lower than the median intake of premenopausal women (approximately 85 to 90 μg/day) (Appendix Table C-10).

Although the phylloquinone content in maternal milk can be increased after treatment of mothers with pharmacological doses of vitamin K (Greer et al., 1997; Haroon et al., 1982; von Kries et al., 1987b), results from Greer and coworkers (1991) suggest that vitamin K content of milk is little affected by intake of lactating women who consume typical diets. Because vitamin K is not significantly secreted in milk, there is no evidence to suggest that the AI for lactating women should be different from that for nonlactating women. Therefore, the AI is the same as for nonpregnant women.

Early data obtained by chick bioassay on the vitamin K content of foods were unreliable and a limited number of foods were assayed. Over the last decade, rapid and reliable chromatographic procedures for vitamin K have been developed, and data for the phylloquinone content of most commonly consumed foods are available (Booth et al., 1995). Only a relatively small number of food items (Table 5-3) contribute substantially to the dietary phylloquinone intake of most people. A few green vegetables (collards, spinach, and salad greens) contain in excess of 300 μg of phylloquinone/100 g, while broccoli, brussels sprouts, cabbage, and bib lettuce contain between 100 and 200 μg of phylloquinone/100 g. Other green vegetables contain smaller amounts. Plant oils and margarine are the second major source of phylloquinone in the diet. The phylloquinone content of plant oils is variable, with soybean and canola oils containing greater than 100 μg of phylloquinone/100 g. Cottonseed oil and olive oil contain about 50 μg/100 g, and corn oil contains less than 5 μg/100 g. Prepared foods contain variable amounts of vitamin K depending on their content of green vegetables and the source and amount of oil used in their preparation. Information relative to the important food sources of vitamin K for infants