Magnesium

Reffelmann et al. Low serum magnesium concentrations predict cardiovascular and all-cause mortality. Atherosclerosis 219:280-4, 2011 LINK

Larsson et al. Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies. Am J Clin Nutr. 95:362-6, 2012 LINK

Chiuve et al. Plasma and dietary magnesium and risk of sudden cardiac death in women. Am J Clin Nutr. 93:253-60, 2011 LINK

Chiuve et al. Dietary and plasma magnesium and risk of coronary heart disease among women. J Am Heart Assoc. 18; 2:e000114, 2013 LINK 
Ochsenham, Peter; Vormann, Professor Juergen. The Magnesium Deficiency Crisis: Is This the Worlds Number One Mineral Deficiency? (p. 84). madhouseMEDIA. Kindle Edition.