Vitamin K2: the nest blockbuster supplement?(SUPPLEMENTS: CHECK OUT)

Researcher in Europe are focusing attention on a member of the vitamin K family that seems to deliver significant bone and heart benefits to supplement users.

The nutrient is a subtype of vitamin K2 called MK-7. "It has all the makings of becoming a future nutritional blockbuster," says Connecticut-based cardiologist and nutrition expert Stephen T. Sinatra, MD.

K2 helps put calcium in the bones, where you want it, and keeps it out of your artery walls, where you definitely don't want it, he says. "K2 could be a doctor's dream--a double-barreled protector against osteoporosis and arterial calcification, a common contributor to dangerous, vulnerable plaques prone to rupture and a cause of heart attacks and stroke."

Most supplement users are vaguely familiar with vitamin K, a nutrient found in green leafy vegetables that has been synthesized as an ingredient in supplements. Discovered by Danish scientists in 1929, Vitamin K plays a vital role in the coagulation of blood. In fact, its name comes from the Danish word koagulation.

Vitamin K2 has a somewhat different chemical structure from vitamin K1, along with a growing reputation to impact both bone and arterial health. K2 serves as a critical partner in the body's construction of healthy bones. The body uses a protein called osteocalcin to carry calcium from the blood and knit it into the bone matrix. Without enough K2, the calcium becomes deposited in arterial walls, where it doesn't belong.

Beneficial bacteria in our intestines are able to produce a limited amount of K2 from vitamin K. Another source is food. The richest concentration of K2 is found in natto, a Japanese fermented soybean dish. And it's interesting to note that in Tokyo, where natto is very popular, there is a low incidence of osteoporosis compared to areas of Japan were natto is less popular.

However, before you rush out to an Asian grocer to stock up ...