Vitamin K - Vital for Bone Health
You may know that for strong bones, it’s essential to get enough calcium and vitamin D in your diet. But did you know vitamin K is also important for bone health? We don’t hear as much about this micronutrient, but it plays a critical role in guiding calcium into the bone. Let’s delve deeper into this.
What is vitamin K and how does it work?
First, let’s review what vitamins do for us. Even though we consume them through food sources, vitamins do not actually provide calories for the body. They act as intermediaries to facilitate the myriad chemical reactions that are constantly occurring to keep our bodies humming like a fine tuned machine. Without these “co-factors” as they are called, the system breaks down.
So what type of processes is vitamin K important for? Vitamin K is actually a group of fat-soluble vitamins that aid primarily with blood coagulation and the absorption of calcium into bones. If vitamin K levels are low, blood clotting is impaired and life threatening bleeding can occur. Additionally, bones can weaken because the body is not able to move calcium out of the bloodstream and into bones. Having extra calcium in the circulation can further result in calcification of arteries and other tissues.
Now that we have established WHY vitamin K is important, let’s look at how to make sure we get enough of it!
What are good food sources of vitamin K?
Vitamin K1 is the primary form that we obtain in our diet, and it is found largely in green leafy veggies. These include kale, spinach, collards, broccoli, asparagus, and parsley. Having healthy gut bacteria is important as well, because our bodies synthesize other forms of vitamin K through our gut flora. Consuming probiotic foods and supplements helps maintain these good bacteria. (Check out this post for more information on probiotics.)
How much should we get in our diet?
The good news is that most of us get plenty of vitamin K through our diet and don’t require supplementation. The typical adult requires about 100 - 200 mcg of vitamin K per day. Check out the chart below for the amount of vitamin K in various foods.
Top Vitamin K Rich Foods List
| Food | Serving Size | Amount of Vit K |
|---|---|---|
| Kale | .5 cup | 510 mcg |
| Spinach | .5 cup | 444 mcg |
| Swiss Chard | .5 cup | 285 mcg |
| Broccoli | 1 cup | 220 mcg |
| Brussels Sprouts | 1 cup | 218 mcg |
| Scallions | .5 cup | 103 mcg |
| Prunes | .5 cup | 52 mcg |
| Green peas | 1 cup | 35 mcg |
| Dried basil | 1 Tbsp | 35 mcg |
We also mentioned above that vitamin K is a fat-soluble vitamin - this means that it is best absorbed in the presence of fats. So when you eat that kale salad, don’t forget to drizzle it with olive oil!
What are signs of low vitamin K?
Healthy adults rarely have a problem with vitamin K deficiency. Those at risk include:
-Newborns (who are given a vitamin K shot at birth to reduce the risk of complications)
-Those on long term antibiotic therapies (because the bacteria in the colon may have been affected and do not produce sufficient quantity of vitamin K2)
-Those with malabsorption diseases such as Crohn’s disease, celiac disease, or ulcerative colitis
-Malnutrition caused by alcoholism or anorexia; or as a result of certain medications like warfarin, an anti clotting drug.
The main sign of deficiency is heavy bleeding or easily bruising.
