A new study in the journal Coronary Artery Disease reports that vitamin D deficiency correlates with slow coronary function.
To date, there’s been quite a bit of research that has noticed high prevalence of vitamin D deficiency in patients with high blood pressure, coronary artery disease, peripheral artery disease, and stroke and in cardiovascular mortality. Researchers speculate that vitamin D may be helpful for heart health with a beneficial role in endothelial and smooth muscle function, inflammation, and regulation of the rennin-angiotension-aldosterone system.
In this present study, Dr. Fahrettin Oz and colleagues theorized that vitamin D deficiency might correlate with slow coronary flow. Slow coronary flow describes “delayed opacification of the epicardial coronary vessels.” People with slow coronary flow often have chest pain. Slow coronary flow is associated with heart attack, high blood pressure and sudden cardiac death.
The researchers examined 961 consecutive patients who underwent a coronary angiography for suspected ischemic heart disease at the hospital at Istanbul University. Ischemic heart disease describes low blood supply to the heart, usually due to coronary artery disease. 739 of the patients did not meet inclusion criteria (mainly because they had stenosis in at least one coronary artery), dwindling down the study population to 222 patients. This means that all patients in this study had normal or near normal coronary arteries.
The researchers measured many things, including vitamin D status and various markers of heart health. Here is what they found:
- The mean vitamin D level was 31.8 ng/ml. 47% of the study group had levels less than 30 ng/ml.
- The researchers’ theory proved correct. 12% of patients with vitamin D levels less than 30 ng/ml had slow coronary flow, compared to just 7% of patients with levels higher than 30 ng/ml.
- If you had a vitamin D level of less than 30 ng/ml, you were 3.5 times more likely to have slow coronary flow than those with higher levels (RR=3.5, p=0.01).
- Vitamin D was not significantly related to hypertension or diabetes.
The researchers conclude,
“To our knowledge, the present study is the first to investigate the association between vitamin D insufficiency and the slow coronary flow phenomenon. Our observational study found a significant association between the prevalence of slow coronary flow and low vitamin D levels independent of age, sex, and several other potential confounding factors.”
The researchers did not have a clear explanation for this relationship, other than it’s been observed that vitamin D may have widespread effects on cardiovascular health, including on proper endothelial function. Limitations of the study include its general observational study design and small number of subjects.
Patients with slow coronary flow are treated with nitrates, β-blockers, calcium channel blockers, and antiaggregant agents. Should vitamin D be added to the list as an add-on therapy? While the present study is not designed to answer this question, there is also no reason not to be sufficient in vitamin D anyhow. Future randomized controlled trials should be able to determine definitively if vitamin D can help treat slow coronary flow.