Today I wanted to share a post from Dr. Alicia Hart at Vitality NW, a primary care clinic in Bridgeport Village. Dr. Hart is a naturopathic doctor who specializes in preconception, early childhood and family medicine. She has three children, the first one she nursed for 21 months and currently still nursing her 17 month old twins! She offered to share her expertise on this subject related to nutrition during lactation.
As a culture we focus a lot on what people should or shouldn’t eat in pregnancy. No shellfish. No deli meat. No soft cheese. No coffee. The list goes on and on and on. When it comes to nursing babies, suddenly there’s a vacuum of knowledge for social supports, and information is really conflicting. Part of the reason for this is that it’s really hard to study diet in general, and a lot of nutritional studies have big flaws because of the complications of feeding people for research. Additionally, nutrition is only one of many factors that relates to a successful nursing relationship that lasts up to the 2 years that the WHO recommends. Fortunately, breastmilk composition is much the same independent of country, race, age, and diet, with exceptions for extreme cases. Breastmilk can vary more between people in the same city than between two people across the world! However, there are still a few things to keep in mind while you’re eating, and I’ve got a big list plus a TL;DR summary at the end.
First, let’s talk about the big breakdown: calories and macronutrients
Per baby, you need to add 500 calories per day on top of your basal metabolic rate. That’s more than pregnancy, and a lot of moms will feel that hungry! Breastfeeding hungry is on another level, and you should honor that your body is telling you to eat.
500 calories comes out to a meal (or a big fancy starbucks holiday frappucino, though that kind of calorie can mess with your blood sugar balance), rather than the extra snack per day for the intrauterine part of feeding a kiddo. Note that I did write “per baby”, so yes, add that up if you have twins, triplets, or more. Feeding babies is a lot of work! Even if you feel like you’re trapped on the couch doing nothing (which is basically those first three months or more anyway) you’re still burning around the same amount of calories that you would if you ran for almost an hour. When you return to an active lifestyle after getting cleared for exercise, those fitness calories count too. Make sure you’re eating enough, the dietary requirements of breastfeeding can be more than you expect.
What should those calories be made out of?
I’m a big fan of a higher protein diet, 60-100 grams per day, because you are literally building a human. Human milk contains more than 200 different proteins, mostly for immune function, but also neurotransmitters and just absorbable protein components. Good sources of protein include nuts, seeds, beans, eggplant, tofu and meat.
The dietary component that has the biggest effect on the composition of milk is your fat intake. Fat is the primary source of energy for the baby in breastmilk, and so if you’re not eating enough to transfer, your breasts will make it for you. However, eating different kinds of fats can influence the balance of different kinds of fats, known as Omega 3’s and Omega 6’s. Omega 3’s are the ones that your kid will primarily build their brain out of, and enough of one of the omega 3’s called DHA has some pretty impressive stats for neurodevelopment on down the line, as measured at age 4 and above, including:
improved vision function and attention
higher mental developmental index
better problem solving
higher test scores
You can find more optimal omega 3 levels in fish, flax seed oil, chia seeds, walnuts, soybeans, spinach, and seafood. If you’re choosing to get your omega 3s from fish or fish oil, make sure you’re trending towards smaller fish and being careful of your heavy metal intake- the reason pregnancy guides say to limit tuna fish is because of the mercury contamination from pollution. Aim for 2-3 servings of smaller fatty fish per week, or 1,000 to 3,000 mg per day of fish oil. Most studies use a dose around this size but as with all nutrition science, it gets a bit messy with portion sizes and individual variance, so there are no exacts.
Side Note/ Different soapbox: Tuna and similar larger fish should be eaten more on the once monthly type of scale than the weekly scale because contamination risk is so large. You know that if even the American academy of pediatrics has a stance on consumption of mercury containing fish, it’s a big deal.
And that leaves us with carbohydrates for macronutrients. Some people find that the balance of carbohydrates can be difficult while they maintain their supply. 1/2 a plate of veggies at every meal is great for the vitamins, minerals, and fiber, but completely avoiding grains seems to decrease output for many. 1-2 servings per day of whole grains like rice, quinoa, and oatmeal can be the answer for the boost. Think about sweet potatoes and fruits as filling this space too! It’s important to have enough carbs to support the huge metabolic process that lactation is, while avoiding the excess that can cause insulin resistant and blood sugar dysregulation. In other words, you can only live on “lactation cookies” for so long before you run into other problems.
Now, let’s talk micronutrients:
Calcium. Everyone wants to know about calcium. During pregnancy, your body absorbs more calcium from your dietary intake and prevents you from losing it the way you normally would. During lactation, your body doesn’t care so much about diet and just takes the mineral right out of your skeleton. During nursing you can lose a big chunk of bone density, but don’t worry- you get an extra period of bone rebuilding for the year after you finish nursing. That’s why nursing has long term protective benefits against osteoporosis for most women, as you can increase bone mass outside of those teen years which are normally so important. However, for women who had an inadequate intake of calcium during the whole process of making the tiny human, this can result in some deficits like “nursing cavities” which can be so extensive they even lead to early dentures, and in extreme cases, even osteoporotic fractures. Make sure your intake is adequate for your needs and really focus on calcium right after weaning, while avoiding high phosphorus intake like soda. Calcium does not only come from milk and cheese- the calcium in dark leafy greens is actually more bioavailable. Legumes, fruit, sardines, salmon, and almonds are also good sources for your gram a day.
Vitamin D: If mama is getting 6400 IU of vitamin day daily, baby doesn’t need a supplement to reach their 400 IU daily requirement. It’s also more convenient for mama to take a supplement, or be outside enough, to get that vitamin in. Keep in mind that there are a lot of components to absorbing vitamin D outside, including the time of year, the geographical location on the globe, how much clothing you’re wearing, and what color your skin is. In the last 60 years, we’ve become even more indoor oriented than we used to be, making it really hard to get that vitamin D in through sunlight or mushrooms.
Vitamin B12, B6 and Folate all cross through breastmilk, and they’re all very important for helping cells divide, metabolism, and neurological function.
B12 is obtained almost exclusively through animal products (the exception being huge amounts of seaweed) and newborns are particularly vulnerable to b12 deficiency, which can contribute to developmental factors. To bring that level up, supplementing 1000 mcg per day is appropriate.
B6, or pyridoxine, is less hard to get through your grains and veggies, and low levels don’t seem to effect baby as much as they do mama. There’s not a lot of good research on what happens for baby in maternal deficiency states though science supports maintaining a good store of b6, which is 15 mg per day. Low levels in mother can have some interesting psychiatric symptoms and nausea, neither of which are great symptoms to have daily.
Folate has been somewhat talked to death for prenatal health and preventing some midline deformities of infants. The primary form that is in breastmilk is 5 methyl tetrahydrofolate. Folate deficiency happens particularly on a diet depending on those refined carbohydrates.
If you were deficient in any of these B vitamins before, you will become more deficient as nursing goes on, because breastmilk prioritizes sending these nutrients over to baby. Some people have trouble turning B12 and folate into their active forms due to a common genetic mutation called MTHFR, so you may need to bring in a special form of these vitamins depending on your own processing. You need to maintain your own stores for your own metabolic functions, so don’t let breastfeeding deplete you further. Supplementing your intake of these nutrients may also increase your milk supply- those B vitamins are the main reason brewer’s yeast gets added to lactation cookies.
Vitamin A is critical for immune system function, and breastmilk is an important source of this fat soluble vitamin until weaning (which, remember, worldwide happens at much later age than here in the united states) Additionally, supplementing vitamin A seems to increase maternal hemoglobin stores, so there’s some anemia preventing magic right there. 3000 IUs as beta carotene (think carrots, pumpkins, and all vegetables orange) is the studied dose. The improved immune function from adequate vitamin A levels in an intervention trial in a vitamin A deficient area prevented 49% of mortality. Quite the benefit to pass on to baby.
Selenium and Iodine
Breastmilk supplies both of the cofactors needed for the infant’s thyroid to work properly. Since the thyroid sets the beat for metabolism and brain development, it is really important to make sure these levels are at an optimal level for the duration of the nursing relationship. The WHO recommends 250 mcg per day of iodine to prevent goiters. Iodized salt and sea vegetables are great sources of this, as are cranberries.
Selenium is a trace mineral needed for the thyroid hormones to activate once they leave the thyroid, and I frequently see deficiencies of this in adults in my practice, just in general. 2 brazil nuts a day supply the needed 15 mg daily, which transfers easily into breastmilk.
Tiny iron shout out: maternal iron stores during lactation don’t affect baby’s chances of anemia, and breastmilk generally doesn’t have enough iron to prevent anemia past around 6-9 months. That’s why traditional weaning foods and Canada’s first food recommendations are things with higher iron, like meat, eggs, things cooked in a cast iron pan. However, maternal stores of iron during pregnancy are really important for preventing anemia in babies, because iron absolutely crosses the placenta.
Wow, that’s a lot of information! What’s the TL;DR?
-Eat enough food. 500 calories extra per baby per day.
-Eat fats, focusing on healthy fats. Try to up your Omega 3 and DHA dietary content.
-Eat enough protein. Aim for 60- 80 grams of protein per day.
-Eat vegetables in all the different colors.
-Eat enough carbohydrates in the form of whole grains, potatoes, and squash. Refined carbs and too many carbs can mess with your blood sugar levels.
-Especially make sure you get enough of the following:
– 6400 IU of Vitamin D per day
-1000 mcg of Vitamin B12 per day
– 15 mg of B6 each day
– 800 mcg of folate each day
– 250 mcg of Iodine each day
– 15 mg of selenium each day
-3000 IU of Vitamin A as beta carotene each day
Focus on enough Iron and dietary calcium during pregnancy, and focus on calcium during the year post weaning when you build your skeleton back up.
http://advances.nutrition.org/content/3/3/362 full B vitamins (may 2012)
https://www.ncbi.nlm.nih.gov/pubmed/19178515 iodine (may 2009)
http://ajcn.nutrition.org/content/81/5/1206S.full.pdf+html micronutrients (may 2005)
https://www.ncbi.nlm.nih.gov/pubmed/26887676 maternal skeleton, calcium, vit D (april 2016)
https://www.ncbi.nlm.nih.gov/books/NBK235579/ energy reqs, RDAs (1991)
http://www.who.int/mediacentre/factsheets/fs342/en/ who reqs, (sept 2016)
https://www.ncbi.nlm.nih.gov/pubmed/26375355 human milk composition (nov 2015)
http://ajcn.nutrition.org/content/99/3/734S dietary impacts on neurodevelopment (feb 2014)
Thanks Dr. Hart for the excellent information!