Our "No Return Necessary"
Money-Back Guarantee

If you don’t like something of ours, guess what happens next?

No, we don’t request you deliver it to a PO box in the Gobi Desert by carrier pigeon. Nor do we ask you to fill a cursed inkwell with orc’s blood and demon saliva and then use it to complete reams of return forms written in ancient Cyrillic script.

We just . . . wait for it . . . give you your money back. Holy moo cows. And that means you can say "yes" now and decide later.

Will Vitamin D+K maximize energy and immunity and banish fatigue and anxiety? No.

Will it give you glowing skin, hair, and nails overnight? Absolutely not.

But can Vitamin D+K support your bone health, muscle function and performance, and immune health? Yes. Or your money back.

And how can Vitamin D+K do these things?

Vitamins D3, K1, and K2 are critical nutrients involved in the production of numerous enzymes and hormones in the body that regulate critical processes like calcium metabolism, blood clotting, bone and cardiovascular health, immune health, insulin sensitivity, and more.

Despite their importance, however, research shows that as many as 20% of people aren’t getting enough vitamin D3 for optimal health and performance and 48% of people aren’t getting enough vitamin K1 and K2, including those with a healthy diet and lifestyle.[8][9][10][11]

These “subclinical deficiencies” are serious, too—they’re associated with numerous health problems, including mood disruption, muscle weakness, impaired bone and heart health, and more.[12][13][14][15][16][17]

What’s more, while it’s possible to get enough vitamin D and K to maintain health through diet alone, this can be difficult because:

  1. The best natural source of vitamin D3 is exposure to sunlight, and many people don’t consistently spend enough time in the sun to produce enough vitamin D3, especially those who use sunscreen or have darker skin pigmentation.[18][19][20]
  2. There aren’t many practical dietary sources of vitamin K1 and K2, with the best choices being dark leafy greens, cheese, butter, seaweed, fermented foods, and pork and chicken—foods that many people don’t eat enough of to meet their body’s K1 and K2 needs.
  3. There are several factors that can interfere with the body’s absorption and utilization of vitamins D3, K1, and K2, including gut health, age, body composition, and genetics.[21][22][23][24]

Additionally, research suggests that the recommended daily allowance (RDA) for vitamins D3, K1, and K2 is adequate for preventing deficiencies, but they may not produce optimal health and longevity, which should be the ultimate goal.

Thus, many health-conscious people who eat a nutritious diet also choose to supplement with vitamins D3, K1, and K2, especially if they’re physically active (because this may increase the body’s needs for these vitamins).[25]

So order now, try Vitamin D+K risk-free, and see for yourself why we believe it’s the perfect vitamin D3, K1, and K2 supplement.

Will Vitamin D+K maximize energy and immunity and banish fatigue and anxiety? No.

Will it give you glowing skin, hair, and nails overnight? Absolutely not.

But can Vitamin D+K support your bone health, muscle function and performance, and immune health?

Yes. Or your money back.

And how can Vitamin D+K do these things?

Vitamins D3, K1, and K2 are critical nutrients involved in the production of numerous enzymes and hormones in the body that regulate critical processes like calcium metabolism, blood clotting, bone and cardiovascular health, immune health, insulin sensitivity, and more.

Despite their importance, however, research shows that as many as 20% of people aren’t getting enough vitamin D3 for optimal health and performance and 48% of people aren’t getting enough vitamin K1 and K2, including those with a healthy diet and lifestyle.[1][2][3][4]

These “subclinical deficiencies” are serious, too—they’re associated with numerous health problems, including mood disruption, muscle weakness, impaired bone and heart health, and more.[5][6][7][8][9][10]

What’s more, while it’s possible to get enough vitamin D and K to maintain health through diet alone, this can be difficult because:

  1. The best natural source of vitamin D3 is exposure to sunlight, and many people don’t consistently spend enough time in the sun to produce enough vitamin D3, especially those who use sunscreen or have darker skin pigmentation.[11][12][13]
  2. There aren’t many practical dietary sources of vitamin K1 and K2, with the best choices being dark leafy greens, cheese, butter, seaweed, fermented foods, and pork and chicken—foods that many people don’t eat enough of to meet their body’s K1 and K2 needs.
  3. There are several factors that can interfere with the body’s absorption and utilization of vitamins D3, K1, and K2, including gut health, age, body composition, and genetics.[14][15][16][17]

Additionally, research suggests that the recommended daily allowance (RDA) for vitamins D3, K1, and K2 is adequate for preventing deficiencies, but they may not produce optimal health and longevity, which should be the ultimate goal.

Thus, many health-conscious people who eat a nutritious diet also choose to supplement with vitamins D3, K1, and K2, especially if they’re physically active (because this may increase the body’s needs for these vitamins).[18]

  • 25 peer-reviewed scientific studies support Vitamin D+K’s doses of vitamins D3, K1, and K2[19] That’s 375 pages of scientific research that shows Vitamin D+K works the way we say it does.
  • Contains no artificial fillers, food dyes, or other chemical junk[20] While these types of chemicals may not be as dangerous as some people claim, studies suggest that regular consumption of them may indeed be harmful to our health. And that’s why you won’t find them in Vitamin D+K.
  • Analyzed for purity and potency in a state-of-the-art ISO 17025 accredited lab[21] Every bottle of Vitamin D+K is guaranteed to provide exactly what the label claims and nothing else—no heavy metals, microbes, allergens, or other contaminants.
  • Total formulation transparency (no proprietary blends)[22] This means you know exactly what’s in every serving of Vitamin D+K—every dose of every ingredient—and can verify the accuracy and efficacy of the formulation.
  • Made in the USA with globally sourced ingredients in NSF-certified and FDA-inspected and cGMP-compliant facilities

Vitamin D+K is also backed by our “No Return Necessary” money-back guarantee that works like this:

If you don’t absolutely love Vitamin D+K, just let us know, and we’ll give you a full refund on the spot. No forms or return necessary.

So order now, try Vitamin D+K risk-free, and see for yourself why we believe it’s the perfect vitamin D3, K1, and K2 supplement.

Notice to California Consumers

WARNING: Consuming this product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov/food.

Ingredients (330 micrograms per serving)

Vitamin D3 (50 micrograms/2,000 IU per serving)

Vitamin D3 (cholecalciferol) is a substance that plays a critical role in the synthesis of many hormones and enzymes that support physical and mental health, performance, and well-being, including testosterone, estrogen, calcitriol, and others.

Research shows that supplementation with vitamin D3 . . .

  • Supports bone health and strength[23][24]
  • Supports immune health and reduces the risk of respiratory infections[25]
  • Supports muscle function and performance[26][27][28][29]
  • Supports calcium absorption[30][31]
  • Supports insulin secretion and reduces the risk of insulin resistance[32][33]

The recommended daily allowance (RDA) for vitamin D3 for adults is between 15 and 20 mcg (600 and 800 IU), but research shows that this often isn’t enough to prevent deficiencies or insufficiencies, even in people who eat a healthy diet.[34]

On the contrary, studies show that 50 mcg (2,000 IU) per day is required to safely prevent vitamin D3 deficiencies and insufficiencies in nearly everyone.[35]

Vitamin D+K contains 50 mcg (2,000 IU) of vitamin D3.

Vitamins K1 and K2 (280 micrograms per serving)

Vitamins K1 and K2 are substances required for hundreds of key bodily processes, including bone metabolism, blood clotting, blood vessel health, and more.

For example, vitamins K1 and K2 are needed to activate and utilize a protein called osteocalcin, which helps maintain healthy bones, and another called prothrombin, which improves blood clotting and wound healing.[36][37]

Vitamins K1 and K2 also activate a group of proteins in the body called Matrix Gla, which reduce calcium buildup in blood vessels and thereby can support circulation and heart health.[38]

Despite the vital importance of these vitamins, however, it can be difficult to get enough to maintain health through diet alone because . . .

  1. Foods high in vitamin K1 tend to be low in vitamin K2 and vice versa.
  2. Plant sources of both vitamins are often poorly absorbed.[39]

Thus, many health-conscious people who eat a nutritious diet also choose to supplement with vitamins K1 and K2, and with the MK-7 form of vitamin K2 in particular (rather than MK-4 or MK-9) because it’s the most scientifically validated form for enhancing vitamin K2 status.[40][41][42]

Research shows that supplementation with vitamins K1 and K2 . . .

The recommended daily allowance (RDA) for vitamin K is 120 mcg per day for men and women (and currently, it doesn’t specify how this should break down into K1 and K2), but studies show that this amount is likely suboptimal for maximizing health and performance.[55][56][57][58]

For example, research showing improvements in bone mineral density and cardiovascular health from vitamin K2 supplementation has typically used doses of 180 mcg per day.[59] What’s more, other studies have found that consuming 300-to-500 mcg of vitamin K1 per day was associated with improved cognitive health and insulin sensitivity.[60]

Vitamin D+K contains 280 mcg of vitamin K, with 100 mcg of vitamin K1 (as phytonadione) and 180 mcg of vitamin K2 (as MK-7).

No Artificial Food Dyes or Other Chemical Junk

Artificial food dyes aren’t a hazard per se, but studies show they can cause negative effects in some people, including gastrointestinal toxicity and behavioral disorders.[61][62][63][64][65]

No Artificial Food Dyes or Other Chemical Junk

Lab Tested for Potency & Purity

Every bottle of Vitamin D+K is analyzed in a state-of-the-art ISO 17025 accredited lab to verify what is and isn’t in it. That way, you know exactly what you’re getting and putting into your body.

Lab Tested for Potency & Purity

The #1 brand of all-natural sports supplements.

Over 4,000,000 bottles sold to over 800,000 customers who have left us over 45,000 5-star reviews.

Natural Ingredients
No Chemical Junk

Vitamin D+K doesn’t just “contain natural ingredients”—every ingredient is naturally sourced. We don’t use artificial or synthetic substances of any kind.

Science-Backed Ingredients
Science-Backed Ingredients

Every ingredient in Vitamin D+K is backed by peer-reviewed scientific research demonstrating clear benefits in healthy humans.

Clinically Effective Doses
Clinically Effective Ingredients & Doses

Every ingredient in Vitamin D+K is included at clinically effective levels, which are the exact amounts shown to be safe and effective in peer-reviewed scientific research.

Lab Tested
Lab Tested

Vitamin D+K is tested by third-party labs for heavy metals, microbes, allergens, and other contaminants to ensure it meets FDA purity standards.

Made in USA
Made in USA with Globally Sourced Ingredients

Vitamin D+K is proudly made in America in NSF-certified and FDA-inspected facilities in accordance with the Current Good Manufacturing Practice (cGMP) regulations.

100% Money-Back-Guarantee
"No Return Necessary"
Money-Back Guarantee

If you don't absolutely love Vitamin D+K, you get a prompt and courteous refund. No forms or returns necessary.

Trusted by scientists, doctors, and everyday fitness folk alike.

Previous
  • Dr. Spencer Nadolsky, MD

    Board-Certified Family Medicine Physician, a Diplomate of the American Board of Obesity Medicine, and Legion Advisory Board Member

    "There are a lot of sleazy supplement companies out there, but Legion is not one of them. Their products are free of fillers and inactive ingredients and they take the time (and money) to test them with independent labs to ensure you're getting what you pay for."

  • Menno Henselmans, MS

    Founder of Bayesian Bodybuilding, Published Scientist, Physique Coach, and Legion Advisory Board Member

    "Legion consults with nutrition experts to make honest, science-based products and then proves they're genuine with independent lab work. That's how all supplement companies should operate."

  • Dr. Bill Campbell, PhD

    Professor of Exercise Science at University of South Florida and Legion Advisory Board Member

    "Legion is science-based at its core. All of their products contain doses proven to be effective by scientific studies, and they fund new research. They don't just want to sell you supplements—they want to change the supplement industry for the better."

  • James Krieger, MS

    Published Scientist, Author, and Speaker

    "There are three reasons I like Legion. First, they use ingredients backed by independent, peer-reviewed scientific studies. Second, the quality of their supplements exceeds many in the industry and you know you’re getting what’s on the label. Third, Mike Matthews is a solid evidence-based guy who doesn’t over-hype."

  • Chris Barakat, MS

    Published Scientist and Physique Coach

    "I've been involved in the supplement industry for over a decade now, and I can tell you that Legion is the ONLY company doing EVERYTHING right! They make effective products that are backed by scientific evidence, properly dose all of their ingredients, source every ingredient from the highest-quality sources, and are transparent about exactly what goes in each and every product."

  • Kurtis Frank

    Co-Founder and Former Lead Researcher & Writer of Examine.com

    "With Legion, you really do get what you pay for. Each and every product is packed with effective doses of effective ingredients, and what’s on the label is what's actually in the bottle."

  • Jordan Syatt

    Strength and Nutrition Coach

    "Legion is a tremendous company run by people I trust and respect. The quality of their supplements is second to no one. And while I don’t use many supplements, the only ones I do come from Legion."

  • Sal Di Stefano, Justin Andrews, and Adam Schafer

    Hosts of The Mind Pump Podcast

    "When it comes to quality and integrity, Legion is among the best. Their products only include ingredients that are backed by research and in doses that are proven to be effective in scientific studies."

Next
Vitamin D+K Lab Test

Frequently Asked Questions

How do I use Vitamin D+K?
What makes Vitamin D+K different from other vitamin D or vitamin K supplements on the market?
Can I take Vitamin D+K with other Legion supplements?
A supplement I take already contains vitamin D and K. Can I benefit from Vitamin D+K?
How much vitamin D and K should I take per day? How much is too much?
What type of effects should I notice?
What does the Prop65 warning on the labels mean?
Can Vitamin D+K be taken while pregnant or breastfeeding?
Can Vitamin D+K be taken with medication?
Is Vitamin D+K gluten-free? Soy-free? Dairy-free?
Is Vitamin D+K vegetarian or vegan friendly?

+References

4. What We Eat in America: Usual Nutrient Intake from Food, Beverages, and Dietary Supplements.

United States Department of Agriculture. Accessed May 10, 2023.

5. What We Eat in America: Usual Nutrient Intake from Food and Beverages.

United States Department of Agriculture. Accessed May 10, 2023.

6. Office of Dietary Supplements - Vitamin K.

National Institutes of Health Office of Dietary Supplements

7. Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?.

Ames BN, Grant WB, Willett WC. Nutrients. 2021;13(2):499. Published 2021 Feb 3. doi:10.3390/nu13020499.

8. Vitamin D insufficiency.

Thacher TD, Clarke BL. Mayo Clin Proc. 2011;86(1):50-60. doi:10.4065/mcp.2010.0567.

9. Vitamin D Deficiency, Osteoporosis and Effect on Autoimmune Diseases and Hematopoiesis: A Review.

De Martinis M, Allegra A, Sirufo MM, et al. Int J Mol Sci. 2021;22(16):8855. Published 2021 Aug 17. doi:10.3390/ijms22168855.

10. Vitamin d deficiency in postmenopausal women - biological correlates.

Capatina C, Carsote M, Caragheorgheopol A, Poiana C, Berteanu M. Maedica (Bucur). 2014;9(4):316-322.

11. Subclinical vitamin D deficiency in postmenopausal women with low vertebral bone mass.

Villareal DT, Civitelli R, Chines A, Avioli LV. J Clin Endocrinol Metab. 1991 Mar;72(3):628-34. doi: 10.1210/jcem-72-3-628. PMID: 1997517.

12. Vitamin D deficiency and depression in adults: systematic review and meta-analysis.

Anglin RE, Samaan Z, Walter SD, McDonald SD. Br J Psychiatry. 2013 Feb;202:100-7. doi: 10.1192/bjp.bp.111.106666. PMID: 23377209.

13. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study.

Geleijnse JM, Vermeer C, Grobbee DE, et al. J Nutr. 2004;134(11):3100-3105. doi:10.1093/jn/134.11.3100.

14. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis.

Holick MF. Am J Clin Nutr. 2004;79(3):362-371. doi:10.1093/ajcn/79.3.362 [published correction appears in Am J Clin Nutr. 2004 May;79(5):890].

15. The effect of sunscreen on vitamin D: a review.

Neale RE, Khan SR, Lucas RM, Waterhouse M, Whiteman DC, Olsen CM. Br J Dermatol. 2019;181(5):907-915. doi:10.1111/bjd.17980.

16. Colour Counts: Sunlight and Skin Type as Drivers of Vitamin D Deficiency at UK Latitudes.

Webb AR, Kazantzidis A, Kift RC, Farrar MD, Wilkinson J, Rhodes LE. Nutrients. 2018;10(4):457. Published 2018 Apr 7. doi:10.3390/nu10040457.

17. The Relationship Among Intestinal Bacteria, Vitamin K and Response of Vitamin K Antagonist: A Review of Evidence and Potential Mechanism.

Yan H, Chen Y, Zhu H, et al. Front Med (Lausanne). 2022;9:829304. Published 2022 Apr 18. doi:10.3389/fmed.2022.829304.

18. Vitamin D status and body composition: a cross-sectional study among employees at a private university in Lebanon.

Al Hayek S, Matar Bou Mosleh J, Ghadieh R, El Hayek Fares J. BMC Nutr. 2018;4:31. Published 2018 Jul 26. doi:10.1186/s40795-018-0239-6.

19. Vitamin K status and physical decline in older adults—The Longitudinal Aging Study Amsterdam.

van Ballegooijen AJ, van Putten SR, Visser M, Beulens JW, Hoogendijk EO. Maturitas. 2018;113:73-79. doi:10.1016/J.MATURITAS.2018.04.013.

20. Vitamin D and aging.

Gallagher JC. Endocrinol Metab Clin North Am. 2013;42(2):319-332. doi:10.1016/j.ecl.2013.02.004.

21. The Effect of Exercise and Heat on Vitamin Requirements.

Research I of M (US) C on MN, Marriott BM. 1993. Accessed May 17, 2023.

8. What We Eat in America: Usual Nutrient Intake from Food, Beverages, and Dietary Supplements.

United States Department of Agriculture. Accessed May 10, 2023.

9. What We Eat in America: Usual Nutrient Intake from Food and Beverages.

United States Department of Agriculture. Accessed May 10, 2023.

10. Office of Dietary Supplements - Vitamin K.

National Institutes of Health Office of Dietary Supplements

11. Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?.

Ames BN, Grant WB, Willett WC. Nutrients. 2021;13(2):499. Published 2021 Feb 3. doi:10.3390/nu13020499.

12. Vitamin D insufficiency.

Thacher TD, Clarke BL. Mayo Clin Proc. 2011;86(1):50-60. doi:10.4065/mcp.2010.0567.

13. Vitamin D Deficiency, Osteoporosis and Effect on Autoimmune Diseases and Hematopoiesis: A Review.

De Martinis M, Allegra A, Sirufo MM, et al. Int J Mol Sci. 2021;22(16):8855. Published 2021 Aug 17. doi:10.3390/ijms22168855.

14. Vitamin d deficiency in postmenopausal women - biological correlates.

Capatina C, Carsote M, Caragheorgheopol A, Poiana C, Berteanu M. Maedica (Bucur). 2014;9(4):316-322.

15. Subclinical vitamin D deficiency in postmenopausal women with low vertebral bone mass.

Villareal DT, Civitelli R, Chines A, Avioli LV. J Clin Endocrinol Metab. 1991 Mar;72(3):628-34. doi: 10.1210/jcem-72-3-628. PMID: 1997517.

16. Vitamin D deficiency and depression in adults: systematic review and meta-analysis.

Anglin RE, Samaan Z, Walter SD, McDonald SD. Br J Psychiatry. 2013 Feb;202:100-7. doi: 10.1192/bjp.bp.111.106666. PMID: 23377209.

17. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study.

Geleijnse JM, Vermeer C, Grobbee DE, et al. J Nutr. 2004;134(11):3100-3105. doi:10.1093/jn/134.11.3100.

19. The effect of sunscreen on vitamin D: a review.

Neale RE, Khan SR, Lucas RM, Waterhouse M, Whiteman DC, Olsen CM. Br J Dermatol. 2019;181(5):907-915. doi:10.1111/bjd.17980.

20. Colour Counts: Sunlight and Skin Type as Drivers of Vitamin D Deficiency at UK Latitudes.

Webb AR, Kazantzidis A, Kift RC, Farrar MD, Wilkinson J, Rhodes LE. Nutrients. 2018;10(4):457. Published 2018 Apr 7. doi:10.3390/nu10040457.

21. The Relationship Among Intestinal Bacteria, Vitamin K and Response of Vitamin K Antagonist: A Review of Evidence and Potential Mechanism.

Yan H, Chen Y, Zhu H, et al. Front Med (Lausanne). 2022;9:829304. Published 2022 Apr 18. doi:10.3389/fmed.2022.829304.

22. Vitamin D status and body composition: a cross-sectional study among employees at a private university in Lebanon.

Al Hayek S, Matar Bou Mosleh J, Ghadieh R, El Hayek Fares J. BMC Nutr. 2018;4:31. Published 2018 Jul 26. doi:10.1186/s40795-018-0239-6.

23. Vitamin K status and physical decline in older adults—The Longitudinal Aging Study Amsterdam.

van Ballegooijen AJ, van Putten SR, Visser M, Beulens JW, Hoogendijk EO. Maturitas. 2018;113:73-79. doi:10.1016/J.MATURITAS.2018.04.013.

24. Vitamin D and aging.

Gallagher JC. Endocrinol Metab Clin North Am. 2013;42(2):319-332. doi:10.1016/j.ecl.2013.02.004.

25. The Effect of Exercise and Heat on Vitamin Requirements.

Research I of M (US) C on MN, Marriott BM. 1993. Accessed May 17, 2023.

26. Office of Dietary Supplements - Vitamin D.

National Institutes of Health Office of Dietary Supplements. Accessed May 10, 2023.

27. Vitamin D and calcium: a systematic review of health outcomes.

Chung M, Balk EM, Brendel M, et al. Evid Rep Technol Assess (Full Rep). Aug 2009;(183):1-420.

28. Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis.

Martineau AR, Jolliffe DA, Greenberg L, et al. Health Technol Assess. Jan 2019;23(2):1-44. doi:10.3310/hta23020

29. Office of Dietary Supplements - Vitamin D.

National Institutes of Health Office of Dietary Supplements. Accessed May 10, 2023.

30. Effects of vitamin D3 supplementation for 12 weeks on serum levels of anabolic hormones, anaerobic power, and aerobic performance in active male subjects: A randomized, double-blind, placebo-controlled trial.

Ramezani Ahmadi A, Mohammadshahi M, Alizadeh A, Ahmadi Angali K, Jahanshahi A. Eur J Sport Sci. Nov 2020;20(10):1355-1367. doi:10.1080/17461391.2020.1713218

31. Influence of Sunlight and Oral D3 Supplementation on Serum 25(OH)D Concentration and Exercise Performance in Elite Soccer Players.

Michalczyk MM, Gołaś A, Maszczyk A, Kaczka P, Zając A. Nutrients. 2020;12(5):1311. Published 2020 May 4. doi:10.3390/nu12051311.

32. ISSN exercise & sports nutrition review update: research & recommendations.

Kerksick CM, Wilborn CD, Roberts MD, et al. J Int Soc Sports Nutr. Aug 1 2018;15(1):38. doi:10.1186/s12970-018-0242-y

33. Office of Dietary Supplements - Vitamin D.

National Institutes of Health Office of Dietary Supplements. Accessed May 10, 2023.

34. Mechanism of action of 1,25-dihydroxyvitamin D3 on intestinal calcium absorption.

Christakos S. Rev Endocr Metab Disord. 2012;13(1):39-44. doi:10.1007/s11154-011-9197-x.

35. The effect of vitamin D3 on insulin secretion and peripheral insulin sensitivity in type 2 diabetic patients.

Borissova AM, Tankova T, Kirilov G, Dakovska L, Kovacheva R. Int J Clin Pract. May 2003;57(4):258-61.

37. Office of Dietary Supplements - Vitamin D.

National Institutes of Health Office of Dietary Supplements. Accessed May 10, 2023.

39. Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trials.

Inaba N, Sato T, Yamashita T. J Nutr Sci Vitaminol (Tokyo). 2015;61(6):471-480. doi:10.3177/jnsv.61.471.

40. Chemistry, nutritional sources, tissue distribution and metabolism of vitamin K with special reference to bone health.

Shearer MJ, Bach A, Kohlmeier M. J Nutr. 1996;126(4 Suppl):1181S-6S. doi:10.1093/jn/126.suppl_4.1181S.

41. Extracellular matrix mineralization is regulated locally; different roles of two gla-containing proteins.

Murshed M, Schinke T, McKee MD, Karsenty G. J Cell Biol. 2004;165(5):625-630. doi:10.1083/jcb.200402046.

42. Office of Dietary Supplements - Vitamin K.

National Institutes of Health Office of Dietary Supplements. Accessed May 10, 2023.

43. MK-7 and Its Effects on Bone Quality and Strength.

Sato T, Inaba N, Yamashita T. Nutrients. 2020;12(4):965. Published 2020 Mar 31. doi:10.3390/nu12040965.

44. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women.

Sato T, Schurgers LJ, Uenishi K. Nutr J. 2012;11:93. Published 2012 Nov 12. doi:10.1186/1475-2891-11-93.

45. Molecular Pathways and Roles for Vitamin K2-7 as a Health-Beneficial Nutraceutical: Challenges and Opportunities.

Jadhav N, Ajgaonkar S, Saha P, et al. Front Pharmacol. 2022;13:896920. Published 2022 Jun 14. doi:10.3389/fphar.2022.896920.

46. Office of Dietary Supplements - Vitamin K.

National Institutes of Health Office of Dietary Supplements. Accessed April 2023.

47. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women.

Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E. Osteoporos Int. Sep 2013;24(9):2499-507. doi:10.1007/s00198-013-2325-6.

48. Dietary vitamin K2 supplement improves bone status after lung and heart transplantation.

Forli L, Bollerslev J, Simonsen S, et al. Transplantation. Feb 27 2010;89(4):458-64. doi:10.1097/TP.0b013e3181c46b69.

49. Menaquinone-7 Supplementation Improves Osteogenesis in Pluripotent Stem Cell Derived Mesenchymal Stem Cells.

Akbulut AC, Wasilewski GB, Rapp N, et al. Front Cell Dev Biol. 2020;8:618760. doi:10.3389/fcell.2020.618760.

50. MK-7 and Its Effects on Bone Quality and Strength.

Sato T, Inaba N, Yamashita T. Nutrients. Mar 31 2020;12(4)doi:10.3390/nu12040965.

51. Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trials.

Inaba N, Sato T, Yamashita T. J Nutr Sci Vitaminol (Tokyo). 2015;61(6):471-80. doi:10.3177/jnsv.61.471.

52. Vitamin D and Calcium for the Prevention of Fracture: A Systematic Review and Meta-analysis.

Yao P, Bennett D, Mafham M, et al. JAMA Network Open. 2019;2(12):e1917789-e1917789. doi:10.1001/jamanetworkopen.2019.17789.

54. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study.

Geleijnse JM, Vermeer C, Grobbee DE, et al. J Nutr. Nov 2004;134(11):3100-5. doi:10.1093/jn/134.11.3100.

55. High dietary menaquinone intake is associated with reduced coronary calcification.

Beulens JW, Bots ML, Atsma F, et al. Atherosclerosis. Apr 2009;203(2):489-93. doi:10.1016/j.atherosclerosis.2008.07.010.

56. Vitamin K supplementation and progression of coronary artery calcium in older men and women.

Shea MK, O'Donnell CJ, Hoffmann U, et al. Am J Clin Nutr. Jun 2009;89(6):1799-807. doi:10.3945/ajcn.2008.27338.

57. Office of Dietary Supplements - Vitamin K.

National Institutes of Health Office of Dietary Supplements. Accessed April 2023.

58. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women.

Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E. Osteoporos Int. Sep 2013;24(9):2499-507. doi:10.1007/s00198-013-2325-6.

59. Dietary vitamin K2 supplement improves bone status after lung and heart transplantation.

Forli L, Bollerslev J, Simonsen S, et al. Transplantation. Feb 27 2010;89(4):458-64. doi:10.1097/TP.0b013e3181c46b69.

60. Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trials.

Inaba N, Sato T, Yamashita T. J Nutr Sci Vitaminol (Tokyo). 2015;61(6):471-80. doi:10.3177/jnsv.61.471.

61. Toxicological significance of azo dye metabolism by human intestinal microbiota.

Feng J, Cerniglia CE, Chen H. Division of Microbiology, National Center for Toxicological Research, US Food and Drug Administration, AR , USA. Front Biosci (Elite Ed). 2012 Jan 1;4:568-86.

62. Artificial food dyes and attention deficit hyperactivity disorder.

Kanarek RB. Department of Psychology, Tufts University, Medford, Massachusetts, USA. Nutr Rev. 2011 Jul;69(7):385-91.

63. Meta-analysis of attention-deficit/hyperactivity disorder or attention-deficit/hyperactivity disorder symptoms, restriction diet, and synthetic food color additives.

Nigg JT, Lewis K, Edinger T, Falk M. Oregon Health and Science University, Portland, OR, USA. J Am Acad Child Adolesc Psychiatry. 2012 Jan;51(1):86-97.e8.

64. Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial.

McCann D, Barrett A, Cooper A, Crumpler D, Dalen L, Grimshaw K, Kitchin E, Lok K, Porteous L, Prince E, Sonuga-Barke E, Warner JO, Stevenson J. School of Psychology, Department of Child Health, University of Southampton, Southampton, UK. Lancet. 2007 Nov 3;370(9598):1560-7.

65. Effect of food azo dye tartrazine on learning and memory functions in mice and rats, and the possible mechanisms involved.

Gao Y, Li C, Shen J, Yin H, An X, Jin H. Scientific and Technological College of Chemistry and Biology, Yantai Univ., Yantai, PR China. J Food Sci. 2011 Aug;76(6):T125-9.