Baby nutrition and immune systems

Breastfeeding gives your baby the best start in life and offers many benefits, including supporting your immune system development^3,4.
Read more about the natural brilliance of breastmilk.

For their first 12 months, breastmilk or formula milk will provide most of the nutrients your baby will need for growth⁵ including carbohydrates, fat and protein as well as compounds that will benefit your child’s immune system, such as vitamins, minerals and prebiotics⁶.

From 6 months, nutrient-rich foods can be incorporated into your baby’s diet and these play a key role in topping up essential vitamins and minerals as well as helping to strengthen your baby’s own defences⁷.

Read more to learn which nutrients are important to include in your baby’s weaning diet and which foods are the best sources.

It's no accident that your baby’s hunger for solid foods coincides with their ability to sit up and enjoy a more independent view of the world. During the weaning stage, your baby becomes stronger, learns new ways to express their wants and needs, and continues to grow at a rapid rate^8.

Weaning foods not only top up some essential nutrients for your baby but also help them to explore different tastes and textures, learn to chew, and strengthen the muscles that are important for speech while developing healthy habits from early on ^9,10,11,12.

Providing a variety of wholesome, nutritious weaning foods will fuel your baby’s learning and development into toddlerhood and support their health throughout life₁₂.

Certain foods are easy to mash or purée when raw: bananas, avocados and mango are nutrient-rich examples. Others need to be cooked before puréeing, and the best ways to prepare them to preserve their vitamin content varies between vegetables, for example steaming is best for broccoli¹³. Offering a rainbow of colours will help to ensure your baby receives a wide range of vitamins and minerals¹⁴. Read more about making baby food.

Vitamin D plays a part in the normal functioning of your child’s immune system, which is your child´s defence against infections. It is also needed to aid the absorption of calcium and phosphorus, two minerals that help to form the strong healthy bones and teeth that will support your baby throughout life^15.

Food sources of vitamin D are limited and include¹⁶:

• Oily fish – herring, salmon, sardines and mackerel
• Eggs
• Fortified fat spreads
• Fortified breakfast cereals

It is difficult to get the recommended intake of vitamin D from foods alone. Because of this, the Department of Health advises a daily vitamin D supplement of 8.5-10 micrograms (0.0085-0.01mg) for all babies up to one year, and 10 micrograms (0.01mg) for all children ages one to four years¹⁷.

Formula-fed babies don’t need vitamin D supplements until they are drinking less than 500ml of formula per day, usually at around 12 months old, because most infant milks are fortified with vitamin D¹⁷.

Iron, a mineral found in high levels in meats, beans, dried fruits and fortified breakfast cereals, supports your baby’s physical and mental development. This early development lays the foundations for all development yet to come, which is why iron is such an important nutrient to include in your baby’s weaning diet¹⁸.

Too little iron can lead to iron deficiency anaemia – a condition that can affect your baby’s immune response. Premature babies may be at increased risk of this due to missing out on iron stores that normally build up during the later stages of pregnancy^19,20.

Iron comes in two forms. Haem-iron is found in meat and fish and is easily absorbed by the body. Non-haem iron is present in plant foods and is harder for the body to absorb and use. Even small amounts of meat and fish in your baby’s diet can help them to absorb the iron from other food sources²¹.

Include the following iron-rich foods in your baby’s weaning diet to increase their intake²¹:

• Meats and oily fish, such as sardines and salmon
• Dark green, leafy vegetables such as kale and spinach
• Beans and other pulses
• Dried fruit
• Fortified breakfast cereals

Vitamin C aids the absorption of iron from foods, particularly from plant sources, so when you can, include them in the same meal²². Beneficial combinations include beef stew with tomatoes and peppers; fortified porridge with lightly stewed berry fruits; bean and potato mash with sticks of steamed broccoli or carrots as finger foods; and sardines in tomato sauce.

Zinc²³ is a mineral found in all cells throughout the body. It helps the immune system to fight off invading bacteria and viruses by creating new cells and enzymes. It also plays role in healing scratches and wounds.

As with iron, once your baby reaches a certain age, they need complementary foods with zinc to meet their increased needs, so it is important to include good sources from the start of weaning.

Good sources of zinc to increase your baby’s intake include:

• Meat
• Milk and cheese
• Bread
• Cereal products

Calcium is needed for the healthy development of your baby’s bones and teeth. This important nutrient helps to build your baby’s skeleton as they grow²⁴.

Most of your baby’s calcium intake comes from milk, whether they’re breastfeeding or formula feeding. Cows’ milk also contains calcium but isn’t suitable as a main drink for babies under 12 months old²⁵.

Other sources of calcium include²⁴:

• Milk, cheese and other dairy foods
• Green, leafy vegetables, such as broccoli, cabbage and okra, but not spinach
• Soya beans and tofu
• Nuts – can be introduced if finely ground
• Bread and anything made with fortified flour
• Oily types of fish where you eat the bones, such as sardines and pilchards (check for any larger pieces of bones)

Potassium is involved in controlling the balance of fluids in the body and is important in bone and heart health²⁶. Selenium has important antioxidant properties and plays a role in supporting the immune system²⁷.

Potassium is found in most types of food. Good sources of potassium that are suitable for your baby include²⁶:

• Fruit and vegetables
• Beans and pulses
• Nuts, if finely ground
• Milk
• Meat and fish
• Bread

Good sources of selenium include²⁸:

• Brazil nuts, if finely ground
• Meat and fish
• Eggs

One of the B-group of vitamins, B12²⁹ supports development of your baby’s nervous system and it is important that they have a reliable, steady supply. It is also involved in making red blood cells as your baby grows, as well as releasing energy from food.

Good sources of this nutrient for your baby include:

• Meat
• Salmon and cod
• Milk and cheese
• Eggs
• Some fortified cereals – check the labels to make sure they have been fortified

Omega 3 is a type of long chain polyunsaturated fatty acid (LCP) that contributes to the development of your baby’s brain as well as their normal visual development ³¹.

Oily fish, such as sardines, pilchards or salmon, are an excellent source of Omega 3 and can be offered as part of your baby’s weaning diet once or twice each week.  

In terms of foods, non-fish sources of Omega 3 fats are thought to be less effective compared to fish, but they still have some benefit. These include:

• Fortified eggs
• Fortified fat spreads
• Fortified breads
• Linseed, walnut and rapeseed oils