Increased serum osteocalcin levels and vitamin K status by daily cheese intake

Background: Cheese is a major source of long-chained vitamin K2 variants. How intake of vitamin K2 rich cheese affects vitamin K and osteocalcin has not been studied. The aim was to establish a maximum efficacy dose (MED) after daily intake of vitamin K2-rich cheese (Jarlsberg ® ) based on increase in ratio between carboxylated and undercarboxylated osteocalcin during a five-week diet. Methods: 20 healthy healthy volunteers (HV) were recruited. The daily intake of Jarlsberg ® cheese in the study varied from 20 to 152 g. Clinical investigation was performed initially and after three, four and five weeks with measurement of vital signs, hematological and biochemical variables, carboxylated and undercarboxylated osteocalcin and vitamin K. The ratio OR= carboxylated/undercarboxylated osteocalcin was the main variable. Results: The MED decreased with treatment duration and was estimated to 57 g/day (95% CI: 47-67) after five weeks diet, resulting in a mean OR increase of 30% (95% CI: 23.8-36.8). Both OR and serum osteocalcin followed a quadratic dose response curve. For osteocalcin, a maximal increase of 46% was estimated at 59 g/day for five weeks. The serum content of long-chained vitamin K2 increased significantly with increasing cheese dose. The increase were mainly obtained the first three weeks and kept unchanged the following two weeks. The cheese doses close to the MED caused nearly significant reductions in total cholesterol, LDL-cholesterol, the LDL/HDL ratio and significant reduction in the blood pressures after five weeks diet (p≤0.05). Conclusions: MED of Jarlsberg® cheese was estimated to 57 g/day. Daily intake of Jarlsberg ® cheese increased the osteocalcin level, vitamin K2 and positively affected the lipid patterns and blood pressure.