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Comment & Response |

Dietary and Supplemental Calcium Intake and Mortality

Elke Theuwissen, PhD1; Vladimir Badmaev, MD, PhD2; Cees Vermeer, PhD1
[+] Author Affiliations
1VitaK, Maastricht University, the Netherlands
2NattoPharma ASA, Oslo, Norway
JAMA Intern Med. 2013;173(19):1841. doi:10.1001/jamainternmed.2013.9260.
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To the Editor In a recent report, Xiao et al1 discuss the outcome of the National Institutes of Health (NIH)–AARP Diet and Health Study, which evaluated the role of calcium intake on cardiovascular health. The outcome of the study revealed that intake of 1000 mg/d of supplemental calcium was associated with significant increase in cardiovascular mortality in men but not in women.

Arterial calcification is an actively regulated process with a key function for the vitamin K–dependent matrix Gla protein (MGP).2 Mature MGP is a powerful inhibitor of soft-tissue calcification and is abundantly expressed by vascular smooth muscle cells. The vitamin K–dependent step in MGP synthesis is the carboxylation of 5 glutamate residues into γ-carboxyglutamate (Gla), which are essential for MGP’s calcification inhibitory activity. In healthy adults, at least 20% of plasma MGP occurs in the uncarboxylated, inactive form. Conformation-specific assays have demonstrated that circulating uncarboxylated MGP has a high predictive value for cardiovascular and overall mortality.2,3 Moreover, several independent population-based studies have shown that dietary vitamin K2 intake is inversely associated with cardiovascular disease and mortality.


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October 28, 2013
Qian Xiao, PhD; Yikyung Park, ScD
1Division of Cancer Epidemiology and Genetics, Nutritional Epidemiology Branch, National Cancer Institute, Rockville, Maryland
JAMA Intern Med. 2013;173(19):1841-1842. doi:10.1001/jamainternmed.2013.9232.
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