Too much of this common supplement can be toxic

Too much of this common supplement can be toxic

As people turn to supplements to get more vitamin D, can they overdo it?

The answer, according to medical professionals, is yes.

Vitamin D is found naturally in foods such as milk and fatty fish, but it’s also available in capsule form – a convenient source if taken responsibly.

“More vitamin D is not always better. It’s rare, but when people overdose on vitamin D supplements – either by taking one very large dose over 300,000 international units (IU) or taking 10,000 IU for three or more months, it can cause dangerous levels of calcium to build up in the blood,” said Dana Artinyan, a registered dietitian at Advocate Illinois Masonic Medical Center in Chicago.

When vitamin D is naturally absorbed through food and sun exposure, the body is able to regulate the needed amount. That’s not always the case when it’s consumed in capsules in larger quantities.

Bottles containing a potent 10,000 IU each can easily be found on drugstore shelves today, making it critical for people to pay close attention to the doses they’re consuming.

“Symptoms of excessive calcium in the blood include loss of appetite, excessive thirst, abdominal pain, muscle weakness or bone pain. I recommend that most of my adult patients take 1,000-2,000 IU daily. If you are deficient in vitamin D, consult your doctor to come up with a plan together,” said Artinyan.

If you notice any of these signs, call your physician immediately.

To stay on the safe side, aim to get most of your daily vitamin D from natural food sources instead. Salmon, tuna and fortified dairy products are all great options. Some foods labels are even starting to include vitamin D amounts, making it easier for many to stay healthy – and safe – this winter season.

To find a trusted dietitian or to find a primary care physician to consult, search our network of professionals. Click here for Illinois and here for Wisconsin.

Related Posts



  1. My endocronologist has me on 5,000IU a day for the past four years. My vitamin D blood level is around 50 which is midrange. I haven’t had a cold in three years or the flu. He told me every person he tested has been deficient. Low levels are very common in the Chicago area because we get a lack of sun and wear sunscreens when we are in the sun in summer. I suggest that you get your vitamin D level tested when you get your regular blood tests; that’s how you know for sure. I bet you will be deficient! Vitamin D has been shown to reduce some types of cancer and low levels can lead to bone loss, and even cause depression among many other things. Never heard of anyone overdosing from what my doctor’s have told me. I do reduce my D to 2,000 per day during the Summer months.

  2. I am taking about 2,000 IU. I’ve heard African Americans might need more. Is that true?

  3. It’s almost comedic watching medical professionals contradict each other in these things. Best at guessing next to meteorologists.

  4. What about adding vitamin K2 if you take vitamin D3 capsules to manage the calcium situation?

  5. Study after study shows that proper supplementation is important to our health, more so than ever because our food does not have the same nutrients it once did. That is a fact. I say proper supplementation, because not all supplements are created equal. We need supplementation that has the right delivery system, that is bioavailable, and can be absorbed. We need to put a bigger emphasis on the importance of gut health. I hope to be a voice of change in our organization that leads to team members and patients understanding what improving nutrition, decreasing toxins, improving gut health and proper supplementation can do for their long term health. I am an educator about this outside of the walls of our organization, I pray that someday I will have the opportunity to educate within our walls. Consumers want this. It is time for our organization to meet this demand.

Subscribe to health enews newsletter

About the Author

Katie Wilkes
Katie Wilkes

Katie Wilkes, health enews contributor, is a freelance public affairs specialist at Advocate Health Care and Aurora Health Care. A DePaul University alum, she brings a decade of experience in media relations and content development to her role. Katie is also the co-founder and Emmy-nominated producer at Freeheart Creative, dedicated to sharing stories of brave women around the world. In her spare time, you can find her zen-ing out at a yoga studio and chilling with her 14-year old West Highland Terrier.