Answer :Sarah L. Booth, PhD, director of Tufts HNRCA Vitamin K Laboratory, responds: Currently the clinical trial data do not support a protective effect of vitamin K2 on prevention of bone loss. The only benefits have been observed among osteoporotic patients with more than four previous factures. Therefore supplementation is not likely to have beneficial effects. Having said that, should one choose to take it, there are no reported side effects for individuals taking vitamin K2 in doses of 5,000 micrograms/day (5 milligrams) for up to four years.
