Lack of vitamin D increases risk of heart attacks

William Atkins
Sunday, 06 July 2008 19:55

Science - Health

Men with the lowest blood levels of vitamin D were found to be twice as likely to have a heart attack as men with the highest levels of vitamin D in the blood.

The researchers concluded, “Low levels of 25(OH)D are associated with higher risk of myocardial infarction in a graded manner, even after controlling for factors known to be associated with coronary artery disease.”

They also found that men with even intermediate levels of vitamin D had an increased risk when compared to those men with higher levels of vitamin D.

Vitamin D regulates levels of calcium and phosphorus in the blood. It also promotes bone formation and mineralization in the body, which provides for a strong skeleton.

A type of vitamin D (D₃) is produced in the skin that is exposed to sunlight. Only fish naturally contains vitamin D. Much of the vitamin D ingested by humans comes from food fortified with vitamin D, such as milk, soy milk, and breakfast cereals, or in vitamin supplements.

Bruce Hollis (Medical University of South Carolina, Charleston), a coauthor in the study, stated that too little vitamin D in the blood stream is “right up there with high blood pressure and smoking.” [Science News: July 5, 2008, page 9]

The researchers involved in the study are Edward Giovannucci, Yan Liu, Bruce W. Hollis, and Eric B. Rimm.

The authors are associated with the: Departments of Nutrition (Giovannucci, Rimm, Liu) and Epidemiology (Giovannucci and Rimm), Harvard School of Public Health, Boston, Massachusetts; Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston (Giovannucci and Rimm); and Department of Pediatrics, Medical University of South Carolina, Charleston (Hollis).

Lower-than-normal levels suggest a vitamin D deficiency. This condition can result from:

• Lack of sunlight exposure 
• Lack of adequate vitamin D in the diet
• Liver and kidney diseases
• Malabsorption
• Certain medicines, including phenytoin, phenobarbital, and rifampin

A vitamin D deficiency may lead to:

• Low blood calcium levels (hypocalcemia)
• Thin or weak bones (rickets, osteoporosis, and osteomalacia)
• High levels of parathyroid hormone (secondary hyperparathyroidism)