Scientists from the University of Eastern Finland found that taking higher than recommended doses of vitamin D for five years reduced the risk of atrial fibrillation in older men and women. Research published American Heart Journal.
The five-year study included 2,495 people: men age 60 and older and women age 65 and older. One group received a placebo, the second group received 40 micrograms (1600 IU) of vitamin D3 per day, and the third group received 80 micrograms (3200 IU) of vitamin D3 per day. According to Finnish medical guidelines, the recommended dose of vitamin D3 for the elderly is up to 20 mcg (800 IU).
Initially, study participants were not diagnosed with cardiovascular disease or cancer and filled out questionnaires about their lifestyle and diet.
During the five-year study, 190 participants were diagnosed with atrial fibrillation: 76 in the placebo group, 59 in the 40 mcg group, and 55 in the 80 mcg group. The risk of atrial fibrillation was 27% lower in the 40 mcg group and 32% lower in the 80 mcg group compared to the placebo group. The study found no association between vitamin D3 intake and the incidence of other cardiovascular disease or cancer.
One year after the start of the study, the mean blood concentration of vitamin D3v was 100 nmol/L in the 40 µg group and 120 nmol/L in the 80 µg group. There were no significant changes in vitamin concentrations in the placebo group.
Previous studies examining the effect of vitamin D3 on the heart at doses of 10 mcg (400 IU) or 50 mcg (2000 IU) per day showed no effect in reducing the risk of arrhythmias. Because of this controversy, more research is needed before changes to physician recommendations can be made.
Atrial fibrillation (atrial fibrillation) is the most common type of arrhythmia. This disease greatly increases the risk of stroke, heart failure, and death. Previous studies have shown that vitamin D affects auricular structure and electrical function of the heart. Therefore, scientists speculated that vitamin D might prevent atrial fibrillation.
previous studies showedthat a diet high in omega-3 fatty acids may reduce the risk of atrial fibrillation in older men.