OBJECTIVE Osteopenia is a common complication of juvenile idiopathic arthritis (JIA). In adults, low bone density and increased fracture risk are associated with low vitamin K status of bone. The vitamin K-dependent protein osteocalcin plays an important role in bone metabolism. Its activity depends upon post-translational carboxylation in which vitamin K is an essential co-factor. Hence, vitam...

OBJECTIVES Vitamin K has bone and cartilage effects, and previously shown to be associated with radiographic osteoarthritis. We evaluated vitamin K's effect on hand osteoarthritis in a randomised controlled trial. METHODS This was an ancillary study to a randomised controlled trial assessing the effects of phylloquinone supplementation (vitamin K arm) versus placebo on bone loss and vascular ...

Bacteroides melaninogenicus requires vitamin K for normal growth. Cells incubated in a vitamin K-free medium form defective cell envelopes. Studies with vitamin K-grown "K(+)" and vitamin K-depleted "K(-)" cells showed that [(14)C]choline and [(14)C]glycerol were not taken up, but several amino acids and acetate were incorporated to the same degree by both types of cultures. However, K(-) cells...

BACKGROUND For children and adolescents with cystic fibrosis (CF) and pancreatic insufficiency, the efficacy of routine vitamin K supplementation to normalize vitamin K status remains unclear. OBJECTIVE This study examined and determined predictors of vitamin K status in subjects aged 8-25 y with CF and pancreatic insufficiency taking various vitamin K supplements. DESIGN In 97 subjects, se...