New Study Gives Insight into How Much Vitamin D Might Be Too Much, but More Importantly Just How Safe High Doses of Vitamin D Actually Are
A new study reported at the American Heart Association Scientific Sessions in Orlando this week indicates that “too much” vitamin D is associated with atrial fibrillation (irregular heart beat). However, the findings are not as bleak as it sounds. In fact, the results are actually reassuring in regard to the safety of high dose vitamin D! Despite some who try to spin the results in favor of minimal or no supplementation, this study, lead by Dr. T. Jared Bunch, a heart rhythm specialist at the Intermountain Medical Center Heart Institute in Utah reaffirms the safety of supplementing with high doses of vitamin D. So, what daily dose is safe, and how much was “too much?”
That depends upon the person; it could be 4000 IU/day, it could be 15,000 IU/day. The optimal dose for a particular person is whatever level is necessary to maintain vitamin D blood levels between 50 – 100 ng/ml.
With so many people taking supplements, and particularly vitamin D lately this study sheds light on what problems may occur with taking “too much.” Dr. Bunch said, “There are both benefits and harm to taking vitamin supplements of all kinds. Our goal is to determine a safe dose and usage range so patients can understand what amount is healthy, and what amount may be toxic.”
In following more than 132,000 subjects the researchers discovered a two and half times greater risk of developing atrial fibrillation when blood levels were greater than 100 ng/ml than compared to those with normal vitamin D levels.
The good news: the atrial fibrillation was reversable. Secondly, to obtain a blood level above 10,000 ng/ml it usually requres supplementing with more than 10,000 IU/day. Therefore, a healthy and safe daily dose of vitamin D could be any dose between 2000 and 10,000 IU/day, depending upon the person.
One suggestion is to have your vitamin D blood levels checked in Spring and Fall, and take whatever dose is necessary to keep your level between 50 and 100 ng/ml to obtain the myriad benefits. This author takes a daily total of 12,000 IU/day of vitamin D3, which results in a blood level of 85 ng/ml. For others, it might be different, which is why it is important to check your vitamin D levels.