The aim of this study is to assess the effect of supplementation of vitamin K2 (menaquinone, MK-7) and cholecalciferol (inactive vitamin D) on circulating levels of calcification regulators and to assess their safety in pediatric patients on regular hemodialysis patients.

Vascular calcification occurs in more than half of chronic renal failure patients, which mainly appears in the large and medium size arteries [3, 4]. It seems that vas¬cular calcification is caused by dynamic imbal-ance of intravascular calcium and phosphorus. However, more and more studies pointed out that vascular calcification were related with local cell's function and biological characteris¬tics.

The aim of this study is to assess the effect of supplementation of vitamin K2 (menaquinone, MK-7) and cholecalciferol (inactive vitamin D) on circulating levels of calcification regulators and to assess their safety in pediatric patients on regular hemodialysis patients.

Inclusion criteria:

• Patients aged 6-18 years
• Patients on hemodialysis since 3 months or longer
• Hemodialysis frequency 3 times or more weekly

Exclusion criteria:

• Patients with life expectancy < 3 months
• Patients taking warfarin
• Patients with known intestinal malabsorption