Vitamin Okay at a Look
Vitamin Okay has two varieties: K1 and K2.
- K1 (phylloquinone) is plentiful in plant meals, particularly leafy greens. No must complement.
- K2 (menaquinones) is scarce in plant meals. Supplementation could also be acceptable on a plant-based food plan.
Vitamin Okay is vital for the next causes:
- Important for blood coagulation and bone metabolism.
- Permits the physique to make the most of the calcium wanted for bone and tooth formation.
- Helps stop the calcification of sentimental tissue.
- Low ranges are related to the next threat of hip fracture or low bone mineral density (BMD).
- Greater consumption is related to a decrease threat of bone fractures.
Vitamin Okay additionally permits the physique to make the most of the calcium wanted for bone and tooth formation and helps stop calcification of sentimental tissue.1,2 Many research have related low vitamin Okay standing with the next threat of hip fracture or low bone mineral density (BMD),2-5 and, conversely, greater vitamin Okay consumption is related to a decrease threat of fractures.6
Are There Variations Between K1 and K2?
Vitamin Okay exists in two main varieties in nature, K1 and K2. Vitamin K1 (additionally known as phylloquinone) is straightforward to acquire when following a Nutritarian food plan since it’s plentiful in leafy inexperienced greens, akin to kale, collards, spinach, and mustard greens. Most dietary vitamin Okay is K1, and as much as 25 % of vitamin Okay in a typical food plan could come from K2.2 Vitamin K2 (a number of completely different substances known as menaquinones) is produced primarily by micro organism, and is scarce in plant meals. K2 is harder to get from a Nutritarian food plan since it’s primarily present in animal merchandise, notably in darkish meat rooster, pork, and fermented meals like cheese and yogurt. The human physique can synthesize some K2 from K1, and intestinal micro organism can produce some K2, however these are small quantities, and it’s unclear whether or not any vital quantity is absorbed after manufacturing by the microbiome.7
The proof is inconclusive on whether or not there are advantages of vitamin Okay particular to K1 or K2. There’s some proof that K2 is extra bioavailable, and has greater useful exercise than K1, notably for capabilities outdoors of blood coagulation. The completely different chemical constructions of nutritional vitamins K1 and K2 have an effect on their bioavailability and metabolism, with K2 having an extended half-life within the circulation system. A examine evaluating K1 and K2 in people discovered that the 2 have been equally absorbed, nevertheless, K2 (as menaquinone-7, MK-7) had greater bioavailability. Supplementation with K2 resulted in greater and extra secure circulating ranges of vitamin Okay in comparison with K1, and larger carboxylation of osteocalcin (a measure of noncoagulation vitamin Okay perform).2,8-10
Analysis on K2
Bone Well being
Conclusions are troublesome to attract from trials investigating vitamin K2 supplementation for fracture prevention. There are three causes for this: First, meta-analyses have mixed research of K1 and K2 supplementation. Second, a number of research from one analysis group have been retracted; and third, most trials haven’t documented K2 standing or K2 consumption at the beginning (if contributors have been already getting loads of vitamin Okay as K2, we might not count on to see any additional profit from taking extra K2).
- Postmenopausal girls consumed dairy merchandise enriched with calcium plus vitamin D3, and both no vitamin Okay or supplemental K1 or supplemental K2, for 12 months. All three teams improved complete BMD, and the 2 vitamin Okay teams additionally elevated lumbar backbone BMD.13
- In postmenopausal girls taking vitamin K2 or a placebo day by day for 3 years, decreases in age-related bone loss have been documented on the lumbar backbone and femoral neck, however not the full hip. Bone energy additionally elevated.14
- In postmenopausal girls, after one 12 months of K2 supplementation, BMD and bone thickness remained fixed, whereas within the placebo group, BMD and bone thickness decreased, suggesting that supplementation helped stop age-related bone loss.15
A vitamin Okay-dependent protein (matrix Gla protein, MGP) inhibits the calcification of sentimental tissues, together with the arterial partitions.16 Coronary artery calcification is a predictor of cardiovascular occasions like coronary heart assault and stroke.17 A number of observational research have discovered a diminished threat of coronary coronary heart illness or coronary calcification related to greater consumption of vitamin K2 particularly.18-23
Notably, in a few of these research, there was an affiliation between greater K2 consumption and decrease threat of arterial calcification or coronary coronary heart illness, however not for K1.20-22 It’s unclear why these completely different outcomes have been discovered for K1 and K2; it may very well be resulting from variations in bioavailability or organic exercise between the vitamin Okay varieties.2,24
Just like bone well being, trials on K2 supplementation measuring arterial calcification are troublesome to interpret as a result of most didn’t assess K2 standing or consumption previous to supplementation. Thus far, K2 supplementation trials haven’t reported reductions in calcification.25 The prevailing trials on K2 supplementation have been performed on most people (not vegetarians or vegans), who’re almost certainly already getting some K2 from animal merchandise.
Ought to Vegans (and Others With Low K2 Consumption) Complement With K2?
I like to recommend supplementing with a conservative quantity of K2 as a result of this vitamin isn’t current in most plant meals, and K2 could present some advantages that K1 doesn’t. Whether or not K2 supplementation of a plant-based food plan (which incorporates little to no K2) helps stop fractures or arterial calcification has not been straight studied but.
Though there is no such thing as a proof of toxicity related to vitamin K1 or K2 supplementation,26 and plenty of trials have used greater doses of K2, I like to recommend warning with the dose of K2 dietary supplements since vitamin Okay is a fat-soluble vitamin (fat-soluble nutritional vitamins usually accumulate extra within the physique than water-soluble nutritional vitamins). My multivitamin and mineral dietary supplements embody roughly one-third of the advisable day by day consumption for vitamin Okay as K2 (30 to 40 micrograms).
- Kidd PM. Nutritional vitamins D and Okay as pleiotropic vitamins: scientific significance to the skeletal and cardiovascular techniques and preliminary proof for synergy. Altern Med Rev 2010, 15:199-222.
- Beulens JW, Sales space SL, van den Heuvel EG, et al. The function of menaquinones (vitamin Okay(2)) in human well being. Br J Nutr 2013, 110:1357-1368.
- Apalset EM, Gjesdal CG, Eide GE, Inform GS. Consumption of vitamin K1 and K2 and threat of hip fractures: The Hordaland Well being Examine. Bone 2011, 49:990-995.
- Tsugawa N, Shiraki M, Suhara Y, et al. Low plasma phylloquinone focus is related to excessive incidence of vertebral fracture in Japanese girls. J Bone Miner Metab 2008, 26:79-85.
- Feskanich D, Weber P, Willett WC, et al. Vitamin Okay consumption and hip fractures in girls: a potential examine. Am J Clin Nutr 1999, 69:74-79.
- Hao G, Zhang B, Gu M, et al. Vitamin Okay consumption and the danger of fractures: A meta-analysis. Drugs (Baltimore) 2017, 96:e6725.
- Oregon State College. Linus Pauling Institute. Micronutrient Data Heart: Vitamin Okay [http://lpi.oregonstate.edu/infocenter/vitamins/vitaminK/]
- Schurgers LJ, Teunissen KJ, Hamulyak Okay, et al. Vitamin Okay-containing dietary dietary supplements: comparability of artificial vitamin K1 and natto-derived menaquinone-7. Blood 2007, 109:3279-3283.
- Akbulut AC, Pavlic A, Petsophonsakul P, et al. Vitamin K2 Wants an RDI Separate from Vitamin K1. Vitamins 2020, 12.
- Halder M, Petsophonsakul P, Akbulut AC, et al. Vitamin Okay: Double Bonds past Coagulation Insights into Variations between Vitamin K1 and K2 in Well being and Illness. Int J Mol Sci 2019, 20.
- Mott A, Bradley T, Wright Okay, et al. Correction to Impact of vitamin Okay on bone mineral density and fractures in adults: an up to date systematic assessment and meta-analysis of randomised managed trials. Osteoporos Int 2020, 31:2269-2270.
- Mott A, Bradley T, Wright Okay, et al. Impact of vitamin Okay on bone mineral density and fractures in adults: an up to date systematic assessment and meta-analysis of randomised managed trials. Osteoporos Int 2019, 30:1543-1559.
- Kanellakis S, Moschonis G, Tenta R, et al. Adjustments in parameters of bone metabolism in postmenopausal girls following a 12-month intervention interval utilizing dairy merchandise enriched with calcium, vitamin D, and phylloquinone (vitamin Okay(1)) or menaquinone-7 (vitamin Okay (2)): the Postmenopausal Well being Examine II. Calcif Tissue Int 2012, 90:251-262.
- Knapen MH, Drummen NE, Smit E, et al. Three-year low-dose menaquinone-7 supplementation helps lower bone loss in wholesome postmenopausal girls. Osteoporos Int 2013, 24:2499-2507.
- Ronn SH, Harslof T, Pedersen SB, Langdahl BL. Vitamin K2 (menaquinone-7) prevents age-related deterioration of trabecular bone microarchitecture on the tibia in postmenopausal girls. Eur J Endocrinol 2016, 175:541-549.
- Wen L, Chen J, Duan L, Li S. Vitamin Kdependent proteins concerned in bone and cardiovascular well being (Evaluation). Mol Med Rep 2018, 18:3-15.
- Greenland P, Bonow RO, Brundage BH, et al. ACCF/AHA 2007 scientific knowledgeable consensus doc on coronary artery calcium scoring by computed tomography in international cardiovascular threat evaluation and in analysis of sufferers with chest ache: a report of the American School of Cardiology Basis Scientific Knowledgeable Consensus Job Power (ACCF/AHA Writing Committee to Replace the 2000 Knowledgeable Consensus Doc on Electron Beam Computed Tomography) developed in collaboration with the Society of Atherosclerosis Imaging and Prevention and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol 2007, 49:378-402.
- Haugsgjerd TR, Egeland GM, Nygard OK, et al. Affiliation of dietary vitamin Okay and threat of coronary coronary heart illness in middle-age adults: the Hordaland Well being Examine Cohort. BMJ Open 2020, 10:e035953.
- Bellinge JW, Dalgaard F, Murray Okay, et al. Vitamin Okay Consumption and Atherosclerotic Cardiovascular Illness within the Danish Weight-reduction plan Most cancers and Well being Examine. J Am Coronary heart Assoc 2021:e020551.
- Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary consumption of menaquinone is related to a diminished threat of coronary coronary heart illness: the Rotterdam Examine. Journal of Vitamin 2004, 134:3100-3105.
- Beulens JW, Bots ML, Atsma F, et al. Excessive dietary menaquinone consumption is related to diminished coronary calcification. Atherosclerosis 2009, 203:489-493.
- Gast GC, de Roos NM, Sluijs I, et al. A excessive menaquinone consumption reduces the incidence of coronary coronary heart illness. Vitamin, metabolism, and cardiovascular ailments : NMCD 2009, 19:504-510.
- Maas AH, van der Schouw YT, Beijerinck D, et al. Vitamin Okay consumption and calcifications in breast arteries. Maturitas 2007, 56:273-279.
- Grober U, Reichrath J, Holick MF, Kisters Okay. Vitamin Okay: an previous vitamin in a brand new perspective. Dermatoendocrinol 2014, 6:e968490.
- Vlasschaert C, Goss CJ, Pilkey NG, et al. Vitamin Okay Supplementation for the Prevention of Cardiovascular Illness: The place Is the Proof? A Systematic Evaluation of Managed Trials. Vitamins 2020, 12.
- Institute of Drugs: Dietary Reference Intakes: The Important Information to Nutrient Necessities. 2006 [https://nap.nationalacademies.org/download/11537]