Eating Green for Healthy Bones

Everyone knows that calcium is needed for healthy bones. You may even know that vitamin D is also needed. But did you know about vitamin K?

Keeping our bones healthy is a complex process. Bones not only hold us upright, they serve as calcium storage facilities. Calcium performs a number of functions including regulating our heart beat, contracting our muscles, and firing up our neurotransmitters. Since calcium is so important to our well being, our bodies have a lot of different ways of regulating where calcium ends up. How much calcium will be absorbed? Vitamin D regulates the creation of calcium receptors for absorption. Will calcium get added to our bones or go elsewhere? Vitamin K makes our bones receptive to incorporating calcium.

Our bones are constantly giving away and storing calcium. The bone cells that build up our bones are called osteoblasts and these bone-building osteoblasts secrete a noncollagen protein called osteocalcin. For calcium to be incorporated into our bones, it must first bind to osteocalcin and osteacalcin must first be modified to allow that binding to occur. The formal term for this modification is gamma-carboxylation. Vitamin K facilitates the gamma-carboxylation, or the modification, of the osteocalcin. Without vitamin K, no calcium can bind to the osteocalcin limiting the amount of calcium transported into the bone matrix.

Recent studies have shown that we may need to eat more vitamin K. Vitamin K is also made by our gut flora which takes care of part of our daily needs – and makes it difficult to estimate the additional amount needed from food.

To maximize vitamin K’s bone-building function, the adequate intake recommendation from food was recently increased to 90 µg (micrograms) per day for adult females and 120 µg per day for adult males. These recommendations may be revised as more data becomes available.

And what’s the best source of vitamin K? Green veggies.

While there is no known toxicity from eating too much vitamin K from foods, you can consume too much from supplements so never take supplements containing more than 1 mg of vitamin K, which is way more than you need anyways. FYI, one microgram = 1,000th of a milligram or 1,000,000th of a gram; 1 milligram = 1,000th of a gram.

To safely and enjoyably increase your vitamin K levels, eat lots of these:


Vitamin K is also vital for blood clotting. Newborns, who are born with sterile guts, are given vitamin K shots to ensure proper blood clotting. Adults on blood thinning medication, such as warfarin, need to consume consistent amounts of vitamin K so that their medication can be set at the most effective dosage.