Effect on bone anabolic markers of daily cheese intake with and without vitamin K(2): a randomised clinical trial

BACKGROUND: Daily intake of 57 g Jarlsberg cheese has been shown to increase the total serum osteocalcin (tOC). Is this a general cheese effect or specific for Jarlsberg containing vitamin K(2) and 1,4-dihydroxy-2naphtoic acid (DHNA)? METHODS: 66 healthy female volunteers (HV) were recruited. By skewed randomisation (3:2), 41 HV were allocated to daily intake of 57 g Jarlsberg (J-group) and 25–50 g Camembert (C-group) in 6 weeks. After 6 weeks the C-group was switched to Jarlsberg. The study duration was 12 weeks with clinical investigations every 6 weeks. The main variables were procollagen type 1 N-terminal propeptide (PINP), tOC, carboxylated osteocalcin (cOC) and the osteocalcin ratio (R(O)) defined as the ratio between cOC and undercarboxylated osteocalcin (ucOC). Serum cross-linked C-telopeptide type I collagen (CTX), vitamin K(2), lipids and clinical chemistry were used as secondary variables. RESULTS: PINP, tOC, cOC, R(O) and vitamin K(2) increased significantly (p<0.01) after 6 weeks in the J-group. PINP remained unchanged in the C-group. The other variables decreased slightly in the C-group but increased significantly (p≤0.05) after switching to Jarlsberg. No CTX-changes detected in neither of the groups. Serum lipids increased slightly in both groups. Switching to Jarlsberg, total cholesterol and low-density lipoprotein-cholesterol were significantly reduced (p≤0.05). Glycated haemoglobin (HbA1c), Ca(++) and Mg(++) were significantly reduced in the J-group, but unchanged in the C-group. Switching to Jarlsberg, HbA1c and Ca(++) decreased significantly. CONCLUSION: The effect of daily Jarlsberg intake on increased s-osteocalcin level is not a general cheese effect. Jarlsberg contain vitamin K(2) and DHNA which increases PINP, tOC, cOC and R(O) and decreases Ca(++), Mg(++) and HbA1c. These effects reflect increased bone anabolism and a possible reduced risk of adverse metabolic outcomes. TRIAL REGISTRATION NUMBER: NCT04189796.