Forty-two days of daily intake of vitamin K2 from softgels or from fortified yogurts resulted in significant increases in plasma vitamin K2 levels, with the greatest increases seen in a yogurt fortified with K2 (MenaQ7, NattoPharma), vitamins C and D3, magnesium and omega-3s.
Scientists from the R&D Group VitaK at Maastricht University and FrieslandCampina report their findings in the European Journal of Clinical Nutrition. The study was sponsored by FrieslandCampina
Commenting on the study’s findings, Hogne Vik, chief medical officer with NattoPharma, said: “This important study validates obtaining Vitamin K2 from food sources is essentially equivalent to Vitamin K2 delivered in supplements.
“Clearly getting Vitamin K2 from diet is ideal, be it cheese, natto, or enriched yogurts. However, as most Western populations are deficient in this essential nutrient, they are not getting enough from diet, making supplementation a viable alternative.
“This study further affirms that MenaQ7 is a safe and effective as either a supplement or a functional food,” adds Vik. “We see this as support for further exploring the use of MenaQ7 in yogurt and other dairy products so we can reach an even wider audience.”
K forms
There are two main forms of vitamin K: phylloquinone, also known as phytonadione, (vitamin K1) which is found in green leafy vegetables such as lettuce, broccoli and spinach, and makes up about 90% of the vitamin K in a typical Western diet; and menaquinones (vitamins K2), which make up about 10% of Western vitamin K consumption and can be synthesized in the gut by microflora.
Menaquinones (MK-n: with the n determined by the number of prenyl side chains) can also be found in the diet; MK-4 can be found in animal meat, MK-7, MK-8, and MK-9 are found in fermented food products like cheese, and natto is a rich source of MK-7.
Study details
Led by Dr Cees Vermeer, the researchers recruited 107 healthy men and postmenopausal women aged between 45 and 65 to participate in their study. The volunteers were randomly assigned to one of three groups: The first group consumed yogurt fortified with vitamins C, D3 and K2, magnesium and omega-3s (Kplus); the second group received yogurt fortified with K2 only, and the third group received vitamin K2 softgels. The daily K2 dose from each intervention was about 60 micrograms.
After 42 days of intervention, results showed that circulating MK-7 increased in all three groups with the greatest increase in the Kplus group than in with the softgels. There were no significant differences in MK-7 levels between the two yogurt groups.
Markers for vitamin K status [uncarboxylated osteocalcin (ucOC) and desphospho-uncarboxylated matrix Gla-protein (dp-ucMGP)] were also measured and found to be significantly lowered after consumption of the MK-7 products, “reflecting vitamin K status improvement from both delivery methods”, wrote the researchers.
“This is the first study demonstrating higher MK-7 steady-state concentrations after intake of a fortified food than a standard food supplement in a direct comparison,” wrote Dr Vermeer and his co-authors.
“In conclusion, dairy matrix and nutrient composition may affect MK-7 delivery and improvement of vitamin K status. Yogurt fortified with MK-7 is a suitable matrix to improve the nutritional status of this fat-soluble vitamin.”
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1038/ejcn.2016.3
“Steady-state vitamin K2 (menaquinone-7) plasma concentrations after intake of dairy products and soft gel capsules”
Authors: M.H.J. Knapenm et al.