The dose that can cause toxic effects depends on individual sensitivity. Symptoms of overdose in adults can occur when administered at doses of 20,000 to 60,000 ME or more per day for several weeks or months, and in children - when applied at doses from 2000 to 4000 ME for several months, and also after a single application of a high dose of the drug.
Symptoms of hypervitaminosis D3: early (due to hypercalcemia) - constipation or diarrhea, dryness of the oral mucosa, headache, thirst, pollakiuria, nocturia, polyuria, anorexia, metallic taste in the mouth, nausea, vomiting, fatigue, general weakness, adynamia, dehydration, hypercalcemia, hypercalciuria, an increase in plasma concentrations of 25-dihydrocolecalciferol; late pain in the bones, clouding of urine (the appearance of hyaline cylinders, proteinuria, leukocyturia in the urine), increased blood pressure, pruritus, photosensitivity of the eyes, congestion hyperemia, arrhythmia, drowsiness, myalgia, nausea, vomiting, pancreatitis, gastralgia, weight loss; rarely - changes in the psyche (up to the development of psychosis) and mood.
Symptoms of Chronic Overdose of Vitamin D3: calcification of soft tissues, kidneys, lungs, blood vessels, increased blood pressure, renal and heart failure (these effects occur most often with adherence to hypercalcemia, hyperphosphataemia), growth disorders in children (prolonged intake at a dose of 1800 IU / day).
Treatment: in acute or chronic overdose it is necessary to carry out measures for the treatment of developing hypercalcemia. Depending on the degree of severity of hypercalcemia, the following measures are used: drug cancellation, low calcium diet, consumption of large amounts of liquid, use of glucocorticosteroids, vitamin E, ascorbic acid, retinol, thiamine, pantothenic acid, riboflavin; in severe cases - intravenous injection of 0.9% solution of sodium chloride, furosemide, electrolytes, hemodialysis, the introduction of calcitonin. There is no specific antidote.
To avoid overdose with the use of the drug is recommended to monitor the calcium content in the blood plasma.