While vitamin D is critical for optimal health, it’s important to note that excessive intake, particularly through supplementation, may increase your risk of vitamin D toxicity or hypervitaminosis D. This condition is generally caused by megadoses of vitamin D supplements—not by diet or sun exposure.
Symptoms of vitamin D toxicity may include (9):
- Nausea
- Vomiting
- Weakness
- Frequent urination
More serious health risks can include (9):
- Kidney damage
- Kidney stones
- Heart disease
- Calcification of soft tissues
Fortunately, to reach that level of toxicity, you would need to take a dosage of around 60,000 IUs—far more than any doctor would recommend.
The frequency of vitamin D dosing can also impact the risk of toxicity. For instance, some studies suggest that daily or weekly dosage regimens are less likely to cause toxicity compared to large, single doses. However, there is still ongoing research in this area.
As vitamin D is fat-soluble and stored in the body for long periods, it's essential to ensure intake is carefully regulated and not excessive. Therefore, it's always advisable to consult with a healthcare professional before starting or changing a vitamin D supplementation routine. They can provide personalized advice based on individual health needs and circumstances.