The availability of numerous vitamin D3-containing products, which differ considerably in strength, pharmaceutical form, indications and dosage regimens, including within the same product range, constitutes a potential source of medication errors.
There are many medicines and dietary supplements containing vitamin D3. Highly concentrated preparations may lead to toxicity in the event of dosing errors.
The FAMHP reminds the public that it is essential to follow the dosage recommendations for vitamin D3-based medicines, particularly if the proprietary medicinal product is high-dose. Infants, children and the elderly are groups at particular risk of overdose.
The presence of liquid forms (drops) in different strengths requires particular attention. These are widely used in paediatrics, and the number of drops to be administered varies depending on the concentration of the solution. It is therefore important to remind patients of the dosage (number of drops to be administered daily) when prescribing and dispensing these medicines, and to raise awareness of the risk of overdose.
An overdose may cause hypervitaminosis, hypercalcaemia and hyperphosphataemia. Signs and symptoms of overdose may include weight loss, loss of appetite, fatigue, vomiting, constipation, headache, thirst, drowsiness, dizziness, kidney stone formation and cardiac arrhythmias. In extreme cases, hypercalcaemia can lead to a coma or even death.
The dosage should be determined individually according to the medicinal product used and the indication for treatment.
The indications and dosages for medicines are set out in sections 4.1 and 4.2 of the summaries of product characteristics and in sections 1 and 3 of the patient information leaflets. These documents are available on the FAMHP website.
Vitamin D3-containing medicinal products authorised in Belgium
Situation as at 15 September 2026
Examples of situations where errors are likely to occur
- Confusion between the different strengths, particularly within the same product range.
- Error in the frequency of administration.
- Difficulty administering a precise number of drops directly into the mouth. Administering the drops onto a spoon can facilitate accurate counting and administration.
- Unintentional simultaneous intake of several medicines and/or food supplements containing vitamin D.
- Substitution of one proprietary medicinal product for another without adjusting the dosage.
In case of overdose, call a doctor or the poison control centre on 070 245 245.
Report medication errors
You can notify the FAMHP of actual or potential medication errors, with or without adverse effects. The FAMHP will assess the causes of the error and, where possible, identify measures to prevent recurrence.
Excerpt from the official page. The original is authoritative.