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Vitamin K2 (Menaquinone)
Jul 9, 2010

Dear Nelson: Is it possible to measure the Vitamin K2 (menaquinone)in the blood? Should I ask the doctor about it? My doctor discovered my big lack of Vit D because I asked.

Response from Mr. Vergel

Several studies have shown the importance of vitamin K in bone health. by increasing bone mass and reducing bone loss. We do not have any data on vitamin K deficiencies in HIV, however.

Vitamin K is also important to help support proper coagulation (blood clotting). The liver uses vitamin K to synthesize blood-clotting proteins. Without vitamin K, the level of the blood-clotting proteins drops, and clotting time is prolonged. Vitamin K has also been recognized for its role in helping to maintain the health of bones. There are three types of vitamin K:

- Phylloquinone, which was discovered in Denmark and termed vitamin K for the Danish word koagulation, is the natural vitamin K found in alfalfa and other foods. It is known as K1.

- Menaquinone, produced by intestinal bacteria, is K2. Menadione, a synthetic compound with the basic structure of the quinones, is K3.

In Japan, a form of vitamin K2 is recognized as a treatment for osteoporosis. However the long term effects and benefits are unknown and it remains controversial. Data from the 1998 Nurses Health Study found an inverse relationship between dietary vitamin K1 and the risk of hip fracture. After being given 110 micrograms/day of vitamin K, the main results showed that women who consumed lettuce one or more times per day had a significantly lower risk of hip fracture than women who consumed lettuce one or fewer times per week. In addition to this, high intakes of vitamin D but low intakes of vitamin K may still pose an increased risk of hip fracture hinting at a relationship between these two vitamins.

The combination of menaquinne and vitamin D3 has additive beneficial effects on sustaining bone density in the lumbar area and preventing vertebral fractures in postmenopausal women with osteoporosis.

The role of vitamin K in the prevention of arterial calcification is not as well researched. A recent clinical trial of postmenopausal women has implicated phylloquinone deficiency as a risk factor for arterial calcification and has hinted to a connection between the deficiency and osteoporosis. But more data are needed.

The only study done in HIV was a small in-vitro one done in the 80's. It showed that menaquinone induced inhibition of syncytia formation, which is the clumping of CD4 cells that can make them ineffective in fighting HIV. But no other studies have been performed since then.

Vitamin K is found in leafy green vegetables such as spinach, swiss chard, and Brassica (e.g. cabbage, kale, cauliflower, broccoli, and brussels sprouts); some fruits such as avocado and kiwifruit are also high in vitamin K. Two tablespoons of parsley contain 153% of the recommended daily amount of vitamin K. Cooking can reduce the absorption of Vitamin K in the body. For example, cooked spinach has a 5 percent bioavailability of phylloquinone.

It would not hurt to measure Vitamin K levels in your blood, although deficiencies are rare. Let us know if you do decide to do so what your test results are. As I said, Vitamin K has not been explored at all in HIV.


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