11 June 2009
Vitamin K2 may boost bone health in adolescents
Supplements of vitamin K2 may improve bone health in prepubescent children, and potentially protect them from osteoporosis later in life, says a new study.
Writing in the British Journal of Nutrition, Dutch scientists report that a daily supplement of vitamin K2 in the menaquinone-7 (MK-7) form improved levels of osteocalcin, a vitamin K-dependent protein and is essential for the body to utilise calcium in bone tissue. Without adequate vitamin K, the osteocalcin remains inactive, and thus not effective.
“The present study is the first one to demonstrate that increased vitamin K intake by supplement improves the osteocalcin activity in children,” said Professor Cees Vermeer at the VitaK research center in Maastricht.
“The next step must be that also an effect of MenaQ7 on bone strength or fracture risk is demonstrated in this age group. There is a growing awareness that maximizing bone strength at childhood is an important strategy to prevent osteoporosis at later age,” he added.
Osteoporosis is characterized by low bone mass, which leads to an increase risk of fractures, especially the hips, spine and wrists. An estimated 75 million people suffer from osteoporosis in Europe, the USA and Japan.
Women are four times more likely to develop osteoporosis than men.
Potential reduction of osteoporosis has traditionally been a two-pronged approach by either attempting to boost bone density in high-risk post-menopausal women by improved diet or supplements, or by maximising the build up of bone during the highly important pubescent years.
About 35 per cent of a mature adult's peak bone mass is built-up during puberty.
Professor Vermeer and his cow-workers recruited 55 healthy children to participate in a double-blind, randomised placebo-controlled trial. Children were randomly assigned to receive either dailyMK-7 supplements (45 micrograms, MenaQ7 provided by NattoPharma, Norway), or placebo for eight weeks.
Using the ratio of undercarboxylated osteocalcin (ucOC) to carboxylated osteocalcin (cOC) as a measure of vitamin K status, the researchers found that, in the MK-7 group only, levels of ucOC decreased, and the ratio of ucOC to cOC improved.
No changes were observed in other measures, including bone markers and coagulation parameters.
“The present study indicates that supplementation with MK-7, one of the vitamin K2 species, during 8 weeks reduces the amount of circulating ucOC and thereby improves vitamin K status in healthy prepubertal children,” wrote the researchers.
“Additional dose-finding studies are needed to investigate optimal osteocalcin carboxylation in children. Thereafter, large longitudinal supplementation paediatric trials are required to confirm the beneficial effect of vitamin K supplementation via osteocalcin carboxylation on improved bone mass and diminished fracture risk,” they added.
Source: British Journal of Nutrition