13/07/09 Emerging research suggests that nutritional factors including vitamin D, magnesium, and others may influence the risk and progression of cardiovascular disease. The new data on nutrition and heart disease were the topic of a recent symposium and are summarized in the July issue of The American Journal of the Medical Sciences (AJMS), official journal of the Southern Society for Clinical Investigation (SSCI). The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and biomedical intelligence for students, professionals, and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

"The prospect that macro- and micronutrients may play an important role in the appearance of diseases of the cardiovasculature and their progressive nature is both intriguing and provocative," according to the article's preface by Dr. Karl T. Weber. The article highlights key findings presented at the SSCI's Annual Scientific Session in New Orleans earlier this year. The symposium was presented in conjunction with the SSCI's Cardiovascular Club and the International Academy of Cardiovascular Sciences/North America.

Several recent studies have identified low vitamin D levels as a common problem with many adverse health effects, including increased rates of cardiovascular disease. People with vitamin D deficiency are at increased risk of high blood pressure, heart failure, and ischemic heart disease, according to Suzanne Judd, MPH, PhD, of University of Alabama at Birmingham and Dr. Vin Tangpricha of Emory University. In patients who already have heart disease, low vitamin D may increase the risk of high blood pressure or sudden death.

Vitamin D deficiency may also help to explain the apparent relationship between osteoporosis-related fractures and heart failure, according to Dr. Syed H. Raza and colleagues. Osteoporosis and heart failure are both common conditions in older adults and share several risk factors including low vitamin D. Pending further research to clarify this relationship, patients with heart failure need attention to their risks of osteoporosis and fractures.

So far, however, there is very little information on whether taking vitamin D supplements can avoid or reduce these risks. Rebecca B. Costello, PhD, of the National Institutes of Health's Office of Dietary Supplements outlines federal research initiatives to understand the effects of vitamin D on health. She urges rigorous scientific studies to clarify the relationship between vitamin D and cardiovascular disease, as well as other chronic diseases.

Could folic acid help prevent heart disease? Folic acid (vitamin B9) reduces levels of the amino acid homocysteine, which affects cardiovascular risk, according to Dr. Lydia A. Bazzano of Tulane University. However, studies have found that taking folic acid to reduce homocysteine does not lower cardiovascular risk in adults. Taking folic acid during pregnancy does appear to reduce the risk of congenital heart defects, however.

Low levels of nutrient magnesium may lead to a "cascade" of harmful inflammation-promoting events, according to Dr. Jay H. Kramer of George Washington University and colleagues. This may lead to disease of the heart muscle (cardiomyopathy), increasing vulnerability to injury from other forms of stress. Especially with the high rate of magnesium deficiency in the population, antioxidants and other medications in addition to magnesium supplements might help in reducing cardiovascular disease.

Patients with heart failure especially African Americans are prone to an imbalance of several nutrients, according to a presentation by Dr. German Kamalov and colleagues. The imbalance is accompanied by activation of certain hormones, leading to inflammation and wasting of soft tissues and bone. The authors discuss approaches to recognizing this nutritional imbalance, and suggest that a "polynutrient supplement" including calcium, magnesium, zinc, selenium, and vitamins D, B12, and B1 might play a role in heart failure management.

Despite the tantalizing new evidence, "The role of nutrition in the causation, prevention, and treatment of cardiovascular diseases is largely unexplored," Dr. Weber concludes. "Investigator-initiated, hypothesis-driven research conducted in a mode of discovery by a multidisciplinary team of basic and clinical scientists will undoubtedly open new frontiers and pave the way by identifying simple remedies that could advance the practice of medicine."