Assessment of phylloquinone and dihydrophylloquinone dietary intakes amonga nationally representative sample of US consumers using 14-day food diaries

Objective To estimate dietary intakes of phylloquinone and dihydrophylloqui none in a representative sample of the American population using 14-day foo d diaries. Design Vitamin K food composition data were applied to 14-day food diaries completed by a nationally representative sample of approximately 2,000 hous eholds that participated in a Market Research Corporation of America menu c ensus survey between July 1991 and June 1992. Dietary intakes were estimate d for phylloquinone and dihydrophylloquinone. Subjects Subjects were 4,741 men, women and children with demographic chara cteristics similar to those of the US census population. Statistical analysis performed Descriptive statistics and 8-sample t tests. Results Mean reported intakes of phylloquinone among adults increased with age. Men and women in the 18- to 44-year-old groups reported mean phylloqui none intakes below the current Recommended Dietary Allowance for vitamin K. Of all study participants, 99.3% reported consumption of dihydrophylloquin one during the 14 days of diet recording; reported intakes peaked before th e age of 6 years; after the age of 6 years intakes were constant. Applications The Market Research Corporation of America data provide a refe rence range for dietary intakes of 2 forms of vitamin K in the US diet: phy lloquinone and dihydrophylloquinone. Given the putative role of vitamin K i n bone mineralization, low intakes of phylloquinone reported among young ad ults highlight the need to educate the US population about the requirement for and sources of vitamin K. The abundance of dihydrophylloquinone in the US diet suggests the need for study of its biological activity relative to phylloquinone.