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At Healthfully, we strive to deliver objective content that is accurate and up-to-date. Our team periodically reviews articles in order to ensure content quality. The sources cited below consist of evidence from peer-reviewed journals, prominent medical organizations, academic associations, and government data.
The information contained on this site is for informational purposes only, and should not be used as a substitute for the advice of a professional health care provider. Please check with the appropriate physician regarding health questions and concerns. Although we strive to deliver accurate and up-to-date information, no guarantee to that effect is made.
Vitamin K2 Toxicity
Vitamin K consists of two fat-soluble vitamins, vitamin K-1 and K-2, that have similar structures and functions 3. Vitamin K-2, or menaquinone, can be synthesized in your body from vitamin K-1 and used for several biochemical reactions, such as maintaining bone strength and promoting blood coagulation, or clotting 3. There is no known toxicity for either form of vitamin K, but some side effects may still be associated with its supplementation 3. Consult your physician before using a supplement containing vitamin K-2 3.
Allergic Reaction
Although rare, some individuals may experience an allergic reaction to menaquinone. An allergic reaction to vitamin K-2 occurs when your body incorrectly identifies it as a foreign toxin and responds by increasing histamine levels in your blood stream 3. A vitamin K-2 allergy is considered a medical emergency -- seek medical attention immediately if you suspect an allergic reaction 3.
Blood Pressure and Clotting
Allergy to Vitamin B-12
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Vitamin K may increase blood plasma volume, which increases the thickness of your blood 3. If you suffer from high blood pressure or have naturally high blood plasma volume levels, vitamin K-2 supplementation may increase your risk of developing hypertension and cardiovascular disease due to an over-thickening of your blood 3. Consult your physician in regard to how much vitamin K is acceptable to take if you are on any medications for high blood pressure or blood-thinning medications 3.
Gastrointestinal Distress
The most common side effects of vitamin K-2 supplementation involve gastrointestinal distress due to an inability of your digestive system to properly metabolize vitamin K supplements 3. The risk of developing gastrointestinal distress with vitamin K supplements decreases when the supplement is taken within the recommended guidelines 3. Taking vitamin K with adequate amounts of water may also reduce the risk of digestive side effects 3.
Drug Interactions
Zoloft & Vitamin B12 Absorption
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According to the University of Maryland Medical Center, vitamin K supplements may have adverse interactions with some drugs and medications 3. Certain antibiotics may interfere with the absorption of vitamin K, which may cause a vitamin K deficiency 3. Warfarin, a blood-thinning medication, may be affected by vitamin K supplementation 3. Vitamin K supplements may also interfere with some weight loss and cholesterol-lowering drugs, such as Orlistat, Olestra and bile acid sequestrants 3.
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References
- "Nutrition for Health, Fitness, and Sport"; Melvin H. Williams; 2002
- "Linus Pauling Institute"; Vitamin K; Jane Higdon; 2004
- UMMC; Vitamin K; 2009
- Holick MF, Gordon CM. Patient Guide to Vitamin D Deficiency. The Journal of Clinical Endocrinology & Metabolism. 2011;96(7):1-2. doi:10.1210/jcem.96.7.zeg33a
- Sunyecz JA. The use of calcium and vitamin D in the management of osteoporosis. Ther Clin Risk Manag. 2008;4(4):827-836. doi:10.2147/tcrm.s3552
- Giovannucci E, Liu Y, Hollis BW, Rimm EB. 25-hydroxyvitamin D and risk of myocardial infarction in men: a prospective study. Arch Intern Med. 2008;168(11):1174-1180. doi:10.1001/archinte.168.11.1174
- Gorham ED, Garland CF, Garland FC, et al. Optimal vitamin D status for colorectal cancer prevention: a quantitative meta analysis. Am J Prev Med. 2007;32(3):210-216. doi:10.1016/j.amepre.2006.11.004
- Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. The American Journal of Clinical Nutrition. 2007;85(6):1586-1591. doi:10.1093/ajcn/85.6.1586
- Prentice RL, Pettinger MB, Jackson RD, et al. Health risks and benefits from calcium and vitamin D supplementation: Women’s Health Initiative clinical trial and cohort study. Osteoporos Int. 2013;24(2):567-580. doi:10.1007/s00198-012-2224-2
- Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr. 2010;91(5):1255-1260. doi:10.3945/ajcn.2009.29094
- Salehpour A, Hosseinpanah F, Shidfar F, et al. A 12-week double-blind randomized clinical trial of vitamin D₃ supplementation on body fat mass in healthy overweight and obese women. Nutr J. 2012;11:78. doi:10.1186/1475-2891-11-78
- Carrillo AE, Flynn MG, Pinkston C, et al. Impact of vitamin D supplementation during a resistance training intervention on body composition, muscle function, and glucose tolerance in overweight and obese adults. Clin Nutr. 2013;32(3):375-381. doi:10.1016/j.clnu.2012.08.014
- Marcinowska-Suchowierska E, Kupisz-Urbańska M, Łukaszkiewicz J, Płudowski P, Jones G. Vitamin D Toxicity-A Clinical Perspective. Front Endocrinol. 2018;9:550. doi:10.3389/fendo.2018.00550
- Ross AC, Manson JE, Abrams SA, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011;96(1):53-58. doi:10.1210/jc.2010-2704
- Bouillon R, Van Schoor NM, Gielen E, et al. Optimal vitamin D status: a critical analysis on the basis of evidence-based medicine. J Clin Endocrinol Metab. 2013;98(8):E1283-E1304. doi:10.1210/jc.2013-1195
- American Academy of Dermatology. Position Statement of Vitamin D. 2010.
- Taksler GB, Cutler DM, Giovannucci E, Keating NL. Vitamin D deficiency in minority populations. Public Health Nutr. 2015;18(3):379-391. doi:10.1017/S1368980014000457
- Holick MF, Binkley NC, Bischoff-Ferrari HA, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(7):1911-1930. doi:10.1210/jc.2011-0385
- Cannell JJ, Vieth R, Umhau JC, et al. Epidemic Influenza and Vitamin D. Epidemiol Infect. 2006; 134:1129-40.
- Carrillo AE1, Flynn MG, Pinkston C, Markofski MM, Jiang Y, Donkin SS, Teegarden D. Impact of Vitamin D Supplementation During a Resistance Training Intervention on Body Composition, Muscle Function, and Glucose Tolerance in Overweight and Obese Adults. Clin Nutr. 2013 Jun;32(3):375-81. doi: 10.1016/j.clnu.2012.08.014. Epub 2012 Aug 31.
- Ginde AA, Mansbach JM, Camargo CA, Jr. Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2009; 169:384-90.
- Giovannucci E, Liu Y, Hollis BW, Rimm EB. 25-hydroxyvitamin D and Risk of Myocardial Infarction in Men: a Prospective Study. Arch Intern Med. 2008; 168:1174-80.
- Gorham ED, Garland CF, Garland FC, Grant WB, Mohr SB, Lipkin M, Newmark HL, Giovannucci E, Wei M, Holick MF. Optimal Vitamin D Status for Colorectal Cancer Prevention: a Quantitative Meta-analysis. Am J Prev Med. 2007 Mar;32(3):210-6.
- Heaney, Robert P. “The Vitamin D Requirement in Health and Disease.” The Journal of Steroid Biochemistry & Molecular Biology 97 (2005):13-9.
- Holick MF. Vitamin D. In: Shils M, Olson J, Shike M, Ross AC, ed. Modern Nutrition in Health and Disease, 9th ed. Baltimore: Williams and Wilkins, 1999.
- National Institutes of Health Office of Dietary Supplements. Vitamin D: Dietary Supplement Fact Sheet. University of Ottawa Evidence-based Practice Center. Effectiveness and Safety of Vitamin D in Relation to Bone Health. Agency for Healthcare Research and Quality. Aug 2007: 07-E013.
- Salehpour A1, Hosseinpanah F, Shidfar F, Vafa M, Razaghi M, Dehghani S, Hoshiarrad A, Gohari M. A 12-week Double-blind Randomized Clinical Trial of Vitamin D₃ Supplementation on Body Fat Mass in Healthy Overweight and Obese Women. Nutr J. 2012 Sep 22;11:78. doi: 10.1186/1475-2891-11-78.
- Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, Ida H. Randomized Trial of Vitamin D Supplementation to Prevent Seasonal Influenza A in Schoolchildren. Am J Clin Nutr. 2010 91:1255-60. Epub 2010 Mar 10.
- Wilkins, Consuelo H. and Yvette I. Sheline, et al. “Vitamin D Deficiency Is Associated with Low Mood and Worse Cognitive Performance in Older Adults.” American Journal of Geriatric Psychiatry 14 (2006): 1032-40.
Writer Bio
Joe King began writing fitness and nutrition articles in 2001 for the "Journal of Hyperplasia Research" and Champion Nutrition. As a personal trainer, he has been helping clients reach their fitness goals for more than a decade. King holds a Bachelor of Science in kinesiology from California State University, Hayward, and a Master of Science in exercise physiology from California State University, East Bay.