Let’s explore breastfeeding nutrition, specifically which nutrients are most critical during the breastfeeding period, why they matter, and what happens if a mother’s diet doesn’t meet these elevated demands.

Pregnancy is often seen as the most nutritionally demanding time in a woman’s life—but breastfeeding is even more nutritionally demanding, and it’s something that women aren’t educated properly on this. During the first six months postpartum, a mother’s body continues to work hard, producing nutrient-rich breast milk to support her baby’s rapid growth and development. This means that nutrient requirements not only stay high—they often increase during breastfeeding.

Why Nutrient Needs Increase After Birth

Breast milk contains everything your baby needs for healthy development in the first six months—protein, fats, vitamins, minerals, immune factors, and more. Careful and considered breastfeeding nutrition is required to maintain the quality of this milk, your body will prioritise the baby’s needs, often drawing on your own nutrient stores if your intake is low.

Producing breast milk requires:

• 500–700 extra calories per day depending on milk volume and baby’s age
• A significant increase in certain vitamins and minerals, sometimes even more than during pregnancy

Key Nutrients Required for Breastfeeding Nutrition (First 6 Months

1. Iodine

• Why it’s needed: Supports baby’s brain development and thyroid function.
• How much: Increases from 220 mcg in pregnancy to 270 mcg during lactation (note: do not supplement with iodine without working with a health practitioner first to assess thyroid function & thyroid antibodies).
• Risks of deficiency: Poor cognitive development in infants; maternal thyroid dysfunction.
• Food sources: Iodized salt, seaweed (in moderation), dairy, eggs.

2. Choline

• Why it’s needed: Crucial for baby’s brain development and memory formation.
• How much: 750 mg/day during breastfeeding.
• Risks of deficiency: Can affect infant cognitive development.
• Food sources: Eggs (especially yolks), liver, beef, chicken, soybeans.

3. Vitamin A

• Why it’s needed: Supports infant vision, immune system, and cellular growth.
• How much: RDA increases to 1500-5000 mcg/day during breastfeeding.
• Risks of deficiency: Increased infection risk and poor vision in infants; maternal depletion.
• Food sources: Liver, sweet potato, carrots, dark leafy greens, eggs.

4. Vitamin B12

• Why it’s needed: Important for neurological development and red blood cell formation.
• How much: 500-1000 mcg/day during breastfeeding.
• Risks of deficiency: Especially concerning in vegan or vegetarian mothers; can lead to irreversible neurological damage in infants.
• Food sources: Meat, eggs, dairy, nutritional yeast (fortified), B12 supplements if needed.

5. Omega-3 Fatty Acids (DHA)

• Why it’s needed: Essential for baby’s brain and eye development.
• How much: 2g Omega-3 fatty acids daily, with 400-600mg DHA
• Risks of deficiency: Lower cognitive outcomes in infants; maternal mood disturbances.
• Food sources: Fatty fish (salmon, sardines), algae oil, flaxseeds, walnuts (less bioavailable).

6. Iron

• Why it’s needed: While breast milk is low in iron, maternal iron status is still important for birth recovery and energy.
• How much: depends on your current iron stores
• Risks of deficiency: Maternal fatigue, poor immune function; affects future pregnancies.
• Food sources: Red meat, legumes, leafy greens, liver, pumpkin seeds.

7. Calcium

• Why it’s needed: Breast milk contains calcium regardless of dietary intake, if intake is insufficient you will draw calcium from your bones, which can affect bone density long-term.
• How much: 1200mg/day from diet and supplement sources
• Risks of deficiency: If intake is low, calcium is drawn from maternal bones, potentially reducing bone density.
• Food sources: Dairy, sardines with bones, tahini, tofu, almonds, leafy greens.

7. Vitamin D

• Why it’s needed: Breast milk vitamin D content reflects maternal vitamin D stores, and is crucial for regulating calcium status in the body (bone density and mineralisation) immune and general health.
• How much: RDI of 400 IU daily for breastfed infants, preferably from maternal intake
• Risks of deficiency: If intake is low, calcium is drawn from maternal bones, potentially reducing bone density.
• Food sources: Dairy, sardines with bones, tahini, tofu, almonds, leafy greens.

What Happens If Intake is Insufficient?

When a breastfeeding mother doesn’t meet her nutritional needs, the body will still prioritise milk quality—but at a cost to her own health:

• Bone density loss (calcium)
• Cognitive strain or fatigue (B12, iron, DHA)
• Thyroid dysfunction and increased antibodies postpartum (iodine)
• Mood changes, anxiety, or depression (omega-3s, B vitamins)
• Depleted stores for future pregnancies

In the long term, this can lead to nutrient depletion and a greater risk of health issues for the mother—especially if she has multiple pregnancies close together without time to replete her stores.

Final Thoughts

Supporting new mothers nutritionally doesn’t end at birth. In fact, the postpartum period is one of the most critical windows for replenishing nutrients, maintaining energy, and ensuring both mother and baby thrive.

If you’re breastfeeding—or planning to—it’s worth checking work with a Naturopath to assess your diet and supplement routine. Eating well and supporting your stores now sets the foundation for long-term vitality, both for you and your baby. You can read more about my services here.