Nourishing Mom During the Fourth Trimester: Part III

By Whitney Crouch, RDN, CLT

While running around being a “stay-at-home” mom, a “9-5” mom, or somewhere in between, it can be easy for mothers to forget about taking care of themselves. Breastfeeding mothers may face an added layer of stress when trying to do it all and be everything to everyone, but keeping nourished should be a top priority.

In the previous parts of this series, we examined mothers’ challenges with producing adequate milk supply for their babies, as well as nutrition and supplements to support her supply.

Motherhood and liquid gold

Proper diet and hydration are often sacrificed when juggling the demands of a new baby, housework, career, other children, and any semblance of a social life. This altruistic sacrifice could unknowingly lead to negative consequences.

Milk Production 101

While the need for nutrient-dense foods will always ring true, the number of calories required to allow healing and support adequate milk production varies from woman to woman.

Calorie needs for breastfeeding moms depend on how much energy mom is exerting daily, plus how much milk she is producing. On average, an exclusively breastfeeding mother needs about 500-640 calories more per day than she did prepregnancy.1,2

The average baby consumes 19-30 ounces of milk per day, but mother’s hydration needs actually exceed the amount of milk produced and her prenursing hydration needs combined.3 According to the Dietary Reference Intakes (DRIs), mom needs around an extra 34 ounces (1 liter) of water each day, and if she still feels thirsty, she should drink more water.4

Fueling the nurturer

It’s common for new moms to fall into the habit of always putting baby first. Of course, it’s important to keep baby out of harm’s way, but when baby’s needs are met, it’s okay to put baby down (or wear baby in carrier) so that mom can put on her own proverbial oxygen mask.

The act of growing a baby and then giving birth is a tremendous stressor on a woman’s body. Albeit a completely natural, beautiful, and often relished stressor, a women’s body needs rest and nutrient-dense foods to heal properly and to continue to give life to her baby.

Across various traditional cultures, there are heavy emphases on postpartum nutrition. While the dishes for postpartum nutrition vary by culture, there are many commonalities, with animal products, cooked vegetables, herbs, and spices as mainstays in most cultures.5

Eating to heal

At a glance, traditional healing foods reveal that broths, soups, stews, and porridge are central to a new mother’s diet.6

Slow-cooked stews and broths are rich in collagen-building amino acids such as glycine and proline, electrolytes, and “warming” spices and herbs.5 Porridge-like foods and cooked vegetables provide fiber-rich carbohydrates.

It’s no coincidence that these nutrient-dense foods are easy to digest and rich in iron, B vitamins, zinc, choline, DHA, protein, carbohydrates, and a number of other nutrients that support replenishing red blood cells, tissue healing, and the production of high-quality breastmilk.5

In addition to eating wholesome foods, new mothers should not reduce calories or carbohydrates in the months immediately following giving birth.7-9 If weight loss is desired once her breastmilk supply is established, mom can mindfully reduce carbohydrate intake while monitoring her milk supply and ensure her diet remains otherwise nutrient-dense.5

Nourishing baby

Like adult food, human milk is made up of carbohydrates, fat, protein, vitamins, and minerals, plus the addition of nonnutritive bioactives. Some of the milk components remain at consistent levels across the breastfeeding relationship, while others vary from mother to mother and for each mother across time.10 Each mother’s milk is unique based on her dietary intake, body stores, time frames (time of day, season, circadian rhythms), time intervals (time of day, time since previous breast emptying and duration of feed), and time relative to maternal exposures (e.g., meals, pathogens, and supplements).10,11 Let’s explore these nutrients a little further…


Breastmilk fat quantity is mainly dependent on the feeding period, the stage of the feed, and the number of pregnancies mom has had, while maternal diet (energy intake, amount of dietary fat) and lifestyle are less relevant (except in cases of severe malnutrition).12

Fat is made up of subunits called fatty acids; the fatty acid profile of breastmilk is reliant upon both mom’s current diet and her dietary intake during the pregnancy.13 Interestingly, much of the fat in early breastmilk comes from mom’s longer-term food intake, mainly during the third trimester of pregnancy.13 And while the amount of fat in breastmilk is not directly related to diet, the composition of the fatty acids in the breastmilk is related to diet.13

Important to fetal and infant brain and vision development, eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) are two omega-3 fatty acids that may be lacking in mom’s diet. If she consumes a standard American diet (SAD) or a vegan diet, which are inherently lacking in fatty fish intake, baby is at an especially high risk of deficiency.14 Even though the human body holds the necessary enzymatic pathway to make DHA from its plant-based precursor alpha-linolenic acid (ALA), there is clear evidence that the conversion of ALA to EPA and DHA is insufficient to ensure adequate levels in baby.17 In fact, it has been shown that the efficiency of the conversion of ALA to EPA is lower than 10%; the conversion of ALA to DHA is even lower, and virtually nonexistent in boys and men.15

Pregnant and lactating women should aim to consume an average dietary intake of at least 200 mg DHA/d.16

In order to balance adequate amounts of EPA and DHA with lowered risk of environmental contaminants, more small fish (e.g., sardines, anchovies and mackerel) should be eaten over larger fish, and wild-caught or safely farmed salmon should also be preferred. Fortunately, nature has included selenium in fatty fish, which counteracts methylmercury toxicity in humans and protects against some neurological effects of mercury exposure.17 This is an important fact to note in light of weighing the risks to benefits of increased seafood intake with increasing exposure to harmful methylmercury, polychlorinated biphenyls (PCBs), and dioxins found in some seafood.18

Supplementation with DHA and EPA that has been third party-tested for contaminants (e.g. heavy metals, dioxins, etc.) can be a convenient way for mothers to ensure adequate omega-3 fatty acid intake.


Like fats, the protein composition of human milk is more affected by mother’s intake than the actual amount of protein in the milk or by maternal or gestational age.10

While the concentration of protein in the milk is not affected by mom’s diet, it does increase with maternal body weight for height and decreases in mothers producing higher amounts of milk.19 In addition, while the makeup of breastmilk shows a consistent level of protein regardless of time of day, although protein concentration does decrease through each lactation session.20


The predominant carbohydrate in breastmilk is lactose; however, there are also nondigestible, nonnutritive carbohydrates. These nondigestible carbohydrates, called oligosaccharides, act as food for the beneficial gut bacteria that bloom into baby’s gut microbiome.10

Lactose concentrations are lowest in colostrum and increase through the first 4 months of lactation.21 Unlike the other macronutrients, lactose concentrations are fairly consistent across the milk of different mothers and are not influenced by maternal weight or number of pregnancies.10

Vitamins and minerals

As mentioned earlier, some nutrients depend on mom’s current dietary intake, while others rely on her bodily stores.10

The following nutrients change with mother’s intake, adequacy or deficiency, and/or supplementation. Real food sources follow each nutrient:11,23

  • Vitamin B1 (thiamine): legumes (e.g., beans and lentils), nuts, lean pork, and yeast
  • Vitamin B2 (riboflavin): milk (stored in opaque bottle), egg, spinach, almond, chicken, beef
  • Vitamin B6 (pyridoxine): wild-caught salmon, turkey, chicken, avocado, russet potato, spinach, banana
  • Vitamin B12 (cobalamin): clams, mussels, crab, beef, salmon, milk, turkey, poached egg
  • Choline: beef liver, wheat germ, eggs, beef, scallop, salmon, cod, shrimp, chicken, Brussels sprouts, broccoli, peanuts
  • Vitamin D (cholecalciferol): pink salmon, sardines, egg yolk
  • Vitamin A (as retinol): beef liver, cod liver oil, egg, butter, whole milk
  • Vitamin C (ascorbic acid): kiwi, citrus fruit, strawberries, bell peppers, Brussels sprouts, potato, tomato
  • Vitamin E (tocopherol): vegetable oils, nuts, tomatoes, avocados, rainbow trout, leafy greens, blackberries
  • Vitamin K (phylloquinone, menaquinone): green leafy vegetables, parsley, watercress (K1); cheese curds, natto (K2)
  • Iodine:  cod, milk, potato with peel, turkey breast, navy beans, iodized salt
  • Calcium: plain yogurt, sardines, cheddar cheese, milk, Chinese cabbage, figs, orange, kale, broccoli, beans
  • Selenium: organ meats, seafood, Brazil nuts, pork, beef, chicken

It’s important to note that it’s difficult to consume adequate vitamin D through food alone. Known as the “sunshine vitamin,” vitamin D is mostly obtained through unprotected skin’s exposure to ultraviolet (UV) light, but in geographic areas with poor seasonal UV exposure or in individuals who spend a lot of time indoors, supplementation may be necessary. Fortunately, a new randomized controlled trial found that for deficient mothers, supplementing with 6,000 IU of vitamin D3 safely optimizes maternal vitamin D status and improves milk vitamin D to maintain adequate infant serum vitamin D levels.24 Vitamin D levels should be monitored by a healthcare practitioner.

Final thoughts…

Breastmilk conveys immeasurable benefits, even if some of the nutrients are lacking at times, and is therefore baby’s preferred food.24 That said, fed is always best.


1. Institute of Medicine (US) Committee on Nutritional Status During Pregnancy and Lactation. Nutrition During Lactation. Washington (DC): National Academies Press (US); 1991. 9, Meeting Maternal Nutrient Needs During Lactation.
2. Kominiarek MA et al. Nutrition recommendations in pregnancy and lactation. Med Clin North Am. 2016;100(6):1199–1215.
3. Dewey KG et al. Milk and nutrient intake of breast-fed infants from 1 to 6 months: relation to growth and fatness. J Pediatr Gastroenterol Nutr. 1983;2(3):497-506.
4. “‘Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate’ at” National Academies Press: OpenBook, 2005,
5. Nichols L. Real Food for Pregnancy. United States;2018:222-238.
6. Raman S et al. Eating soup with nails of pig: thematic synthesis of the qualitative literature on cultural practices and beliefs influencing perinatal nutrition in low and middle income countries. BMC Pregnancy Childbirth. 2016;16(1):192.
7. Sloan G et al. A rare cause of metabolic acidosis: ketoacidosis in a non-diabetic lactating woman. Endocrinol Diabetes Metab Case Rep. 2017;2017. pii: 17-0073.
8. Al Alawi AM  et al. Lactation ketoacidosis: case presentation and literature review. BMJ Case Rep. 2018;2018. pii: bcr-2017-223494.
9. Gleeson S et al. Lactation ketoacidosis: an unusual entity and a review of the literature. Perm J. 2016;20(2):71–73.
10. Dror DK  et al. Overview of Nutrients in Human Milk. Adv Nutr. 2018;9(suppl_1):278S-294S.
11. Casavale KO et al. NIH workshop on human milk composition: summary and visions. Am J Clin Nutr. 2019. pii: nqz123. doi: 10.1093/ajcn/nqz123. [Epub ahead of print]
12. Sauerwald TU et al. Polyunsaturated fatty acid supply with human milk. Lipids. 2001;36(9):991-996.
13. Mennitti LV et al. Type of fatty acids in maternal diets during pregnancy and/or lactation and metabolic consequences of the offspring. J Nutr Biochem. 2015;26:99–111.
14. Bzikowska-Jura A et al. The concentration of omega-3 fatty acids in human milk is related to their habitual but not current intake. Nutrients. 2019;11(7):1585.
15. Marangoni F et al. Maternal diet and nutrient requirements in pregnancy and breastfeeding. An Italian consensus document. Nutrients. 2016;8(10):629.
16. Koletzko B et al. Perinatal Lipid Intake Working Group; Child Health Foundation; Diabetic Pregnancy Study Group; European Association of Perinatal Medicine; European Association of Perinatal Medicine; European Society for Clinical Nutrition and Metabolism; European Society for Paediatric Gastroenterology, Hepatology and Nutrition, Committee on Nutrition; International Federation of Placenta Associations; International Society for the Study of Fatty Acids and Lipids.  Dietary fat intakes for pregnant and lactating women. Br J Nutr. 2007;98(5):873-877.
17. Mania M et al. [Fish and seafood as a source of human exposure to methylmercury]. Rocz Panstw Zakl Hig. 2012;63(3):257-264.
18. Mozaffarian D  et al. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA. 2006;296(15):1885-1899.
19. Nommsen LA et al. Determinants of energy, protein, lipid, and lactose concentrations in human milk during the first 12 mo of lactation: the DARLING Study. Am J Clin Nutr. 1991;53(2):457-465.
20. Hollanders JJ et al. The association between breastmilk glucocorticoid concentrations and macronutrient contents throughout the day. Nutrients. 2019;11(2):259.
21. Coppa GV et al. Changes in carbohydrate composition in human milk over 4 months of lactation. Pediatrics. 1993;91(3):637-641.
22. Micronutrient Information Center. Linus Pauling Institute. Published 2019. Accessed August 28, 2019.
23. Dawodu A et al. The effect of high-dose postpartum maternal vitamin D supplementation alone compared with maternal plus infant vitamin D supplementation in breastfeeding infants in a high-risk population. A randomized controlled trial. Nutrients. 2019;11(7). pii: E1632.
24. Zhu J et al. The Functional Power of the Human Milk Proteome. Nutrients. 2019;11(8). pii: E1834.

Whitney Crouch, RDN, CLT
Whitney Crouch is a Registered Dietitian who received her undergraduate degree in Clinical Nutrition from the University of California, Davis. She has over 10 years of experience across multiple areas of dietetics, specializing in integrative and functional nutrition, specifically autoimmune Hashimoto thyroiditis. When she’s not creating educational programs or writing about nutrition, she’s spending time with her husband and two young children. She’s often found running around the bay near her home with the family’s dog, or in the kitchen cooking up new ideas.

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