Nutrition During Breastfeeding - Which nutrients are dependent on your diet and which aren’t?
Co-written by Megan Churchill, Dietetics Student
Let’s talk about breastfeeding!
Health Canada recommends that infants should be exclusively breastfed (meaning breastmilk is their sole source of nutrition) until 6 months of age, and that breastfeeding should be continued for up to 2 years and beyond when possible.
When your baby is 6 months old, complementary foods can be added (1). The complementary foods should be rich in the nutrient iron, we’ll talk about why later! (Complimentary foods mean they these foods are in addition to the breastmilk, or formula, that your baby is already receiving).
When mothers are lactating (producing breastmilk), some nutrients in the milk are dependent on your diet – meaning the amounts of the nutrient provided through breastmilk to your baby can vary depending on your diet. Other nutrients, however, will stay at stable levels in breastmilk, regardless of moms diet.
So, which nutrients are dependent on moms diet intake?
B-complex vitamins (thiamine, riboflavin, vitamin B6, and vitamin B12)
Vitamin A
Vitamin D
Selenium
Iodine
Choline
Vitamin C
These nutrients are impacted by maternal diet, meaing that if the mother’s diet is lacking in these nutrients their secretion into milk is rapidly decreased (2,9).
It’s not always easy for new moms to get all these nutrients in their diets. For example, a mothers vitamin A requirements increase from 770 µg/day when pregnant to 1300 µg/day when breastfeeding – this is because vitamin A is an important nutrient for the development of your babies’ eyes (2). Vitamin B12 is another important nutrient to be aware of, especially if you are vegan or vegetarian. Vitamin B12 is found mostly in animal products however, many meat alternative products are fortified with vitamin B12 (2).Vitamin B12 is really important for baby’s brain development, so it’s extra important to make sure you are getting enough in your diet if breastfeeding when vegan or vegetarian.
Vitamin D is also an important nutrient during breastfeeding. It is recommended that a vitamin D supplement (400 IU or 10 µg) is given to infants from birth to one year (1). If the mother’s breastmilk is low in vitamin D, and the infant is not receiving vitamin D supplementation, they are at risk for developing a vitamin D deficiency (1). Vitamin D deficiency can lead to rickets, which is when there is inadequate mineralization of bones, leading to bone deformation(1). The main way we get vitamin D is through sunlight, which can be hard for anyone living in the Canada due to the latitude and cold winters, and most living in Canada are not getting enough Vitamin D (3). However, since it is also recommended that infants under one year avoid direct sunlight (because of their risk for skin cancer), supplementation becomes the main way infants can get vitamin D and decrease the risk of vitamin D deficiency(1).
Now that we’ve gone over which nutrients are dependent on moms diet, let’s discuss the nutrients that are not as dependent on how much we eat!
Folate
Calcium
Copper
Zinc
Vitamin E
Vitamin K
Iron
Phosphorous
Magnesium
These nutrients are less impacted by mother’s dietary intake, and even if the mother is slightly depleted of these vitamins, they will be secreted into human milk until the mother’s stores run out (2,9). This doesn’t mean that you don’t need to worry about eating them! It just means that your body will prioritize getting these nutrients into breastmilk from your nutrient stores, before prioritizing your own health. For example, if moms diet is low in calcium, rather than having low levels of calcium in breastmilk, your body will pull calcium from your bones in order to make sure baby is getting enough. This means that if your diet is lower in calcium, it may not be putting babies intake directly at risk, but it can mean that moms bone health is taking a hit.
Whats the deal with Iron?
Infants are born with iron stores that last up to 6 months, and breastmilk is lacking in iron (1). Since women are not menstruating, and breastmilk does not contain iron, lactating women’s iron requirements actually decrease to approximately 9 mg/d (the amount you need when you are around 9-13 years old!) (4). A babies iron stores are primarily from what they acquired in the womb and through birth (through cord blood), and these stores are typically enough to last until 6 months when we start introducing solid foods. This is why it’s recommended to focus on introducing iron rich foods as your babies first foods, in order to replenish their iron stores and prevent iron deficiency anemia!
It’s not a design flaw that breastmilk is lacking in iron – it’s thought this may actually be in order to prevent infection, as iron is food for pathogenic bacteria that can create havoc in a newborns immature gut.
Ok… but how do I even know if my baby is getting enough milk?
You may be worried that your baby is not getting enough milk, but chances are that they are! When babies are born, their stomach is only the size of a marble (5)! That means that they can only consume approximately 7 mL a day. By day 3 their stomach is the size of a walnut, and by day 10, the size of a golf ball (5). Some great ways to determine if your baby is getting enough milk is if they are feeding often (minimum of 8 feedings per day), the number of wet/dirty diapers per day, and if they are gaining weight. Babies will typically lose 8 oz of their birth weight in the first 3 days, and then will gain around 8 oz per week (on average) for the first 3-4 months (6).
If you think you are not producing enough milk for your baby here are some tips for increasing your milk supply (7):
Breastfeed often – breastmilk production works on a supply and demand system, so increasing demand can increase supply. Look for signs that your baby is hungry (fist in mouth, sucking on hands, lip smacking, opening mouth (8)), typically this is 8-12 times a day for a newborn (7)
Feed your baby at one breast until it is empty and then offer the other – do not switch between breasts until one is empty (7)
If you are feeding your baby expressed milk (pumped milk), pump often (7)
Make sure your baby is latched correctly so that they can feed well. If you think you are having trouble with your latch or position, reach out to a lactation counsellor
Avoid tobacco and drink less than 3 cups of coffee a day (7)
If you have any questions about breastfeeding, including what to eat when breastfeeding, or think that your baby is not receiving enough milk, contact your dietitian or healthcare provider for more information.
References
1. Government of Canada. Nutrition for healthy term infants: Recommendations from birth to six months [Internet]. Government of Canada. 2015. [Cited 2021 March 21]. Available from: https://www.canada.ca/en/health-canada/services/canada-food-guide/resources/infant-feeding/nutrition-healthy-term-infants-recommendations-birth-six-months.html
2. Allen LH. B vitamins in breastmilk: relative important of maternal status and intake, and effects on infant status and function. Adv Nutr. 2012; 3(3): 362-369.
3. Chao YS, Brunel L, Faris P, Veugelers PJ. Vitamin D status of Canadians employed in northern latitudes. Occupational medicine. 2013; 63(7): 485-493.
4. Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc . National Academic Press (US). Washington, DC; 2001.
5. Healthline Parenthood. Your Newborn’s Stomach Size is Smaller than you Think [Internet]. [Cited 2021 March 20]. https://www.healthline.com/health/baby/your-newborns-stomach-size-is-smaller-than-you-think#day-1
6. HealthLink BC. Physical Growth in Newborns [Internet]. [Cited 2021 March 20]. https://www.healthlinkbc.ca/health-topics/te6295
7. HealthLink BC. Breastfeeding and Your Milk Supply [Internet]. [Cited 2021 March 20]. https://www.healthlinkbc.ca/health-topics/ta6433
8. WIC Breastfeeding Support. Baby’s Hunger Cues [Internet]. [Cited 2021 March 20]. https://wicbreastfeeding.fns.usda.gov/babys-hunger-cues
9. Dror, D. K., & Allen, L. H. (2018). Overview of Nutrients in Human Milk. Advances in nutrition (Bethesda, Md.), 9(suppl_1), 278S–294S. https://doi.org/10.1093/advances/nmy022
