Developing Lactose Intolerance

What is lactose intolerance?

If your child is lactose intolerant, it means that their body cannot make enough of the enzyme lactase to digest lactose, the sugar found in milk and milk products. Lactose then stays in their digestive system and causes problems. Although this can be uncomfortable, it isn’t dangerous.1

Types of lactose intolerance2

  1. Primary lactose intolerance is the most common, usually developing later in childhood or in adulthood as the body starts producing less lactase. It is extremely rare in babies because milk is the natural first food for all humans so our bodies are born ready for it.
  2. Secondary lactose intolerance is generally due to an illness or injury to the small intestine and can be temporary if the underlying cause is treated.
  3. Congenital lactose intolerance is a very rare genetic condition, passed down from a baby’s parents. It requires medical intervention as the baby cannot tolerate breast milk.
  4. Developmental lactose intolerance occurs if a baby is born prematurely and their lactase production hasn’t fully developed.

Lactose intolerance vs cows’ milk allergy

Lactose intolerance and cow’s milk allergy are quite different, although many confuse the two. Read more about the difference between allergies and intolerances here.

What are the symptoms of lactose intolerance1,2?

  • Stomach pain and bloating
  • Diarrhoea
  • Nausea
  • Excessive wind
  • Irritable behaviour and restless sleep
  • Nappy rash

Symptoms can start 30 minutes to 2 hours after drinking dairy-based formula or eating dairy foods. Symptoms generally occur when your child has reached their tolerance limit to lactose.

Lactose intolerance is very uncommon in babies however if you are concerned it would be useful to record your child’s symptoms and note any new foods or changes to their diet and take these to your doctor for advice.

How is lactose intolerance managed?

The amount of lactose that can be tolerated can vary and may only be temporary (secondary lactose intolerance).

  • Continue breastfeeding or seek medical advice before changing formula for a formula-fed baby.2
  • Keep a food diary for your baby and record any symptoms – this will help to identify their tolerance levels and problem foods.
  • Get to know lactose levels – some dairy foods contain more lactose than others. For example, your baby may be able to tolerate a little hard cheese or yoghurt without symptoms, but not cope with cows’ milk or formula on cereal or in milk pudding.1,2
  • Try not to avoid dairy completely – it is a key food group, providing a good source of calcium for growing bones and teeth. If your child’s tolerance level is very low, make sure you replace dairy foods with other calcium rich options.
  • Get help – A dietitian or a paediatrician can be a great source of information, and can provide plenty of tips, tricks and resources. Making living with lactose intolerance a little easier for the whole family.

This section is for your information only and is not intended to take the place of medical advice. See your doctor or another healthcare professional for advice specific to your baby.