Friday, January 2, 2009

Serum vitamin D levels, heart attack and stroke: Vitamin D can save your life!

It has been some time since I posted anything about heart disease, and since I have been asked to send my agent something to present to Larry King, I thought I might as well post it as a blog, too. Suffice it to say that there is no blood test more important than vitamin D [calcidiol or 25(OH)D].

Two 2008 studies show the dramatic influence of blood vitamin D levels and the risk of heart attack. Dr. Thomas Wang and colleagues compared the risk of stroke and heart attack with serum-vitamin D levels and found a 62% increased risk in those with lowest levels compared to those with highest levels and also showed that those with low D levels and high blood pressure had double the risk.[1] Dr. Edward Giovannucci, of Harvard University, and his colleagues reported even more impressive results.[2] They found that men whose serum levels of vitamin D were less than 15 ng/ml had nearly 2.5 times the rate of heart attack as those whose levels were above 30. Their research also showed that mid-range vitamin D levels showed a mid-range risk of heart attack and stroke, meaning that vitamin D levels directly predicted the risk of heart attack at all levels. The researchers stated, “Low levels of 25(OH)D are associated with higher risk of myocardial infarction in a graded manner, even after controlling for factors known to be associated with coronary artery disease.”

Still other research showed that classic risk factors for cardiovascular disease were higher in those who ranked in the lowest quartile (fourth) of vitamin D levels compared to those whose levels were in the highest quartile.[3] Hypertension was 30% higher, diabetes 98% higher, obesity 129% higher and triglycerides 47% higher.

This idea is not really that new; it has simply been ignored. In 1990, a study in New Zealand found that those below the median level of serum vitamin D suffered 57% more heart attacks than those whose levels were above the median.[4] They also noted that the greatest number occurred in winter and spring, and that the reduced risk among those with higher levels pertained to all seasons. All of this indicates vitamin D deficiency as a major cause of heart disease. Do not ignore this information if you have a heart!

[1] Wang, T. et al. Vitamin D deficiency and risk of cardiovascular disease. Circulation 2008;117 pre-publication copy.
[2] Giovannucci, E. et al. 25-hydroxy-vitamin D and risk of myocardial infarction in men. Ann Intern Med 2008;168:1174-80.
[3] Martins, D. et al. Prevalence of cardiovascular risk factors and the serum levels of 25-Hydroxyvitamin D in the United States. Arch Intern Med 2007;167:1159-65.
[4] Scragg, R. et al. Myocardial Infarction is inversely associated with plasma 25-hydroxy vitamin D3 levels: a community-based study. Int J Epidemiol 1990;19:559-63.

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