Submitted to: Journal of Lipid Research
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2004
Publication Date: April 15, 2004
Citation: Novotny Dura, J., Kurilich, A.C., Britz, S.J., Baer, D.J., Clevidence, B.A. 2004. Appearance of labeled beta-carotene, lutein, retinol, and phylloquinone in plasma after consumption of isotopically-labeled kale. Journal of Lipid Research 46:1896-903 Technical Abstract: To investigate the bioavailability of nutrients from a green, leafy vegetable, isotopically-labeled kale was produced and used in a human feeding trial. Kale was chosen because of its high content of both beta-carotene and lutein. The kale was grown in a sealed chamber in the presence of carbon-13 dioxide (99% enrichment) to produce fully labeled plants. After harvest, blanched kale (400 g single dose) was ingested by 6 volunteers with 30 g safflower oil. The kale dose supplied approximately 20 mg of both beta-carotene and lutein and 70 micrograms of phylloquinone. Serial plasma samples were analyzed for labeled and unlabeled analytes by LC-MS. Peak concentrations (mean+/-SD) of labeled analytes were found to be as follows: 0.063+/-0.031 micromolar for beta-carotene, 0.077+/-0.029 micromolar for retinol, 0.39+/-0.08 micromolar for lutein, and 1.55+/-0.76 nanomolar for phylloquinone. The inter-individual variability in area under the plasma analyte concentration-time curves were as follows: 41% for beta-carotene, 37% for lutein, 30% for retinol, 67% for phylloquinone. The peak analyte concentrations represented the following percentages of dose: 0.6% for beta-carotene, 3.6% for lutein, 0.7% of molar beta-carotene dose for retinol, and 0.4% of dose for phylloquinone. The isotopic labeling of kale combined with its use in a human feeding trial provides a unique way to examine the comparative bioavailability of nutrients.