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Low vitamin K1 intakes have been associated with low bone mineral density in women and reduced bone turnover in girls. No European data exist on the relationship between vitamin K1 and serum undercarboxylated osteocalcin (ucOC), an indicator of K1 status in adolescents. The aim of the current study was to assess intakes of vitamin K1 in relation to serum ucOC status in Irish girls. A detailed dietary history method, which measured habitual intakes from a typical 14-day period, was used to estimate vitamin K1 intakes in 18 girls aged 11-13 years. Recently compiled and validated food composition data for vitamin K1 were used to determine vitamin K1 intakes. An enzyme immunoassay was used to measure ucOC in fasting serum samples. The mean (+/- SD) intake of vitamin K1 in the girls was 72.4 microg/day (SD 34.4). Vegetables (particularly broccoli, composite dishes, and lettuce) contributed 53% of total vitamin K1 intakes. Thirty-Seven percent of the girls failed to meet the current U.S. adequate intake for adolescents of 60 microg/day vitamin K1. Serum ucOC levels were inversely related to body weight-adjusted vitamin K1 intakes, controlling for energy intake (partial correlation r = -0.538; p = 0.026). The data indicate that large-scale studies to examine relationships between vitamin K1 (and green vegetable) intakes and bone growth and development in adolescents are warranted.

Dietary vitamin K1 (phylloquinone) levels that are sufficient to maintain normal blood coagulation may be sub-optimal for bone, and habitual low dietary intakes of vitamin K may have an adverse effect on bone health. The objective of the present study was to measure the intake and adequacy of phylloquinone intake and the contribution of foods to phylloquinone intake in a nationally representative sample of Irish adults. The North/South Ireland Food Consumption Survey database was used, which contains data collected using a 7 d food diary in a randomly selected sample of Irish adults aged 18-64 years (n 1379; 662 men and 717 women). Phylloquinone intakes were estimated using recently compiled food composition data for phylloquinone. The mean daily intake of phylloquinone from food sources was 79 (SD 44) microg. Intakes were significantly higher (P<0.001) in men than in women at levels of 84 and 75 microg/d. The main contributors to phylloquinone intakes were vegetables (48 %), particularly green vegetables (26 %). Potatoes (including chipped and fried potatoes), dairy products and fat spreads contributed 10 % each and meat contributed 8 %. In men, social class and smoking status influenced phylloquinone intakes. Of the population, 52 % had phylloquinone intakes below 1 microg/kg body weight and only 17 % of men and 27 % of women met the US adequate intakes of 120 and 90 microg/d, respectively. The present study shows that habitual phylloquinone intakes in Irish adults are low, which may have implications for bone health.