SUPPORTS

Bone Health by Promoting Carboxylation of Bone Proteins.

SUPPORTS

Healthy Blood Clotting.

SUPPORTS

Cardiovascular Health by Affecting Arterial Calcium Deposits.

VITAMIN D (AS D3)

Although vitamin D3 (cholecalciferol) is made in the skin when 7-dehydrocholesterol reacts with sunlight, many things affect the degree to which this biosynthesis occurs, including time of day, seasons, location, smog/pollution, clothing, shade of skin (darker skin requires more sun), and sunscreen use. Low-cholesterol diets and certain cholesterol therapies can also affect vitamin D formation. By some estimates, one billion people worldwide have vitamin D deficiency or insufficiency.[18] The body needs vitamin D to absorb calcium, and the importance of vitamin D in skeletal health and bone density is well-established. Without adequate absorption, the body must take calcium from its stores in the skeleton, which weakens existing bone and prevents the formation of strong, new bone. Researchers suggest that vitamin D supplementation may decrease bone turnover and increase bone mineral density.[19] A pooled analysis evaluating 11 randomized, double-blind, placebo-controlled trials supported this analysis. It concluded that vitamin D supplementation (> 800 IU daily) was favorable in maintaining hip and nonvertebral bone integrity in individuals aged 65 and older.*[20] Although D2 and D3 are similar biochemically, one study demonstrated D3 to be approximately 87% more potent in raising and maintaining serum calcidiol (the body’s storage form) concentrations and in producing two- to threefold greater storage of vitamin D than did equimolar D2.*[21] † The cOC:ucOC ratio can be used as a determinant of vitamin K status.

MK-7 BIOAVAILABILITY INCREASES EXTRAHEPATIC TISSUE UTILIZATION

Schurgers et al conducted human studies to compare the in vivo properties of orally administered K1 and MK-7. The results supported better bioavailability and utilization of MK7. Expressed as AUC96, MK-7 demonstrated a six-fold better half-life, a seven- to eight-fold higher doseresponse level, and a three times higher carboxylated to uncarboxylated osteocalcin ratio (cOC:ucOC† ). Furthermore, on a molar basis, MK-7 is a three-to-four times more potent antidote for oral anticoagulation than is K1. Researchers note that, aside from sensitive individuals, “MK-7 supplements containing more than 50 mcg/d may interfere with oral anticoagulant treatment, whereas doses of at least 50 mcg are not likely to affect the INR value in a relevant way.”[2]

BONE BENEFITS

Among the dietary factors critical to bone health, vitamin K has emerged as a key player. Vitamin K is believed to be necessary for bone mineralization. Through carboxylation, vitamin K activates osteocalcin, the protein needed to bind calcium to the mineral matrix in bone.[6] Several studies have demonstrated the efficacy of MK-7 (e.g., doses of 45-90 mcg/d) to increase osteocalcin carboxylation and to increase the cOC:ucOC ratio. A high cOC:ucOC ratio is associated with bone health.[1,2,4] A recent in vitro study also showed an osteogenic effect of MK-7 administration on human mesenchymal cell differentiation.[6] In addition, the vitamin may protect bone integrity by reducing the synthesis of prostaglandin E2 or interleukin-6 by osteoclasts.[7] Animal and human studies have demonstrated a significant beneficial effect of MK-7 supplementation on bone health.[8-10] Vitamin K and vitamin D share some similar characteristics and are believed to act synergistically.*[11]

CARDIOVASCULAR AND OTHER HEALTH BENEFITS

Vitamin K benefits cardiovascular health by participating in the carboxylation of matrix GLA protein (MGP), a protein regarded to be the most potent inhibitor of arterial calcification. Researchers have demonstrated that supplementation with vitamin K reduces arterial calcium deposits[1,3,12] and that long-term intake of long-chain menaquinones is inversely correlated with calcium accumulation in arteries.*[5] Vitamin K has specific receptor binding sites that allow it to regulate gene activity.[13] Besides its gene-mediating effects upon critical proteins, the vitamin can also bind with the steroid and xenobiotic receptors and influence their expression.[14] In addition, vitamin K also demonstrates antioxidant activity[15]; reduces levels of certain markers, such as acute phase reactants (e.g., C-reactive protein)[16]; and participates in the induction of apoptosis.*[17]