We all know that calcium and vitamin D are often thought as the most important nutrients for bone health. But did you know that vitamin K also play a role in preventing bone loss?
Studies show that enough of this vitamin through food sources is likely needed to prevent excess bone loss and help prevent osteoporosis, but instead vitamin K continues to gain traction in the supplement isles.
In food, vitamin K is synthesized by plants and fount mainly in green leafy vegetables such as spinach, Swiss chard, parsley, kale and broccoli, and some fruits such as kiwi, avocado and grapes, in form of Vitamin K1 or phytonadione. Vitamin K1 is also available in supplement in the United States, by which according to researchers is a better way to absorb vitamin K1 than from food sources.
This vitamin is also one of the few that is produced naturally in the lower gut of humans by bacteria in the colon in the form on vitamin K2 or menaquinone. Vitamin K2 is also found in some animal products such as dairy and fermented foods.
Vitamin K intake requirements are easily met from food. Although dietary sources offer abundant vitamin K, some studies suggest that supplemental “free form” is more readily absorbed by the body due to its bound to compounds within plants. Some terms used on labels include K1 as phylloquione or phytonadione and K2 as MK-4 or MK-7.
According to the Natural Medicines Database, there is “insufficient reliable evidence to rate” vitamin K’s effectiveness in the treatment of osteoporosis. However, there is some promising research about this vitamin that links its abilities to bone health because it supports one of the main proteins that strengthens bones. Some studies suggest that higher vitamin K intake is connected with a lower risk of bone fracture and higher bone mineral density, while others do not show any benefit or effect.
Drug-nutrient interactions of moderate and major effects are important to discuss with patients who are interested in vitamin K supplementation, which includes anti-diabetes drugs, blood thinning medications, the weight-loss drug Orlistat, bile acid medications, certain antibiotics and several vitamins. A tolerable high amounts for K1 and K2 has not been established due to lack of known toxicity, though risk is reportedly low and adverse effects are rare.
Unless patients show vitamin K deficiency, there is still a little evidence that additional vitamin K supplementation is helpful for preventing osteoporosis and fractures. Even though studies show that vitamin K benefits bone health, it is still important to note that other bone building compounds such as vitamin D and calcium are present. Consumers who choose to supplement should discuss with their physicians, use for caution and look for independent quality assessment seals and third-party verification for added safety since dietary supplements do not require FDA approval.