On the 30th May I wrote about the importance of Vitamin D for health and concentrated mainly on the link to cancer prevention.
Yesterday a study was published in the Archives of Internal Medicine(1) which adds to the growing body of research that links low vitamin D levels to poorer heart health.
This particular study involved a group of 18225 middle aged and older men (aged 40-75 years). The men were free of diagnosed heart disease at the initial blood collection. They were then followed for 10 years and in this time 454 developed heart attacks (which were either fatal or non fatal). The study scientists then compared the blood levels of vitamin D in those men who had suffered a heart attack to a group of 900 similar men (matched for certain factors such as age and smoking status) who had not. The results showed that men with low blood levels of vitamin D were at increased risk of heart attack compared to men with sufficient levels. Even men with intermediate blood levels of vitamin D were at increased risk of heart attack.
The findings are significant as the scientists adjusted the results to exclude a whole host of other possible confounding factors such as family history of heart attack, weight (Body Mass Index), alcohol consumption, physical activity levels, history of diabetes, blood pressure, ethnicity, omega 3 fatty acid intake and cholesterol levels. Even when these factors were taken into account the men with low vitamin D levels were twice as likely to experience a heart attack than those with high vitamin D levels.
The authors of the study conclude that “Low levels of 25(OHD) [vitamin D] are associated with a higher risk of myocardial infarction [heart attack] in a graded manner, even after controlling for factors known to be associated with coronary artery disease”
Previous studies have linked low vitamin D levels to atherosclerosis (hardening of the arteries), congestive heart failure and high blood pressure. As I mentioned in my previous post on vitamin D many of us in the UK may not have adequate levels of vitamin D in our blood. A supplement of 12mcg/d (around 500iu) could be useful to those who rarely get out in the sunlight or during the autumn and winter months.
It is not entirely understood why vitamin D is so important for the health of the heart. There are indications that vitamin D acts to reduce the production of pro-inflammatory chemicals (cytokines) which are linked to heart disease and may even increase the production of anti-inflammatory chemicals which are protective. Vitamin D may also have an effect on certain hormones which play an important role in the regulation of blood pressure.
(1)Giovannucci E et al. 2008. 25-Hydroxyvitamin D and risk of myocardial infarction in men: a prospective study. Arch Intern Med. 168:1181-1187
Written by Ani Kowal
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- Mediterranean diet shown to help those with heart problems
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