I read with great interest the excellent review article “Calcium supplementation, osteoporosis and cardiovascular disease” by Drs. Meier and Kraenzlin . They note several mechanisms linking calcium supplements with cardiovascular disease and I would like to add an additional point to this review. In recent years, several authors have included vitamin K as a possible protective factor, interacting with calcium and vitamin D in the maintenance of both bone and cardiovascular health . There are two main forms of vitamin K: vitamin K1 (found in vegetables) and vitamin K2 (produced by bacteria in the intestine and in fermented foods) . From a theoretical point of view, vitamin K might potentially decrease the burden of vascular calcifications by maintaining an adequate activity of matrix Gla protein, a vitamin K2 dependent, gamma-carboxylated protein which inhibits vascular calcification . In the Rotterdam Study, an adequate intake of vitamin K2 was associated with reduced risk of coronary heart disease and severe aortic calcification . Likewise, oral anticoagulant treatment with warfarin antagonises vitamin K, and several studies have shown an association between warfarin therapy and severe cardiovascular calcifications [5–7]. It is therefore plausible that, among other mechanisms, without an adequate vitamin K2 intake, the increased calcium intake through supplementation could have a detrimental effect on cardiovascular health through increased vascular calcification.
Reply to this Letter to the Editor:http://www.smw.ch/content/smw-2011-13301/
Correspondence: Francisco José Fernández-Fernández, MD, firstname.lastname@example.org
1 Meier C, Kraenzlin ME. Calcium supplementation, osteoporosis and cardiovascular disease. Swiss Med Wkly. 2011;141:w13260 http://www.smw.ch/content/smw-2011-13260/ .
2 Vermeer C, Braam L. Role of K vitamins in the regulation of tissue calcification. J Bone Miner Metab. 2001;19:201–6.
3 Fusaro M, et al. Vitamin K, bone fractures, and vascular calcifications in chronic kidney disease: an important but poorly studied relationship. J Endocrinol Invest. 2011;34:317–23.
4 Geleijnse JM, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: The Rotterdam Study. J Nutr. 2004;134:3100–5.
5 Holden RM, et al. Warfarin and aortic valve calcification in hemodialysis patients. J Nephrol. 2007;20:417–22.
6 Krüger T, Floege J. Coumarin use in dialysis patients with atrial fibrillation – more harm than benefit? Nephrol Dial Transplant. 2009;24:3284–5.
7 Schurgers LJ, Aebert H, Vermeer C, Bültmann B, Janzen J. Oral anticoagulant treatment: friend or foe in cardiovascular disease? Blood. 2004;104:3231–2.
Published under the copyright license CC BY-NC-SA: This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.