health news
March 6, 2012 posted by

Too Much Of A Good Thing? A Closer Look At Vitamin D

Those of you on the vitamin D bandwagon should take note of a new study showing that too can lead to increased cardiovascular inflammation. “People should have their D levels tested before taking vitamin D supplements and tested again a few times a year if they stay on them”, says Muhammad Amer, MD, an assistant professor of internal medicine at Johns Hopkins University School of Medicine. “They should not be ignoring the fact that D is a steroid-like hormone and may be harmful at some level.”

I’ve posted on the potential pitfalls of randomly jacking your diet with vitamin D a couple times recently. Most of us who spend time outdoors have no need to supplement it. However, as per usual in the supplement industry, there’s always something trendy that everyone’s recommending. And while the theoretical downside of overdosing D has been known, until now there’s hasn’t been much quantifiable data that it was a realistic possibility.

A study published in the American Journal of Cardiology in January has changed this. It looked at 15,000 healthy adults age 18 to 85 and found that, while increasing levels of D in the blood are associated with decreased cardiovascular inflammation to a point, once D levels go beyond that point, inflammatory markers actually begin to rise.

New Hope 360 reports:

This indicates a growing risk of stiffening blood vessels and other cardiovascular problems. This latest research is among several new studies that suggest, as Virginia Moyer, MD, chair of the U.S. Preventive Services Task Force, recently put it: “The nutrient falls into the category of something that both benefits and harms.”

They follow the news with an interview with Dr. Amer, the study’s lead author. Click on the quote to read the entire article,

Vitamin D is beneficial for your cardiovascular health because it curbs inflammation, which is an underlying reason for atherosclerosis (hardening of the arteries). You should be on it if you are a candidate (because your D levels are low), but you should not keep on taking it indefinitely without keeping track of your levels. Again, at certain levels in the blood, vitamin D may become pro-inflammatory. If you can be on vitamin D rather than being on expensive statin drugs that compromise your kidney, liver and muscle, why not? It can definitely benefit you—it just has to be used judiciously.


  • is 2000 IU to much of a daily dose?

  • I'd say it's high unless you never get outside. 400IU is the RDA, not that it means much, and I think from your name you're the super fit guy so you can likely use more. If it were me I'd dig into the study cited here and see what kind of levels were results in the reverse of inflammation. Keep in mind if you search the net there's a lot of bad info around. In fact, my wife's TWO docs both recommend her to take a vit D supplement and they have not offered to test her levels. And she's outside a lot. So there is definitely misinformation out there even amongst the informed.

  • "This information is coming from Pharmaceutical journals and is passed down from my mother (the pharmacist) to me. Not only do I take a multi-vitamin with 400IU's of D3 in it, but I also take another 1000IU tablet as well. Anything over 2000IU's your body will just flush out of your system anyways, so if you are buying into the 2500IU or 4000IU tablets, it's a waste of money"This post was on one of my old blogs. If true then even the watchdog industries are spreading bad info. Hopefully with studies like this one it will start to change.

  • The other part of this that hasn't been addressed is the fact that sunscreen significantly blocks vitamin d production. This means that while people may be spending a lot of time outside, they might still be deficient in vitamin d if they're using heavy amounts of sunscreen.

  • if you click the links I covered that last time.

  • alright Thanks Steve and yes lol i am that fit guy that did the 11/11/11 challenge with you back in November 🙂 but i was just curious about if i was taking to much but i guess it's all good then since i'm active. being a graphic designer tho for my daily job i am inside most of the day tho so my sun exposer is actually pretty rare so it's probably a good idea that i take the extra anyway. thanks again!

  • I was pale before it was cool.

  • My doc just tested all my levels and really helped me understand core vitamins. He said A,D,E and K are NOT water soluble so therefore a person can take to much of them and cause secondary consequences. The rest of the core vitamin family such as B and C are water soluble and therefore your body absorbs what it needs and excretes the rest- meaning you can't overdose on it. I love this article! I have a good friend taking 5,000 iu a day of D bc her dr. Told her to do I'm always giving her articles with D side effects!

  • I was deficient on my labs (25), so my doc put me on 20,000 IU per day. Did the trick. I'm now at 86, so we're dialing down to half the dose and will check again. He wants me to stay between 60-70.

  • I hesitate to make decisions based on one study. Although the large number of participants theoretically makes this a really impressive sample size, it can also artificially amplify positive results. I would need to read the study myself, because there was no mention of controlling for age, nor I believe ethnicity. And there could be some statistical issues that account for the results rather than a true effect. There is a difference between something being statistically significant in a study this huge, versus realistically relevant. I'll look forward to future research, especially data that replicates this finding.

  • You should read the study. I read studies all the time and it's almost amazing (except I've come to expect such things) how often the actual findings are misrepresented. In this case I did not read it because, to me, the study validates what we've theoretically known (and too often ignored in my opinion) all along, that care should be used when taking fat soluble vitamins. Not care, actually, as that's too strong. I mean not blantantly ignoring all warnings and living on the "if some is good an absurd amount must be great" ideal.

Leave a Reply

Your email address will not be published.

* Copy This Password *

* Type Or Paste Password Here *