Researchers analyzed the nutritional status of these 2 vitamins in postmenopausal women with both normal and low bone mineral density (BMD).

• The women were divided into four groups. One group received 350-400 IU vitamin D3, 80 micrograms Vitamin K1, both of these vitamins, or a placebo.

• At the start of the study, researchers found that the vitamin K status of the women was positively correlated with their BMD.

• Supplementation with vitamin K was able to bring up to normal, the vitamin K status of the women with low BMD.

• Although supplementation with 350-400 IU of vitamin D did improve their vitamin D status, it was not an adequate enough doses to prevent a significant (29%) decline during the winter months in women with low BMD.

Vitamin D status was assessed in the women by measuring the serum levels of 25-hydroxyvitamin D [25(OH)D] and to assess the vitamin K status, the serum carboxylated osteocalcin (%carbOC) was used.

Therefore, as a result of their findings, the researchers note that Dutch postmenopausal women need to be supplemented with more than 400 IU of vitamin D, along with 80 micrograms of vitamin K, to maintain optimal bone health.

European Journal of Clinical Nutrition August 2000; 54, 626-631.

Dr. Mercola's Comments:

Well folks, most of us are at the time of the year where we need to break out the vitamin D supplements. An earlier excellent article on vitamin D stated that vitamin D should not really be called a vitamin since it is closer to a steroid and is not in foods, but made in our skin in response to sunlight. For those of us who live in areas where it is starting to require a coat at this time of year, it will be wise to go on a supplement of vitamin D until next spring, unless you are vacationing where you can get regular doses of sunshine. Vitamin K is an often-overlooked in regard to bone health, where it is very important. The body needs it to manufacture certain proteins that are necessary for bone formation. The best sources of vitamin K are leafy green vegetables. Eggs have some as well. Below are a few examples of the vitamin K content of some good sources. Food Vitamin K (micrograms/100g) Food Vitamin K (micrograms/100g) Collard Greens 440 Cabbage 145 Spinach 380 Olive Oil 55 Salad Greens 315 Asparagus 60 Kale 270 Okra 40 Broccoli 180 Green Beans 33 Brussels Sprouts 177 Lentils 22 Vitamin K is also produced by bacteria in the intestines, which is another reason to maintain a healthy intestinal flora. It is also important to avoid hydrogenated oils (trans fats), as they contain a chemically altered form of vitamin K, which may actually act antagonistically to the naturally occurring form. Related Articles: Rickets Cases Rising in Dark-Skinned Children Vitamin D Urged for Breastfed, Dark-Skinned Infants Sunlight, Vitamin D and Multiple Sclerosis