August 19, 2019

Do You Need Vitamin K Supplements for Your Bone Health?

Understanding the role of this vitamin (and where to find it!)

Vitamin K supplements in foreground with leafy veggies rich in vitamin K in background

You know your body needs calcium and vitamin D for strong, healthy bones. But do you know your bones also need vitamin K? And should you be taking a vitamin K supplement?

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Vitamin K has long been known to play an important role in blood clotting. Recent research has focused on the influence of vitamin K in diseases such as heart disease, osteoporosis, diabetes and cancer. But let’s focus here on bone health.

How does vitamin K help your bones?

“There is scientific rationale for looking at the association between vitamin K, bone density and fracture risk,” says rheumatologist Chad Deal, MD. Vitamin K activates proteins involved in bone formation and mineralization (a process that makes bones strong).

Vitamin K comes in two forms — K1 and K2. Vitamin K1 is found primarily in green, leafy and cruciferous vegetables. Vitamin K2, which is predominantly produced by bacteria, is further divided into subgroups named MK4 to MK13. Foods rich in vitamin K2 include some dairy products, pork, poultry and fermented foods.

Vitamin K2 may have more of a protective effect on bone than vitamin K1. However, deficiencies of both K1 and K2 appear to have a negative effect.

Chart of sources of vitamin k

Not getting enough vitamin K hurts bone health

Several observational studies have found that inadequate intake of vitamin K is linked to low bone density and increased risk for fractures.

Advertisement

A study that analyzed data from the large Nurses’ Health Study found that women who consumed less than 109 micrograms (mcg) of vitamin K per day were more likely to break a hip.

A study of participants (both men and women) in the large Framingham Heart Study also showed a link between low vitamin K intake and increased risk of hip fractures. This study also showed an association between low dietary intake of vitamin K and low bone density in women.

An adequate intake of vitamin K is considered to be 120 mcg for men and 90 mcg for women. A true vitamin K deficiency, which is marked by an inability of blood to clot normally and easy bruising, is rare. “Most people can avoid a deficiency by getting enough vitamin K in their diet,” says Dr. Deal.

Should you take a vitamin K supplement?

Based on the connection between vitamin K and bone health, several studies looked at whether it makes sense for anyone, including people with osteoporosis or at risk for it, to take vitamin K supplements. So far, results have been mixed.

Some studies, many of them conducted in Japan, found that supplementation with vitamin K1 or vitamin K2 improved bone mineral density, and few studies showed a decreased risk of bone fractures. Some subsequent studies found that vitamin K supplementation had no effect on bone mineral density. Many of the studies conducted thus far are limited by flaws in the design or a small number of participants.

Advertisement

Evidence to support vitamin K supplementation is too preliminary and contradictory to make recommendations. The U.S. Food and Drug Administration has not authorized a health claim.

“There is evidence for some positive effect, and there are ongoing studies,” says Dr. Deal.

Vitamin K supplements are relatively safe, and many people take them. People taking blood-thinning drugs, such as warfarin (Coumadin®), should not take vitamin K without consulting their doctor because vitamin K can reverse the effects of these drugs.

This article originally appeared in Cleveland Clinic Arthritis Advisor.

Related Articles

pouring dairy milk into glass
July 12, 2023
4 Benefits of Casein

Protect and build muscle while getting essential amino acids and calcium with this protein

person reading a yogurt cup label
June 12, 2023
Calcium 101: Bone Up on Your Knowledge

This essential mineral is key to healthy bones and teeth, but also plays other important roles

chopped and whole onions on cutting board
May 29, 2023
Stop the Tears: Why Onions Are Good for You

Beyond the tell-tale aroma, onions also provide benefits like strong bones and a healthy heart

foods with fat soluble vitamins
May 16, 2023
Fat-Soluble Vitamins: What They Are and How To Get the Most Out of Them

Vitamins A, D, E and K stay in your body longer and are best eaten with a bit of healthy fat

person taking vitamins from pill organizer
April 18, 2023
Yes, You Can Take Too Much Vitamin D and Vitamin K

It’s always best to talk to a healthcare provider before taking any supplements to avoid toxicity

corn husk silk
April 16, 2023
Can You Eat Corn Silk? 4 Health Benefits of Corn Silk

These silky strands can reduce cholesterol and inflammation, and more

Chicken with blueberry sauce is loaded with vitamin K.
April 11, 2023
Try These 21 Healthy Foods Full of Vitamin K

From leafy greens to heart-healthy oils, the selection is abundant

Kale and other leafy greens.
March 19, 2023
These 11 Foods Are High in Vitamin K2 — But That Doesn’t Mean They’re All Healthy

Vitamin K2 foods aren’t the usual suspects

Trending Topics

White bowls full of pumpkin seeds, dark chocolate and various kinds of nuts
25 Magnesium-Rich Foods You Should Be Eating

A healthy diet can easily meet your body’s important demands for magnesium

Woman feeling for heart rate in neck on run outside, smartwatch and earbuds
Heart Rate Zones Explained

A super high heart rate means you’re burning more than fat

Spoonful of farro salad with tomato
What To Eat If You’ve Been Diagnosed With Prediabetes

Type 2 diabetes isn’t inevitable with these dietary changes

Ad