What’s Too Much Vitamin D?
Can you have too much vitamin D?  And, if so, what are the side effects of vitamin D? The detrimental effects of vitamin D deficiency are well known and garnering more and more attention in the medical news. But, like nearly everything else too much of a good thing can be detrimental too, and the same appears true with vitamin D as well.  But, it’s hard to get too much vitamin D in my experience. The good news is levels of vitamin D are easy to obtain so there is little risk of getting too much vitamin D if being properly monitored.
A recent study involving 132,000 participants presented at the annual meeting of the American Heart Association showed that higher than normal levels of vitamin D can cause atrial fibrillation, an abnormal heart rhythm. In that study vitamin D levels above 100 ng/dl was considered excessive.
In patients with kidney disease too much vitamin D can raise calcium levels in the blood increasing the risk of hardening of the arteries. Â Vitamin can also increase calcium in patients with sarcoidosis and histoplasmosis. Â Deposition of calcium can be prevented or minimize by obtaining adequate amounts of vitamin K2 which keeps calcium in the bone and prevents it from depositing the blood vessels. Â See our post “Vitamin K: Protect Your Bones and Prevent Cardiovascular Disease“. Individuals taking the blood thinner warfarin should not take vitamin K without consulting with their doctor.
Though vitamin D levels above 30 ng/dl are considered normal, more and more evidence suggests that levels between 50 ng/dl and 70 ng/dl are optimal. And, an increasing number of physicians are recommending levels in this range.
How Much Vitamin D Should I Take?
When recommending vitamin D dosing it’s important to recognize that someone in a bathing suit will make 10,000 units of vitamin D after being exposed to bright sun for 30 minutes. Â So, there should be little concern with taking more than the 400 IUs to 800 IUs many doctors still recommend. Â Because vitamin D levels are easy to monitored there’s no reason to guess on the dose. Â Take as much as you need to get your levels in the optimal range of 50 ng/dl to 70 ng/dl. Â Many individuals will find that they will need to take 5,000 IUs a day and some even 10,000 IUs a day.
Vitamin D levels will fluctuate and are somewhat seasonal depending on how much sunlight you get. Â There is little benefit from the sun on vitamin D production between November through February as the sun sits too low in the sky. Â So you may need to increase your vitamin D dose during those months. In the end, too little vitamin D is far more common and far more detrimental than too much vitamin D.
See related articles.
“What Foods are High in Vitamin D?”
“Vitamin D Deficiency Symptoms”