Phylloquinone (vitamin K1) intakes and serum undercarboxylated osteocalcin levels in Irish postmenopausal women

Abstract

Low phylloquinone (vitamin K1) intakes have been associated with low bone mineral density in older adults. Phylloquinone intakes and serum undercarboxylated osteocalcin (ucOC) levels were assessed in ninety-seven apparently healthy, free-living Irish women aged 50–75 years. Phylloquinone intakes were estimated using a detailed dietary history, which measured habitual food intakes from a typical 14 d period, and recently published food composition data for phylloquinone. Fasting serum ucOC was measured using an enzyme immunoassay. The median daily intake of phylloquinone in the group from all sources was 108·8 mg and from food sources only was 106·6 mg, indicating that approximately 99% of the phylloquinone came from food. Vegetables and vegetable dishes contributed 67% of the total phylloquinone intake, but further analysis showed that broccoli, cabbage and lettuce were the primary sources, making a total contribution of 44 %. Twenty per cent of the women had a phylloquinone intake below the UK recommendation of 1μg/kg body weight per day and 34% failed to meet the US Adequate Intake value of 90mg/day. Mean serum ucOC levels in the women were 6·2 (SD 1·7) ng/ml and were predicted by phylloquinone intake (β— 22·20, generated from log-transformed phylloquinone intake data; P=4 0·04). On the basis of comparisons with both UK recommendations and US A equate Intakes for phylloquinone, the habitual intakes of phylloquinone in a high proportion of Irish postmenopausal women may not be adequate.