The effect of different meals on the absorption of stable isotope-labelled phylloquinone.
Few studies have investigated the absorption of phylloquinone (vitamin K1). We recruited twelve healthy, non-obese adults. On each study day, fasted subjects took a capsule containing 20 microg of 13C-labelled phylloquinone with one of three meals, defined as convenience, cosmopolitan and animal-oriented, in a three-way crossover design. The meals were formulated from the characteristics of clusters identified in dietary pattern analysis of data from the National Diet and Nutrition Survey conducted in 2000-1. Plasma phylloquinone concentration and isotopic enrichment were measured over 8 h. Significantly more phylloquinone tracer was absorbed when consumed with the cosmopolitan and animal-oriented meals than with the convenience meal (P = 0.001 and 0.035, respectively). Estimates of the relative availability of phylloquinone from the meals were: convenience meal = 1.00; cosmopolitan meal = 0.31; animal-oriented meal = 0.23. Combining the tracer data with availability estimates for phylloquinone from the meals provides overall relative bioavailability values of convenience = 1.00, cosmopolitan = 0.46 and animal-oriented = 0.29. Stable isotopes provide a useful tool to investigate further the bioavailability of low doses of phylloquinone. Different meals can affect the absorption of free phylloquinone. The meal-based study design used in the present work provides an approach that reflects more closely the way foods are eaten in a free-living population.
Jones
Kerry S
KS
MRC Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge CB1 9NL, UK. kerry.jones@mrc-hnr.cam.ac.uk
Bluck
Les J C
LJ
Wang
Laura Y
LY
Stephen
Alison M
AM
Prynne
Celia J
CJ
Coward
W Andy
WA
D000328:Adult; D001682:Biological Availability; D002247:Carbon Isotopes; D018592:Cross-Over Studies; D004032:Diet; D005260:Female; D005504:Food Analysis / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D010837:Vitamin K 1 / Q000032:analysis / Q000097:blood*; D014815:Vitamins / Q000032:analysis / Q000097:blood*; D055815:Young Adult
D002247:Carbon Isotopes; D014815:Vitamins; D010837:Vitamin K 1