PLT's new offering - of which it is the exclusive US distributor - is derived from natto, a fermented soy food eaten in Japan, consumption of which has been credited with greater rates of bone health and reduction of risk factors in the Japanese population.
Vitamin K is considerably less well-known than vitamins A to E, but it has been shown to play a role in bone health as it influences the secondary modification of osteocalcin, a protein needed to bind calcium to the bone matrix.
Some large human studies have tested the bone health benefits of calcium alone, calcium plus vitamin D and calcium plus vitamin D plus vitamin K. The latter has shown the best effect on osteoporosis; its mechanism is different from, but synergistic with, the other two. (Bolton Smith et al, Ann Nutr Metab 2001; 45, p 246; Braam et al, 2003, Calcif Tissue Int 72).
PLT has only just begun publicising its latest product, but it is aiming to build greater awareness of the benefits of natural K2 in the supplements industry, with consumer awareness to follow.
There are two different molecular forms of vitamin K - K1 (phylloquinone) and K2 (menaquinones).
The former is found in green leafy vegetables such as lettuce, broccoli and spinach, but it is tightly bound to the chloroplasts and humans are not able to absorb it very well.
The latter, meanwhile, is much rarer, and is further subdivided into a number of different forms, abbreviated as MK-n. MK-4 is only found in nutritionally significant amounts in meat and liver. MK-7 to -9 is primarily synthesized by bacteria and is found in fermented products like cheese, cheese curd and natto.
While both K1 and K2 have been shown to play a role in bone health, only K2 has been seen to have additional cardiovascular by promoting promotes matrix Gla-protein, which inhibits vascular calcification.
"Natural vitamin K2 helps keep calcium in the bones and out of the arteries," says PLT.
There are some synthetic versions of K2, called menaterenone-4, on the market; but PLT's natural form, MK-7, has been shown to have a considerably longer half-life than the menaterenone-4, remain in the body in measurable values for as long as 72 hours.
K1 is rapidly cleared by the liver during the first eight hours. Moreover, just 45 micrograms of natural K-7 is needed to produce the same effect as 45 milligrams of synthethic MK-4.
H Scott Rosenbush, business manager, botanicals at PLT, told NutraIngredients-USA.com that synthetic K2 may be cheaper than natural K2, "but is clearly less effective".
He said PLT expects its natural K2 to be well received for a number of reasons, the first of which being "the growing interest in bone health supplements as baby boomers approach the age where they should be concerned about these things".
Rosenbush also believes that it will do well given the demand for cardio-protective products.
"The story plays perfectly into both applications, and is supported by the natural claim which, in itself, is not enough to carry the day."
Natural K2 from natto, known as Natto K2, has previously been available in the US through Natural Inc, the US-based subsidiary of Norway's Natural group.