From the Guidelines
Vitamin D acute toxicity in pediatrics is rare and usually results from doses much higher than 10,000 IU/day, with serum concentrations >375 nmol/L associated with acute hypercalcaemia and hyperphosphataemia. The main function of vitamin D is the regulation of calcium and phosphate, essential for bone health 1. According to the ESPGHAN Committee on Nutrition, a well-defined threshold for vitamin D acute toxicity has not been established, but prolonged daily intake up to 10,000 IU or up to serum concentrations of 25(OH)D of 240 nmol/L appears to be safe 1.
Key Recommendations
- The ESPGHAN Committee on Nutrition recommends a total daily vitamin D intake of 400 IU/day for infants and 600 IU/day for children and adolescents 1.
- Tolerable upper intake levels identified by the IOM are 1000 IU/day for infants ages 0-6 months, 1500 IU/day for infants ages 7-12 months, 2500 IU/day for children ages 1-3 years, 3000 IU/day for children ages 4-8 years, and 4000 IU/day for children and adolescents ages 9-18 years 1.
- Prevention of vitamin D toxicity is crucial by adhering to recommended daily allowances and monitoring serum 25(OH) vitamin D concentrations, with levels > 50 nmol/L indicating sufficiency 1.
Treatment and Prevention
- Treatment of vitamin D acute toxicity involves immediate discontinuation of vitamin D supplements, limiting dietary calcium, increasing fluid intake, and in severe cases, administering intravenous fluids and loop diuretics 1.
- Prevention is key, and parents should be educated on the risks of excessive vitamin D supplementation, with a focus on adhering to recommended daily allowances and monitoring serum levels.
From the Research
Definition and Diagnosis of Vitamin D Acute Toxicity
- Vitamin D toxicity (VDT) is defined as serum 25(OH)D levels exceeding 100 ng/mL (250 nmol/L) or hypervitaminosis D 2.
- VDT can be diagnosed by serum 25-hydroxyvitamin D [25(OH)D] concentrations higher than 150 ng/ml (375 nmol/l) 3.
- Hypercalcemia is a common condition of vitamin D toxicity, which can be induced by vitamin D and its metabolites in moderate levels 2.
Symptoms and Findings of Vitamin D Intoxication
- Symptoms of VDT include confusion, apathy, recurrent vomiting, abdominal pain, polyuria, polydipsia, and dehydration 3.
- Findings associated with VDI are closely related to serum calcium concentration and duration of hypercalcemia, including hypercalcemia, normal or high serum phosphorus levels, normal or low levels of alkaline phosphatase (ALP), high levels of serum 25OHD, low serum parathyroid hormone (PTH), and high urine calcium/creatinine 4.
Treatment and Management of Vitamin D Toxicity
- The main goal of treatment for VDI is correction of the hypercalcemia 4.
- Treatment for VDI includes discontinuation of intake, a diet with low calcium and phosphorus content, intravenous hydration with saline, loop diuretics, glucocorticoids, calcitonin, and bisphosphonates 4, 2.
- In cases of severe hypercalcemia, emergency intervention is necessary due to the adverse effects of hypercalcemia on cardiac, central nervous system, renal, and gastrointestinal functions 4.
Prevention and Public Awareness
- Increased public awareness of vitamin D-related health benefits might increase the risk of VDT due to self-administration of vitamin D in doses higher than recommended for age and body weight or even higher than the established upper limit intake values 3.
- Parents should be cautious when providing vitamin D to their children, and healthcare providers should monitor vitamin D levels in infants and children who receive long-term vitamin D supplementation at or above the upper level intake that is currently recommended 5, 2.