The "sunshine vitamin," vitamin D is manufactured by the skin during sun exposure. Consequently, vitamin D levels tend to be lower in the winter and in people living at low altitudes or high latitudes. Coincidently or not, the risk of heart attack is also higher during the winter and at low altitude and high latitudes.
In this latest study, investigators found that men with vitamin D levels of at least 30 ng/mL had half the risk of heart attack as men whose levels were less than 15 ng/mL. Less than a quarter of the men in this study had vitamin D levels of 30 or higher. This is because it is difficult to reach these high levels without substantial sun exposure; diet alone is unlikely to produce such levels.
Even taking supplements for vitamin D may not get you there. About 3000 IU per day of vitamin D would be required to reach blood levels of 30 ng/mL, while current dietary recommendations are for only 200 - 600 IU per day.
Of course, an association does not prove cause-and-effect. The investigators note that if a true cause-and-effect relationship can be established between vitamin D and the risk of heart attack, it may be necessary to revisit current dietary recommendations for this vitamin.
In the meantime, while waiting for definitive studies to be planned, funded, conducted, analyzed and reported, men with an increased risk of heart disease might want to consider getting a bit more sunshine.
Giovannucci E, Liu Y, Hollis BW, and Rimm EB. 25-hydroxyvitamin D and risk of myocardial infarction in men. A prospective study. Arch Intern Med 2008; 168:1174-1180.
Dear Dr. Rich:
It is absolutely ludicrous that the traditional medical community did not make the inferences regarding sunshine, latitiude, altitude, and cardiac health with regard to Vitamin D decades ago. To cite these anecdotes now is to portray themselves as “Keystone Kardiologists” who were previously unable fathom even the most overwhelming of practical observations without the benefit of a million-dollar study behind it.
I must admit I was initially skeptical about Vitamin D when I first heard Dr. Davis of Track Your Plaque extol its virtues in his clinical practice over a year ago. However, it is heartening to find the traditional community was only 18 months behind the times on Vitamin D as opposed to the more typical 18 years as it has been with heart scans a situation many blame in Mr. Russert’s death!
Regards,
HeartHawk
I found a blog post that makes an interesting argument that some of the studies showing lower Vit. D linked to increased mortality in osteoporosis and autoimmune disease are showing an effect of infection and Vit. D receptor disregulation rather than simple deficiency.
You won’t find any actual research that shows vitamin D + calcium increases bone density above calcium alone, though some people
still assert that conclusion. Vitamin D raises blood levels of calcium, yes. But not bone density.
Many people with low 25D have high 1,25D which is a product of 25D
That argues against deficiency in some cases. And in favor of infection + occasionally dysregulation of the Vitamin D Receptor resulting in overproduction of
1,25D from 25D (which leads to low levels of 25D, which appears like deficiency)
bacteriality.com/2007/09/15/vitamind/
They say high levels of 25D deactivates the Vitamin D receptor based on molecular modeling, though. That part I question. How much D3 supplementation does it take to maximize cathelidicin production?
I cannot find an answer to that question, and it should be simple.