Dihydro-vitamin K1: primary food sources and estimated dietary intakes in the American diet

Dihydro‐vitamin K1 was recently identified as a dietary form of vitamin K produced during the hydrogenation of vitamin K1‐rich vegetable oils. Dihydro‐vitamin K1 is absorbed, with measurable levels in human plasma following dietary intake. To determine the primary food sources of dihydro‐vitamin K1 in the American diet, 261 foods from the U.S. Food and Drug Administration's (FDA) Total Diet Study (TDS) were analyzed by high‐performance liquid chromatography. Of these foods, 36 contained dihydro‐vitamin K1. Fast‐food items that were otherwise poor sources of vitamin K1, such as french fries and fried chicken, contained appreciable amounts of dihydro‐vitamin K1 (36 and 18 μg/100 g, respectively). These nutrient values were then applied to the FDA TDS consumption model to determine average dietary intake of dihydro‐vitamin K1 in 14 age‐gender groups. With the exception of infants, all age‐gender groups had estimated mean daily dihydro‐vitamin K1 intakes of 12–24 μg, compared to mean daily vitamin K1 intakes of 24–86 μg. The vitamin K1 and dihydro‐vitamin K1 intakes were summed, and the dietary contribution of dihydro‐vitamin K1 was expressed as a percentage of total vitamin K intake. Children reported the highest intakes of dihydro‐vitamin K1 (30% of total vitamin K intake), followed by a progressive decrease in percentage contribution with age. There are currently no data on the relative bioavailability of dihydro‐vitamin K1 but, given its abundance in the American diet, this hydrogenated form of vitamin K warrants further investigation.