Postpartum Nutrition and Hydration: What Does the Evidence Support?

By Birth & Baby University · Last updated: October 2026 · 4 min read

New parents are bombarded with advice about eating for milk supply, drinking gallons of water and taking supplements. The research is more careful than the advice. This article summarizes what it shows about postpartum nutrition and hydration, what remains unknown and how doulas can nourish families without prescribing.

Key takeaways

• A Cochrane review found only one small, low-quality trial of extra fluids for milk production, and its author reported that advising extra fluids did not improve production. The evidence is too thin to support or refute drinking more.
• A systematic review of 88 studies found strong evidence that DHA and EPA, vitamins A, E and K, iodine and selenium in breast milk respond to maternal intake, and supported DHA and vitamin B12 supplementation for those on restrictive diets.
• Breastfeeding mothers in developed countries generally met reference intakes in a review of 28 articles, though vitamin D intake was below recommendations.
• Iron deficiency anemia is common, can be treated, and screening and treatment decisions belong to clinicians.

What the research says

Fluids

The Cochrane review of extra fluids for breastfeeding mothers identified one small quasi-randomized trial with high risk of bias. Its author reported that advising extra fluids did not improve breast milk production, but milk production was assessed by test weighing, a method not routinely used now, and no data were reported for infant weight gain, duration of breastfeeding or maternal hydration. The reviewers concluded that the evidence is limited. A reasonable reading is that there is no good evidence that forcing fluids increases supply, and no evidence in this review that thirst-driven drinking is harmful.

What lactating mothers eat

A systematic review of 28 articles and an Italian study of 300 mothers found nutrient intakes of breastfeeding mothers in developed countries were generally in line with European reference values, with vitamin D intake below the recommendation, and indicated some nutritional gaps that need advice. Italian mothers’ energy intake averaged about 1,950 kcal per day at six weeks. This describes what mothers eat and not what they should eat, and applies to healthy women in developed countries.

Does diet change milk?

A 2024 systematic review of 88 studies (6,577 participants) found strong evidence that milk levels of DHA, EPA, vitamins A, E and K, iodine and selenium respond to maternal intake, some evidence for several B vitamins, vitamins C and D and others, and insufficient evidence for iron, zinc, copper, choline and arachidonic acid. The review supported DHA and vitamin B12 supplementation for those on restrictive diets, noted high heterogeneity and a need for better trials. It does not show that a particular diet improves milk quantity.

Guidance and iron

A review of the Dietary Guidelines for Americans 2020 to 2025 summarizes healthy patterns emphasizing vegetables, fruits, nuts, legumes, whole grains, lean meat and seafood, dairy and unsaturated oils, with less processed meat, saturated fat and added sugar. A 2022 review on iron deficiency anemia in pregnancy and postpartum describes routine prenatal screening, oral iron as usual first treatment with gastrointestinal side effects that reduce adherence, newer evidence for earlier screening and intravenous iron, and a need for more research on over-supplementation. Blood loss at birth and low iron before pregnancy make postpartum anemia a practical concern, and symptoms such as fatigue, dizziness and breathlessness overlap with other conditions.

What this means for doulas

• Offer food, not rules. Easy, nourishing snacks and meals within reach are supported by the general dietary guidance and are among the most useful things a doula can do.
• Keep fluid advice simple. Encourage drinking to thirst and keeping water nearby. Avoid claims that a specific amount boosts supply.
• Do not recommend supplements or doses. Questions about vitamin D, DHA, B12 or iron belong to the provider or a registered dietitian, especially for restrictive diets.
• Do not diagnose anemia. If a client is pale, dizzy, breathless or extremely tired, encourage contact with their provider, and call urgently for fainting, chest pain or racing heart.

Putting the evidence into practice

• Ask in pregnancy what foods the family likes and which freezer meals, snack supplies and drinks they can stock.
• At visits, notice whether the parent has eaten and has water, and prepare something simple.
• Include cultural and religious postpartum food traditions with respect and curiosity, noting that the evidence reviewed here does not address them.
• Refer to a dietitian for dietary restrictions, gestational diabetes history, eating disorders, or concerns about milk supply that involve nutrition.

The bottom line

The evidence supports ordinary, varied nourishment after birth, and does not support rigid fluid targets or special foods for milk supply. Doulas help most by making eating and drinking easy, and by referring supplement, anemia and dietary questions to qualified clinicians.

This article is for professional education. It is not medical, legal or tax advice. Check the standards of your certifying organization and the rules where you work.

Sources and further reading

• Ndikom CM, et al. Extra fluids for breastfeeding mothers for increasing milk production. Cochrane Database of Systematic Reviews 2014. Read the source
• Di Maso M, et al. Dietary Intake of Breastfeeding Mothers in Developed Countries: A Systematic Review and Results of the MEDIDIET Study. Journal of Nutrition 2021. Read the source
• Falize C, et al. Evaluating the relationship between the nutrient intake of lactating women and their breast milk nutritional profile: a systematic review and narrative synthesis. British Journal of Nutrition 2024. Read the source
• Esquivel MK. Nutrition for Pregnant and Lactating Women: The Latest Recommendations From the Dietary Guidelines for Americans 2020-2025 and Practice Implications. American Journal of Lifestyle Medicine 2021. Read the source
• Elmore C, et al. Screening, Treatment, and Monitoring of Iron Deficiency Anemia in Pregnancy and Postpartum. Journal of Midwifery and Women’s Health 2022. Read the source

Practical support with meals, snacks and recovery routines is a central part of postpartum doula work. See the postpartum doula training and mentorship options on the For Doulas page.

More for professionals: the Professionals Blog.