46F-14 |
Phylloquinone (Vitamin K) content of vegetables and vegetable products |
D. B. HAYTOWITZ1, J. Peterson2, and S. Booth2. (1) Nutrient Data Laboratory, USDA-ARS, B-005, Rm. 307A, BARC-West, 10300 Baltimore Ave., Beltsville, MD 20705, (2) Vitamin K Laboratory, Jean Mayer Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111 Phylloquinone (Vitamin K) is involved in blood coagulation. It may also play a role in protecting against osteoporosis as patients with reduced bone mineral density have lower levels of circulating phylloquinone. Vegetables have been recognized as important sources of this nutrient. However, existing values are available for a relatively small number of vegetables. The objective of this research is to generate nationally representative vitamin K values in foods, which will update and expand the USDA vitamin K database, first released in 1994. This report will focus on the data for approximately 25 vegetables and vegetable products. Sample units were collected at 12 locations in the US. For fresh produce, these were composited to form four regional composites. For vegetable products, several brand-specific national composites were produced. The composites were shipped to the Vitamin K Laboratory at the Jean Mayer Human Nutrition Research Center on Aging for analysis. Phylloquinone was determined by reversed-phase HPLC with fluorescence detection. Leafy greens including cooked spinach (544 mcg/100g), green leaf lettuce (269 mcg/100g) and broccoli raab (215 mcg/100g) were among the best sources. Other green vegetables [e.g. broccoli (117 mcg/100g) and butterhead lettuce (102 mcg/100g)] were also good sources, while relatively small amounts were found in root vegetables like carrots (21 mcg/100g) and cooked potatoes (4 mcg/100g). Based on these analysis, there are more dietary sources of vitamin K in the U.S. food supply than previously thought. The values on the phylloquinone content of vegetables, and those for other foods, will be added to USDA Databases. These values will enable investigators to monitor dietary intakes of phylloquinones and for the first time to assess the impact of vitamin K intake on specific health conditions.
Session 46F, Nutrition
|