Sl. Booth et al., Assessment of phylloquinone and dihydrophylloquinone dietary intakes amonga nationally representative sample of US consumers using 14-day food diaries, J AM DIET A, 99(9), 1999, pp. 1072-1076
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.