What Can Too Much Vitamin D Do
Medically reviewed by Rosanna Sutherby, PharmD on September 18, 2020. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
Vitamin D is a key nutrient because it helps your body absorb dietary calcium so you can have strong, healthy bones. That's why it's important to get enough of it. But it's also possible to get too much vitamin D—referred to as vitamin D toxicity. While this is rare, it can still be useful to know the common signs of too much vitamin D—particularly if you take vitamin D supplements regularly.
Here, we'll discuss some of the symptoms that can develop if you experience vitamin D toxicity, so read on (and if you'd like to check your vitamin D levels from the comfort of home, consider trying our vitamin D test kit).
Signs and symptoms of too much vitamin D
Signs you're getting too much vitamin D may include:
- Nausea
- Vomiting
- Weakness
- Headache
- Frequent urination
- Painful muscles
- Kidney damage and kidney stones
- High blood pressure
Understanding vitamin D toxicity
Also called hypervitaminosis D, vitamin D toxicity is uncommon and occurs when your body's vitamin D levels are too high. Vitamin D toxicity typically develops from over-supplementation, as opposed to diet or sun exposure. With the sun, your body can regulate the amount of natural vitamin D that's produced. And when it comes to food, naturally-occurring vitamin D isn't common—and fortified foods don't usually contain enough vitamin D to lead to toxicity.
How much vitamin D do you need?
Wondering, "How much vitamin D do I need?" The recommended dietary allowance (RDA) for people in different age groups is shown below. These recommendations come from the National Academies of Sciences, Engineering, and Medicine. Based on a number of factors, however, your healthcare provider may suggest doses that are higher or lower than what's listed—so consider asking your provider for their recommendation. Note that the amount of vitamin D in foods and supplements is usually expressed in terms of International Units (IU), so "IU/day" refers to "International Units per day."
Recommended dietary allowance (IU/day) for vitamin D followed by the upper intake level:
Infants 0-6 months
- 400 IU/day for adequate intake
- Upper intake level of 1,000 IU/day
Infants 6-12 months
- 400 IU/day for adequate intake
- Upper intake level of 1,500 IU/day
Children 1-3 years old
- Recommended dietary allowance of 600 IU/day
- Upper intake level of 2,500 IU/day
Children 4-8 years old
- Recommended dietary allowance of 600 IU/day
- Upper intake level of 3,000 IU/day
People 9-70 years old
- Recommended dietary allowance of 600 IU/day
- Upper intake level of 4,000 IU/day
People over 70 years old
- Recommended dietary allowance of 800 IU/day
- Upper intake level of 4,000 IU/day
Women 14-50 years old who are pregnant or lactating
- Recommended dietary allowance of 600 IU/day
- Upper intake level of 4,000 IU/day
In some cases, healthcare providers may prescribe higher doses to treat a vitamin D deficiency, though these numbers provide a good guideline. Of course, talk with your healthcare provider to learn what amount of vitamin D intake they recommend for you.
How can you measure your vitamin D intake in International Units (IU)?
If you're taking a vitamin D supplement, the amount of vitamin D will likely be listed on the supplement's nutritional label, either in International Units or micrograms (2.5 micrograms = 100 IU). Micrograms may be abbreviated as "mcg."
Vitamin D amounts aren't always listed directly on the labels of food items. However, labels often do list the percent Daily Value (DV), which reflects the amount of vitamin D in a serving of that food as a percentage of 800 IU.
Finally, you can also get a sense of the vitamin D content of various kinds of food by visiting the National Institutes of Health's resource on vitamin D (see Table 3).
What can be done about vitamin D toxicity?
If vitamin D toxicity occurs, your healthcare provider may suggest restricting your dietary calcium intake. Treatment may also include discontinuing the use of any vitamin D supplement—at least temporarily.
Ways to get vitamin D
You can get vitamin D from sunlight exposure, dietary sources, and supplements.
Getting ample vitamin D through sun exposure can be straightforward, but you do need to make sure you don't get sunburned (by limiting how much time you spend out in the sun, for example).
In food, vitamin D can be found in beef liver, egg yolks, and fatty fish like salmon and tuna. There are also many fortified foods, like milk and dairy products, that provide your body with vitamin D.
Signs of inadequate vitamin D intake
Along with knowing the signs of too much vitamin D, it's a good idea to know the signs of inadequate vitamin D intake.
Inadequate vitamin D intake can result in signs and symptoms like:
- Fatigue
- Depression
- Weakness
- Joint pain
- Muscle pain
Studies have even shown that low vitamin D levels may be connected to higher risks of heart disease, diabetes, cancer, mood disorders, and dementia.
Benefits of testing your vitamin D levels
If you're experiencing any of the symptoms of vitamin D insufficiency noted above—or are experiencing signs of too much vitamin D—your intake may be imbalanced in some way. Testing your vitamin D levels can help you determine if your levels are normal or if you may need to make adjustments and have a discussion with your healthcare provider.
Our at-home vitamin D test kit lets you check your levels easily—it only requires a simple finger prick blood sample, and shipping is free both ways. Plus, you'll get to conveniently view your results on our secure, online platform just days after the lab receives your sample.
Related content
Vitamin D during pregnancy
When should you take vitamin D?
References
1. What is vitamin D toxicity? Should I be worried about taking supplements?. Mayo Clinic. URL. Accessed September 18, 2020.
2. Vitamin D. National Institutes of Health. URL. Accessed September 18, 2020.
3. Taking too much vitamin D can cloud its benefits and create health risks. Harvard Medical School. URL. Accessed September 18, 2020.
4. Vitamin D. NIH, Office of Dietary Supplements. URL. Accessed September 18, 2020.
What Can Too Much Vitamin D Do
Source: https://www.everlywell.com/blog/vitamin-d/signs-of-too-much-vitamin-d/
