When it comes to heart disease, everyone thinks of cholesterol. What most people don’t know is that vitamin D deficiency is also linked to heart disease. Is there any scientific evidence to show the relationship between vitamin D deficiency and heart disease?
Evidence For The Link Between Vitamin D Deficiency And Heart Disease.
Scientific evidence to show the link between vitamin D deficiency and heart disease continues to grow. In an article (l) published in 1989 in Lancet, a respected British Medical Journal, a researcher noted a relationship between latitude and heart disease: the farther you live from the equator, the lower you are in vitamin D and the higher your risk for heart disease.
Over the years, numerous studies continue to show a relationship between low vitamin D level and heart disease. However, this vital information hardly received any public attention until 2008 when two studies finally got the attention of the news media.
In the first study (2), published in January 2008 in Circulation (the official journal of the American Heart Association), researchers of Framingham Heart Study in Framingham, Massachusetts followed 1739 participants for the development of heart disease. The mean follow-up was 5.4 years. These researchers found a nearly 2-fold increase in the risk for heart disease in individuals who had a low level of vitamin D.
In the second study (3), published in the June 9, 2008 issue of the Archives of Internal Medicine (the official journal of the American Medical Association), investigators from Harvard School of Public Health in Boston, Massachusetts looked at the level of vitamin D in 18,225 men in the Health Professionals Follow-up Study: These men were free of any heart disease at baseline. During a 10 year follow-up period, 454 men developed a heart attack. The results were stunning: the lower the vitamin D level, the higher the risk for heart attack. Men whose 25 (OH) vitamin D level was at least 30 ng/mL (75 nmol/L) had roughly half the risk of a heart attack compared to men who had a 25 (OH) vitamin D level below 30 ng/mL (75 nmol/L).
An excellent study (4) was published in 2012 in the American Journal of Cardiology. In this study, researchers from the University of Kansas Medical Center and Hospital in Kansas City, Kansas, studied 25 (OH) vitamin D level in 10,899 patients. Only 3,294 (29.7%) were in the normal vitamin D range (> 30 ng/mL or 75 nmol/L)) and 7,665 (70.3%) were deficient.
Vitamin D deficiency was associated with several cardiovascular- related diseases, including hypertension, coronary artery disease, cardiomyopathy, and diabetes. In addition, vitamin D deficiency was a strong independent predictor of all-cause death. Patients whose 25 (OH) vitamin D level was less than 30ng/mL (75 nmol/L), were at 2.6-fold increase risk of overall mortality.
An excellent study (5) from Medical University of Graz, Austria, was published in the Journal of Clinical Endocrinology and Metabolism in 2008. These researchers from Austria measured 25 (OH) vitamin D levels in 3299 Caucasian patients who were routinely referred to coronary angiography. During a median follow-up time of 7.7 years, 116 patients died due to heart failure and 188 due to SCD (Sudden Cardiac Death). Their findings were amazing: 25 (OH) vitamin D level was inversely correlated with congestive heart failure. In other words, the lower the vitamin D level, the higher the risk of heart failure. In addition, there was a 2.84-fold increased risk for death due to heart failure, and a 5-fold increased risk for SCD (Sudden Cardiac Death) in patients with severe vitamin D deficiency (25 (OH) vitamin D <10 mg/mL or 25 nmol/L.)
A provocative study (6) published in the May 2013 issue of Coronary Artery Disease, comes from Istanbul School of Medicine in Istanbul, Turkey. In this study, researchers investigated 222 patients for coronary artery blood flow rate, endothelial function (endothelium is the lining of the blood vessel wall) and carotid intima-media thickness, which is a measure of atherosclerosis (hardening of the arteries). They measured 25 (OH) vitamin D level in all of these patients.
Vitamin D level was low (less than 30 ng/mL or 75 nmol/L)) in 49% of the patients. They found a strong correlation between low vitamin D status, and slow coronary flow, endothelial dysfunction and atherosclerosis, all of these parameters indicate high risk for a heart attack.
Is There Evidence To Show That Vitamin D Supplementation Can Reduce Heart Disease?
The answer is yes.
In the same study (4) from University of Kansas Medical Center and Hospital, vitamin D supplementation was associated with a 61% increase in survival. The author concluded vitamin D deficiency was associated with a significant risk of cardiovascular disease and reduced survival. Vitamin D supplementation was significantly associated with better survival, specifically in patients with documented deficiency.
Another study (7) was published in European Journal of Heart Failure in 2012, in which researchers from Hadassah University Hospital in Jerusalem, Israel, evaluated the level of 25 (OH) vitamin D in 3009 heart failure patients. Only 8.8% of these patients had their vitamin D level above 75 nmol/L (which is equal to 30 ng/ml). Vitamin D deficiency was associated with increased mortality and vitamin D supplementation reduced mortality by 32%.
How Vitamin D May Prevent Heart Disease.
A provocative study (8) was published in 2009 in Circulation. These researchers from Washington University School of Medicine in St. Louis, Missouri, looked into the mechanism of how vitamin D may prevent coronary heart disease. Narrowing of the arteries develops due to accumulation of LDL cholesterol in the specialized cells in the arterial wall called macrophages. Once macrophages are ballooned out with LDL cholesterol, these are called foam cells, which then give rise to the formation of plaque in the arterial wall. These investigators found that vitamin D was able to prevent the uptake of LDL cholesterol by the macrophages and prevent the formation of foam cells. An amazing discovery!
In addition, vitamin D has been shown to decrease inflammation and insulin resistance, two other important mechanisms involved in the development of coronary heart disease.
In the last three decades, heart disease has become so prevalent that it’s the number one killer in the USA. During the same time period, vitamin D deficiency has grown to epidemic proportions. Compelling scientific evidence indicates that vitamin D appears to be a significant factor in heart disease. Vitamin D is cheap, has virtually no side-effects and has many benefits in addition to cardiovascular benefits. Isn’t it time to get on board and take charge of your vitamin D needs?
In addition to diet and exercise, you should consider taking vitamin D supplements in order to prevent heart disease.