Too much vitamin D can lead to toxicity, also known as vitamin D hypervitaminosis. The popularity of vitamin D supplementation has increased in recent years. Since supplements often contain concentrated doses of a vitamin, they could cause your vitamin D levels to become too high over time—especially if you don’t have a deficiency.
Vitamin D is available from the sun and a few food sources. Many people also get their vitamin D through supplementation.
It is possible to get too much vitamin D over time. It’s a fat-soluble vitamin that builds up in your system. In comparison, water-soluble vitamins are excreted through urine when too much is taken. When vitamin D buildup occurs, it can lead to toxicity.
Below are the upper limits of vitamin D intake. Taking less than these amounts, unless prescribed by a healthcare provider, can help prevent toxicity.
| Age | Upper Limit |
|---|---|
| Infants 0 – 6 months | 25 micrograms (mcg) or 1,000 international units (IU) |
| Infants 7 – 12 months | 38 mcg or 1,500 IU |
| Kids 1 – 3 years | 63 mcg or 2,500 IU |
| Kids 4 – 8 years | 75 mcg or 3,000 IU |
| Kids 9 – 18 years | 100 mcg or 4,000 IU |
| Adults 19 and older | 100 mcg or 4,000 IU |
| Pregnant/breastfeeding people | 100 mcg or 4,000 IU |
If you consistently take too much vitamin D, you can develop signs of toxicity, such as:
- Nausea and vomiting
- Constipation
- Poor appetite
- Weakness
- Weight loss
- Confusion
- Disorientation
- Frequent urination
- Unsteady gait
- Dehydration
Although rare, vitamin D toxicity can also lead to a buildup of calcium, or hypercalcemia. This may occur when taking very high doses of vitamin D supplements. Hypercalcemia can lead to serious issues like kidney failure and abnormal heart rhythms. Symptoms of hypercalcemia may take weeks or months to appear.
About half of all people in the U.S. are not getting enough vitamin D, but this doesn’t necessarily mean you need to start taking a supplement. Instead, have your healthcare provider do a blood test to check your levels.
From there, your provider can advise you on how much vitamin D to take. Ideally, you will get your vitamin D from a mix of the sun, foods that contain vitamin D (like fatty fish, beef liver, fortified milks and juices, and egg yolks), and, if needed, supplements.
Here are the recommended daily intakes of vitamin D:
| Age | Recommended Amount |
|---|---|
| 0 to 12 months | 10 mcg (400 IU) |
| Kids 1 – 13 years | 15 mcg (600 IU) |
| Teens 14 – 18 years | 15 mcg (600 IU) |
| Adults 19 – 70 years | 15 mcg (600 IU) |
| Adults 71 and older | 20 mcg (800 IU) |
| Pregnant/breastfeeding people | 15 mcg (600 IU) |
