Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women

Bolton-Smith C, McMurdo ME, Paterson CR, Mole PA, Harvey JM, Fenton ST, et al.

Published in J Bone Miner Res, Vol. 22 (4), pp. 509-19

Methodology

Two-year double-blind, placebo-controlled trial in 244 healthy, non-osteoporotic Scottish women aged 60 or over, randomised to placebo, 200 mcg/day vitamin K1, 400 IU vitamin D3 plus 1,000 mg calcium, or all three combined. Bone density and content of the hip and wrist by DXA.

Key Findings

Vitamin K1 alone did not change bone density at any site. Women taking vitamin K1 together with vitamin D3 and calcium had a significant, sustained rise in bone density and content at the ultradistal radius only, not at the hip. Vitamin K1 raised serum vitamin K1 by 157% and cut undercarboxylated osteocalcin by 51%.

Conclusions

The authors describe a modest synergy of vitamin K1 with calcium and vitamin D at one wrist site, and suggest the effect could be reached through diet rather than supplements.