From the Guidelines
Vitamin D toxicity, also known as hypervitaminosis D, occurs when excessive amounts of vitamin D build up in the body, typically from supplement overuse rather than sun exposure or diet, and can lead to symptoms such as nausea, vomiting, weakness, frequent urination, kidney problems, bone pain, and confusion. The primary mechanism involves elevated calcium levels in the blood (hypercalcemia), as vitamin D enhances calcium absorption, and severe cases may lead to kidney stones, kidney failure, abnormal heart rhythms, and even death, as noted in studies such as 1.
Symptoms of Vitamin D Toxicity
- Nausea and vomiting
- Weakness
- Frequent urination
- Kidney problems
- Bone pain
- Confusion Toxicity usually results from taking more than 10,000 IU daily for extended periods, far exceeding the recommended daily allowance of 600-800 IU for most adults, as discussed in 1.
Treatment of Vitamin D Toxicity
Treatment involves stopping vitamin D supplements, limiting dietary calcium, increasing fluid intake, and in severe cases, medications like corticosteroids or bisphosphonates, as mentioned in 1. If you experience these symptoms and take high-dose vitamin D supplements, seek medical attention promptly for proper diagnosis and treatment, as emphasized in 1. It is essential to note that the 25-(OH)D level associated with toxicity (often defined as >500 nmol/L [>200 ng/mL]) is well above the level considered to be sufficient, as stated in 1. Therefore, it is crucial to be aware of the potential risks of vitamin D toxicity and to monitor vitamin D levels regularly, especially when taking high-dose supplements, to prevent adverse outcomes, as highlighted in 1.
From the Research
Symptoms of Vitamin D Toxicity
The symptoms of Vitamin D toxicity, also known as hypervitaminosis D, can vary but often include:
- Nonspecific symptoms such as fatigue and gastrointestinal complaints 2
- Hypercalcemia, which can lead to acute kidney injury 2, 3
- Pancreatitis 3, 4
- Nausea and vomiting 4
- Altered sensorium 4
- Constipation 4
- Weight loss 4
- Hypercalciuria and hyperphosphatemia, which are considered initial signs of vitamin D intoxication 5
Biochemical Features
Biochemical features of vitamin D toxicity include:
- Elevated 25-hydroxyvitamin D levels 2, 3, 6, 4
- Hypercalcemia, with total calcium levels ranging from 11.1 to 15.7 mg/dl 3, 4
- Acute kidney injury, with elevated creatinine levels 2, 3
- Changes in intact parathyroid hormone levels 4
Risk Factors
Risk factors for vitamin D toxicity include:
- Overdose of vitamin D caused by prescription of mega-doses of vitamin D 4
- Excessive consumption of vitamin D supplements, even without developing hypervitaminosis D 5
- Manufacturing errors of vitamin D-containing supplements 2
- Contaminated foods or manufacturing errors of vitamin D-containing supplements 2