From the Guidelines
Vitamin D toxicity, also known as hypervitaminosis D, is a rare but potentially serious condition that occurs when excessive amounts of vitamin D build up in the body, typically from supplement overuse, and can lead to hypercalcemia, hyperphosphatemia, and kidney damage. The effects of vitamin D toxicity can be severe and include symptoms such as nausea, vomiting, weakness, frequent urination, kidney problems, bone pain, and calcium deposits in soft tissues due to elevated blood calcium levels 1. Treatment involves stopping vitamin D supplements, limiting dietary calcium, increasing fluid intake, and possibly using medications like bisphosphonates or corticosteroids in severe cases. To prevent toxicity, adults should generally not exceed 4,000 IU of vitamin D daily unless specifically prescribed by a healthcare provider, and blood levels should be monitored when taking high doses. Some key points to consider when evaluating the effects of vitamin D toxicity include:
- The risk of toxicity is increased with high doses of vitamin D, typically above 10,000 IU daily for months 1
- Vitamin D toxicity can lead to serious health problems, including kidney damage and hypercalcemia
- Treatment of vitamin D toxicity involves stopping vitamin D supplements and managing symptoms
- Prevention of toxicity is key, and adults should be cautious when taking high doses of vitamin D supplements. It's essential to prioritize the single most recent and highest quality study, which in this case is the 2022 ESPEN micronutrient guideline 1, to guide clinical decision-making and ensure the best possible outcomes for patients.
From the Research
Effects of Vitamin D Toxicity
The effects of vitamin D toxicity, also known as hypervitaminosis D, can be severe and include:
- Hypercalcemia, which can lead to acute kidney injury 2, 3, 4, 5
- Nonspecific symptoms such as fatigue, gastrointestinal complaints, confusion, slurred speech, and unstable gait 2, 3
- Elevated serum 25-hydroxyvitamin D levels, which can be indicative of vitamin D intoxication 2, 3, 4
- Normal or high serum phosphorus levels, normal or low levels of alkaline phosphatase (ALP), and low serum parathyroid hormone (PTH) 4
- Hypercalciuria and hyperphosphatemia, which can lead to tissue and organ damage 6
Treatment of Vitamin D Toxicity
Treatment for hypervitaminosis D typically involves:
- Discontinuation of vitamin D intake 2, 3, 4
- A diet with low calcium and phosphorus content 4
- Intravenous hydration with saline, loop diuretics, glucocorticoids, calcitonin, and bisphosphonates 4, 5
- Pamidronate, which can help reduce plasma calcium concentration 5
- Monitoring of serum calcium and vitamin D concentrations, as well as renal function, to ensure that they return to baseline values 2, 3
Causes of Vitamin D Toxicity
Vitamin D toxicity can be caused by:
- Erroneous prescription or administration of vitamin D 2
- Contaminated foods or manufacturing errors of vitamin D-containing supplements 2
- Dispensing errors, resulting in toxic doses of vitamin D being taken 3
- Prolonged and disproportionate consumption of vitamin D supplements, which can lead to vitamin D intoxication even without developing hypervitaminosis D 6