British Journal of Nutrition

Research Article

Phylloquinone (vitamin K1) intakes and food sources in 18–64-year-old Irish adults

Paula Duggana1, Kevin D. Cashmana1a2, Albert Flynna1, Caroline Bolton-Smitha3 and Máiréad Kielya1 c1

a1 Department of Food and Nutritional Sciences, University College Cork, Cork, Republic of Ireland

a2 Department of Medicine, University College Cork, Cork, Republic of Ireland

a3 MRC Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge CB1 9NL, UK


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) μg. Intakes were significantly higher (P>0·001) in men than in women at levels of 84 and 75quest;μgsol;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 μg/kg body weight and only 17% of men and 27% of women met the US adequate intakes of 120 and 90 μg/d, respectively. The present study shows that habitual phylloquinone intakes in Irish adults are low, which may have implications for bone health.

(Received August 26 2003)

(Revised February 04 2004)

(Accepted March 02 2004)


c1 *Corresponding author: fax +353 21 4270244, Email