Can this be combined with a multivitamin or other supplements the child already takes?

The main thing to check is whether the child's other products already contain vitamin C. Many children's multivitamins, fortified drinks, effervescent products and even some fortified foods include ascorbic acid, so combining several of them can add up to more than intended without anyone noticing. Read the labels of everything the child takes regularly and add up the vitamin C amounts before introducing another source.

One combination that is genuinely logical rather than problematic: vitamin C helps the body use iron from food more effectively, so if a child's meals include plant-based iron sources, taking the tablet with such a meal works in the same direction.

A few practical rules for any combination of children's supplements:

• Stick to the age-appropriate directions on each package — do not double up on the same nutrient from two products "just in case".
• Introduce one new product at a time, so if the child reacts to something (for example, an upset stomach), you know which product it was.
• Store all tablets out of children's reach; flavoured tablets in particular can look like sweets to a small child.

If the child has dietary restrictions, a chronic condition or takes medication, consult a doctor or pharmacist before combining supplements — that single check answers the question far more reliably than label-reading alone.