Can I give my 5 month old water if she is eating solids?

What the evidence says

Health Canada and the Canadian Paediatric Society say babies are usually ready for solid food at about 6 months, though some babies show signs of readiness a little earlier. Once your baby is truly eating solids, it's fine to offer small sips of plain water from an open cup during meals.

Canadian guidance recommends offering water fairly often once solids start, and one Canadian source suggests roughly 125 to 175 mL a day is a reasonable amount at this stage. In the US, the CDC gives a similar range, about 4 to 8 ounces (120 to 240 mL) a day for babies 6 to 12 months old who are eating solids.

The water is meant as a small extra, not a replacement for breast milk or formula, which should still be her main source of nutrition and fluid. Babies' kidneys are still immature, and giving too much plain water can rarely dilute the sodium in their blood, a condition called hyponatremia. This has been reported even in babies as young as five months who were given large amounts of water, causing symptoms like puffiness, seizures, or extreme sleepiness.

So the safe approach is: small sips with meals, from an open cup rather than a bottle, and not as a substitute for milk feeds. If your baby started solids before the usual 6-month mark, it's worth checking with your doctor or public health nurse that this was the right timing for her, since Canadian guidance generally recommends waiting until close to 6 months.

If you notice puffiness, unusual sleepiness, vomiting, or any seizure-like movements after giving water, seek medical care right away, as these can be signs of a rare but serious reaction to too much water.