For individuals taking vitamin D without a prescription:
Vitamin D is stored in the body; therefore, when you take more than the body needs, it will build up in the body. This may lead to poisoning. Problems are more likely to occur in:
Adults taking 20,000 to 80,000 Units a day and more for several weeks or months.
Children taking 2,000 to 4,000 Units a day for several months.
If you are taking this medicine for a reason other than as a dietary supplement, your doctor should check your progress at regular visits to make sure that it does not cause unwanted effects.
Do not take any nonprescription (over-the-counter [OTC]) medicine or dietary supplement that contains calcium, phosphorus, or vitamin D while you are taking any of these dietary supplements unless you have been told to do so by your health care professional. The extra calcium, phosphorus, or vitamin D may increase the chance of side effects.
Do not take antacids or other medicines containing magnesium while you are taking any of these medicines. Taking these medicines together may cause unwanted effects.