CL's voluntary Quality Certification Program: AdvoCare Calcium Plus, AlgaeCal Plus, Carlson Vitamin K2, Doctor's Best Artery Prime With MenaQ7, Garden of Life Vitamin Code Raw K-Complex, GNC K-2, Healthy Origins Natural Vitamin K2 As MK-7, Jarrow Formulas Bone-Up, Nature's Way Alive Calcium Bone Formula, NOW Vitamin D-3 & K-2, USANA Vitamin D, and Viactiv Calcium Plus D - Milk Chocolate.

Founded in 1999, is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Membership to is available online and provides immediate access to reviews of more than 1,000 products from over 400 brands. The company is privately held and based in Westchester, New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.

— END —

back to top

Members of the media contact may contact or call the main number (914-722-9149). Please include the name of your news organization when contacting us.