Vitamin K’s potential for slowing progression of osteoarthritis

Be sure to load your grocery cart with leafy green vegetables, broccoli and Brussels sprouts.  These foods rich in vitamin K may role a pivotal role in keeping joint cartilage healthy.

It is being suggested by preliminary studies that individuals who consume adequate amounts of vitamin K may experience a slowing progression of the most common form of arthritis, osteoarthritis (OA).  Around 30 million Americans have OA, a disease that damages the slippery tissue that covers the ends of bone in a joint allowing them to rub together.  This results in pain, swelling, and loss of motion of the joint which over time could cause the joint to lose its normal shape. 

Currently, nonsurgical options for treating osteoarthritis include maintain a healthy body weight, physical therapy, and being physically active.  But beyond that, doctors have few other options in preventing or treating it beyond symptom control. 

This is why new studies are showing promise in possible dietary interventions in which vitamin K appears to be the leading nutritional star. 

What to know about vitamin K

Vitamin K’s (the “K” comes from the German word for “coagulation”) discovery came about due to its ability to clot blood, protecting you from excessive bleeding after an injury.  Anyone taking a blood thinner such as warfarin (Coumadin) need to limit their intake of vitamin K as too much could alter the intended effects of warfarin. 

Vitamin K is present in multiple organs and tissues, including the heart, liver, and pancreas.  The study specifically looking at vitamin K’s possible connection to slowing OA progression is researching the nutrient’s role in helping the body prevent damaging buildup of calcium in joint cartilage, called calcification.

It is believed that vitamin K may work with vitamin D to prevent calcification which could imply that an overall healthy diet may help people with knee arthritis to experience less pain and disability.

In this study, two groups of older adults with an average age of 60 to 75, were evaluated on their daily intake of vitamins D and K based on food questionnaires.  Also assessed was their walking speed and ability to perform chair stands, every year for 4 years.  Another study measured blood levels of vitamin K and D levels and lower-extremity function three times over 4 to 5 years.  Findings showed that people who had adequate levels of vitamin K and D were able to walk usual distances faster and rise from a chair or sit back down again more easily.

As to why having adequate levels of vitamin K and D helped OA, researchers suspected it’s because the vitamins are required to insure the proper functioning of the matrix-Gla protein (MGP), a protein that appears to prevent calcification.  Joint tissue needs vitamin D to make MGP and vitamin K then triggers a biochemical change that makes MGP fully functional.

At this time it is not recommended that anyone should begin taking more than the recommended amounts of vitamin K, which is 90 micrograms (mcg) for women and 120 mcg for men a day, in hopes of enhancing MGP’s protective powers.  It is best to obtain vitamin K by eating green vegetables which provide phylloquinone, the main form of vitamin K found in plant foods. 

The richest sources of vitamin K include the following foods:

·      Kale

·      Collards

·      Spinach

·      Turnip greens

·      Mustard greens

·      Beet greens

·      Cabbage

·      Swiss chard

·      Broccoli

·      Brussels sprouts

·      Scallions

While there is no specific diet for arthritis, it wouldn’t hurt to include more foods that may help inflammation.  Many of these foods are found in the Mediterranean diet pattern, which emphasizes fish, vegetables, and oils.  If surfing the internet for advice on “anti-arthritis” diets, watch out for claims that you should avoid nightshade vegetables like tomatoes, eggplants, and peppers; avoiding acidic foods or beverages; drinking cider vinegar and avoiding dairy foods.  Instead of relying on pseudoscience, talk to your primary care doctor or arthritis specialist for their advice.