Dietary supplementation with a combination of vitamin K with vitamin D and calcium increases bone mineral content in healthy older women: a two-year randomized controlled trial
Based on study:
“Two-Year Randomized Controlled Trial of Vitamin K1 (Phylloquinone) and Vitamin D3 Plus Calcium on the Bone Health of Older Women”
Caroline Bolton-Smith, Marion ET McMurdo, Colin R Paterson, Patricia A Mole, Julia M Harvey, Steven T Fenton, Celia J Prynne, Gita D Mishra, and Martin J Shearer
Journal of Bone and Mineral Research (2007)
22(4):509-19
April
Summary:
Calcium and vitamin D supplementation have been shown to be effective in maintaining bone mineral density (BMD) or in decreasing hip fracture incidence. It is also suggested that vitamin K1 could improve bone health and prevent osteoporosis. This randomized controlled trial was conducted to establish the influence of an extra daily intake of 200 μg vitamin K1 on older women’s bone health. Its aim was also to investigate the interaction with vitamin K, of vitamin D, calcium at additional daily intakes of 400 IU and 1000 mg, respectively. In summary, results indicated that nutritional intakes of vitamin K1, vitamin D and calcium together with dietary supplementation could increase bone mineral content (BMC) where there had been evidence of bone loss at the ultradistal radius. This study suggests that taking a combined supplement may increase BMC in patients with bone loss.
Key words:
Bone health, bone mineral content, bone mineral density, calcium, combined supplementation, dietary supplement, osteoporosis, vitamin D3, vitamin K1
Improving bone health could extend quality of life years. One of the most achievable and sustainable approaches is dietary change. Pathogenesis of hip fracture often occurs in the elderly because of undernutrition. In some studies, calcium and vitamin D supplementation have been shown to be effective in maintaining bone mineral density (BMD) or in decreasing hip fracture incidence. However, not all studies support these benefits. It is suggested that vitamin K could improve bone health and prevent osteoporosis. Vitamin K is a co-factor to convert peptide-bound glutamate residues to γ-carboxyglutamate residues in target proteins that are synthesized by various tissues. These include osteocalcin, which must undergo carboxylation before binding to hydroxyapatite. A high circulating level of undercarboxylated osteocalcin (GluOC) is a risk predictor of bone fractures and a low BMD. Thus, ensuring optimal dietary intakes of vitamin K is important. Circulating GluOC in elderly women also reflects vitamin D status. This study was designed to establish the influence of an extra daily intake of 200 μg vitamin K1 on older women’s bone health. It was also conducted to investigate the interaction with vitamin K, of vitamin D, calcium at additional daily intakes of 400 IU and 1000 mg, respectively.
244 healthy and nonosteoporotic women were assigned randomly to receive either placebo; or 200 μg/day vitamin K1; or 10 μg (400 IU) vitamin D3 plus 1000 mg calcium/day; or combined vitamins K1 and D3 plus calcium. Baseline and 6-month measurements included dual-energy x-ray absorptiometry bone mineral scans of the hip and wrist, markers of bone turnover and vitamin status. Multivariate general linear modeling was used to test supplementation effects.
Results showed that in the combined vitamin K and vitamin D plus calcium group, there was an increase in BMD of 0.8% per year (P < 0.01). In women who had received combined supplementation with vitamin K and D, unadjusted bone mineral content (BMC) at the ultradistal radius also showed a significant increase in bone mineral (P < 0.01). There were significant 2-year rises in BMC in the placebo group, vitamin D group as well as combined vitamin groups. From baseline at the ultradistal radius in the combined vitamin groups, there was an increase in BMD and BMC. The increases in BMD at 18 months and 2 years and in BMC at all visits from 6 months onward were significant. Over 2 years, the absolute concentration of GluOC declined significantly, which was 40%, due to vitamin K supplementation. Serum 25(OH)D increased significantly with a mean increase of 16.7% over 24 months in response to vitamin D supplementation (P < 0.001). However, 25(OH)D declined significantly in the non-vitamin D-supplemented subjects with a mean decline of 17.5% (P < 0.001).
In summary, nutritionally relevant intakes of vitamin K1, vitamin D and calcium together with dietary supplementation could increase bone mineral content.
Reference
- Bolton-Smith C, McMurdo ME, Paterson CR, Mole PA, Harvey JM, Fenton ST, et al. Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women. Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. 2007;22(4):509-19. Epub 2007/01/25.