Nutrition & breastfeeding: Why what you eat matters.

Pregnancy and breastfeeding are particularly demanding times for a woman’s body in terms of nutrition. And not just because it is producing and feeding a growing baby. There are extra demands in terms of stress, lack of sleep, extra household chores, and for many mums, the eventual return to work. While breastmilk concentrations of most nutrients remain relatively stable, if dietary intake is inadequate, it will be at the expense of maternal stores; and in the case of nutrients such as B12 and iodine, baby may be affected as well.

If you’re feeling confused about what to eat while breastfeeding, you’re not alone. There is plenty of information regarding which nutrients are required during lactation, but not a lot on where and how to get them. Most information is drastically skewed toward the health professional, and very little reliable information is available for women who are interested in optimising their nutritional intake while breastfeeding to support their long-term health and that of their baby.


The easy answer is, all of them. But obviously, there are certain micronutrients that are of specific concern. These include iron, calcium, magnesium, vitamin A, vitamin D, B vitamins and iodine. Protein is the major macronutrient that needs attention during lactation, requiring an extra 20g per day on average (1). To put this in perspective, a woman who is exclusively breastfeeding, weighing approximately 70kg, would need to eat the equivalent of 3.5 100g chicken breast fillets daily to meet the RDI for protein.


It’s important to consider the impact of nutritional deficiencies in later life. Consider osteoporosis for example: We know that calcium, magnesium and vitamin D are important for bone health…and yet these are some of the nutrients depleted most quickly whilst breastfeeding. When dietary intake is inadequate, the body can and will begin to break down bone in order to maintain breastmilk concentrations. The same goes for protein. In order to avoid breakdown of lean mass (muscle), a lactating woman must increase her daily intake to meet the demand of the growing infant. Lean mass is directly related to health in later life, so preserving muscle during lactation is worthy of consideration (2).

B group vitamins are particularly important to support maternal energy production, brain health, and recovery following birth. Supplementation is often recommended in the form of prenatal multivitamins which contain optimal dosage of folate, B1, 2, 3, 6 and 12. A word of warning here; it’s best to source a practitioner-only multi, as retail varieties are often of poor quality, poorly absorbed, contain unlisted excipients, and depending on the country of origin, may also contain contaminants. One well known brand in particular contains dangerous amounts of iron, which while useful in iron deficiency, may cause iron overload if dietary intake is adequate. If unsure, please consult your qualified health practitioner.


Many mums are eager to start shedding the kilos as soon as possible, however, it’s important to recognise that a significant amount of weight gain during pregnancy is body fat laid down to support the extra energy requirements necessary for breastfeeding. Losing weight too fast or restricting dietary intake can result in early cessation of breastfeeding and potential nutritional deficiencies. Although eating well with a little one in tow can be challenging, it is certainly possible. Consuming a diet that contains adequate protein, good fats and at least 5 serves of vegetables and 2 serves of fruit a day is ideal. You will also need more fluids – around 2.5-3 litres per day is recommended, although more may be needed when the weather is warm.

Many mums tell me that they know roughly what nutrients they need, but which foods contain what? Here’s a handy list:

Protein – Lean meat, fish, nuts, tofu, eggs, legumes and dairy. Be careful of the last 3 as they may sometimes contribute to wind in your baby, however this is not always the case. Wholegrains are also a source of limited protein.

Calcium – While dairy is usually the automatic choice, it’s not the only one, especially if you or your baby suffer from an allergy or intolerance, or have been recommended to avoid it by your paediatrician. Green vegies (spinach, broccoli, kale) fish with edible bones (like salmon), soy and almonds are also good sources. Almond milk can replace normal milk in your coffee, tea, or on your cereal.

Magnesium – Almonds, cashews, soybeans, barley, leafy green vegies (as above), legumes and wholegrains are good sources. Some women prefer to supplement with a magnesium powder, and as long as it’s safe and recommended for breastfeeding, then that’s perfectly alright too.

Iron – Obviously, the best source is always red meat. But what if you’re vegan or vegetarian? During pregnancy and breastfeeding, I tend to recommend supplementation because low iron levels are no good for either mum or baby. But there are other food sources too, including avocado (nature’s perfect food for motherhood!), almonds, soybeans, wheatgerm and pumpkin seeds.

Vitamin A – Essential for cell differentiation and replication, vitamin A is often overlooked in pregnancy and breastfeeding as it can cause birth defects when taken in high doses. Demands for vitamin A increase significantly during breastfeeding and stores may begin to dwindle if dietary intake is inadequate. The following foods are an excellent source of retinol or i’s precursor beta-carotene: Apricots, carrots, butter, cod liver oil, sweet potatoes and green leafy vegetables.

Vitamin D – The best source of vitamin D is sunshine! Sensible sun exposure generates much more vitamin D than you could possibly supplement at one time – but we all know the dangers of sun exposure. I usually recommend between 5-10 minutes of exposure daily without sunscreen. If unsure, stick with the 5 minute rule. Supplementing during the winter months is always a good idea, as those further south in Australia will struggle to make much vitamin D at all during this time. Speak to your qualified health practitioner to discuss this further.

Iodine – Iodised sea salt, asparagus, oysters, mushrooms and seaweed are all good sources of iodine. Most prenatal multivitamins also contain reasonable amounts. An essential nutrient for gestation and breastfeeding, deficiencies are known to contribute to poor growth and neurodevelopment (3)

B vitamins and folate – Absolutely essential for growth, development, brain health and energy production, the range of foods containing B vitamins is diverse. Green vegetables, legumes, wholegrains, meat, eggs and dairy contain most B vitamins in varying amounts. Folate, which is of particular importance during pregnancy and breastfeeding due to its role in cellular division and DNA replication, can be found in green leafy vegetables, seeds, eggs, legumes and wholegrains.

Good nutrition is important throughout the lifespan, especially during reproduction. A nutrient rich diet helps to replenish maternal nutrient stores and supports long-term wellbeing for both mother and baby.

  2. Abramowitz, M. K., Hall, C. B., Amodu, A., Sharma, D., Androga, L., & Hawkins, M. (2018). Muscle mass, BMI, and mortality among adults in the United States: A population-based cohort study. PLOS ONE13(4), e0194697.
  3. Skeaff S. A. (2011). Iodine deficiency in pregnancy: the effect on neurodevelopment in the child. Nutrients3(2), 265–273. doi:10.3390/nu3020265

Image credit: Image by Public Co from Pixabay


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