What You Should Know About Hydration And Breastfeeding

Breast milk is truly the gift of life. Packed with nutrients and antibodies, it does so many miraculous things, from seeding your baby’s immune system and little GI tract, to providing fluid and essential building blocks for growth. But, for many moms, breastfeeding is a double-edged sword. Aside from the goodness it brings, it can be super-stressful. Exhaustion from disrupted sleep, a baby that won’t latch and also won’t drink from a bottle, low milk production - you wouldn’t think humans have done this for hundreds of thousands of years.

The combination of all, or even some, of these issues is common. And the inevitable guilt – “what’s wrong with me? I’m letting my baby down”, compounds the stress. Neither can be good.

Let’s look a little deeper at the hydration aspects of breastfeeding and some simple things a mother can do to make things better.


Some numbers for context

Lactating women lose approximately 700 ml of additional water per day through breast milk secretion, according to the European Food Safety Agency (EFSA). This puts breastfeeding women at greater risk of dehydration.

It is assumed that an additional 700 ml of water must be consumed to keep hydration levels balanced. Countries have developed Adequate Intake (AI) guidelines for breastfeeding women. However, the recommendations vary widely. To give you a sense, the Institute of Medicine (IOM) recommends 3.3 L of Total Water Intake (TWI) per day, EFSA recommends 2.7 L and the Chinese Nutrition Society 3.8 L. TWI, by the way, includes the water from food – it’s not only what you drink.


Does more water equal more breast milk?

Having just given a guideline for water intake, there seems to be no benefit on breast milk production from drinking more water, as counter-intuitive as that may seem. Many studies show similar results.

Reliable advice is to drink according to thirst. Did you know that oxytocin, the powerful bonding hormone released in mega doses after childbirth, increases thirst? Our hormones are pretty good at telling us what we need. There’s a caveat though. New moms are not always attuned to their own needs, in-between sleep deprivation, fatigue, and figuring out how to adjust to life with a newborn.  And, once we are thirsty, it’s often a little late. We are already dehydrated. So, it’s not a bad idea to drink a glass of water before and after breastfeeding or expressing milk. Don’t force it down – over-hydration is a thing, but it’s a good idea to cultivate the habit.


How do you know if you’re dehydrated?

Symptoms of dehydration are the following. It pays to look out for any of these and ensure that hydration is restored as soon as possible via water and electrolytes.

  • Constipation
  • Dizziness
  • Dry mouth or chapped lips
  • Fatigue and lack of energy
  • Headache
  • Moodiness
  • Muscle cramps
  • Nausea

The colour of your urine is a telling clue. If your urine is dark, it isn't being diluted enough by what you drink. Look for a pale yellow or almost clear colour, which indicates you're getting enough fluids.


What should you drink during breastfeeding?

Your fluids don't have to come only from water, but it's always a good choice. You can add flavour through a squeeze of lemon or soaking cut fruit or vegetables at the bottom of the jug. Oranges or cucumbers are good choices. You can even add herbs.

If you drink water without electrolytes, remember you’re diluting your sodium levels and your body works hard to restore these by dumping water. Ironically, this has an adverse effect on milk production, as fluid levels drop below what is adequate.

Beverages that contain a lot of sugar can reduce the amount of fluid that your body actually retains. This makes dehydration worse, putting pressure on your cooling system and your kidneys, according to a study that examined the effects of such beverages. The same can be said of fruit juices that are high in sugar but low in fibre.

Caffeine can pass into breast milk and affect your baby's mood and sleep. It is also a diuretic, meaning it causes loss of fluid. Caffeine can have a dehydrating effect on your body. If you do have the odd coffee, marry it with water.


Does sodium increase breast milk production?

It’s an old trick of dairy farmers - cows fed more salt produce more milk. The scientific evidence in humans is lacking, but the anecdotal evidence is strong. Many mothers report improved breast milk production when they up their sodium intake. 

The anecdotes come from moms who consume higher sodium electrolyte products like REVIVE, LMNT and Redmond Relyte, and some of the stories have even become marketing campaigns. Kelsey Albers, an American nutritional therapy advisor and strength coach, is one example. After struggling to produce enough breast milk at first, Kelsey increased her sodium intake through an electrolyte supplement with water. Not only did she produce enough for her own needs, but she also managed to donate 28 litres of extra breast milk to a friend who was struggling. The change was instantaneous. Higher sodium seems to assist breast milk production, often quite dramatically.


How much sodium does a breastfeeding mom lose?

A lactating mother doesn’t lose as much sodium as one would think. Breast milk contains about 141 mg of sodium per litre (study reference). Compare this to sweat, which contains about 1,150 mg per litre. That is an 8x difference! If a mother’s daily breast milk volume is 700 ml, this equates to 99 mg of sodium per day for the baby and the same amount lost by the mother. It isn’t that much, even if we consider the much lower weight of a baby, but it’s important.

Now, here’s something interesting to understand – the sodium concentration in breast milk varies considerably by batch, even for the same woman. So, it ‘s not a bad idea to ensure mom isn’t deficient. Between 4 - 6 g of sodium per day is recommended, which includes the sodium from food. So, lets set the target at 5 grams (remember, that’s 13 g of salt). We recommend that no more than 20% come from supplementation, which is 1 g, or 1,000 mg, per day. Natural salt is better than processed salt, for obvious reasons.

By the way, breast milk contains much more potassium than sodium – typically, 480 mg of potassium is found in a litre of breast milk. Moms should remember to eat plenty of leafy greens and avocados. A banana won’t hurt either.


Is more sodium good for my baby?

There is evidence in animals that salt deprivation causes serious adverse effects on the development of the central nervous system. In humans, a study of 46 premature babies showed that those given sodium supplementation for just 10 days (from day 4 - day 14) after birth performed better in language tests and educational attainment a decade later. The results were statistically significant, meaning the difference in performance between the group given salt and the control group is unlikely to be random, while the memory and learning outcomes were also better for the group that received salt supplementation, but the difference was not statistically significant.

How much sodium was given to the babies in this study? For the group that was not given supplementation, the amount of sodium they received in their diet was 34.5 mg per day, and for the group given supplementation, it was 103.5 mg. It is highly relevant that the supplemented group received almost exactly the amount of sodium that is contained in normal breast milk.

By the way, it is worth noting that colostrum (the form of breast milk released for 2-4 days just after giving birth) has nearly 2.3x higher sodium concentration than mature breast milk, indicating the relative importance of sodium for infants immediately after birth. (Reference study here) 

One study doesn’t prove anything, however. The sample sizes in the study were also quite small. Having said that, the results do dovetail with what we know about animals. It would be prudent to conclude that insufficient sodium is a bad idea for developing babies.


Summary Recommendations

For 4 very important reasons, breastfeeding mothers should get sufficient sodium. We recommend 5 g per day (equivalent to 13 g of salt) of which 1 g per day can be supplemented with water and the rest consumed with food.

  1. More sodium is likely to help breast milk production.
  2. Sufficient sodium is important for babies. Babies deficient in sodium may not develop their central nervous systems or brains to their full potential.
  3. Mom will feel better and be less fatigued if she is properly hydrated. Sodium is critical for adequate hydration. We can’t hold water without it.
  4. There seems to be very little, if any, downside.


        Consuming a sachet of REVIVE daily while breastfeeding has the following benefits:

        • It provides the 1 g (1,000 mg) of supplemental sodium mom needs anyway.
        • It helps mom to meet the recommended water intake guidelines* by making the water more palatable and easier to drink.
        • The potassium and magnesium in REVIVE are both essential components of breast milk that also contribute to mom’s hydration.
        • REVIVE has no sugar, chemicals or artificial ingredients. A clean and healthy start to life is something we all need. There will be plenty of time for the bad stuff.


        * Because water intake guidelines vary so much, and they include the water from food, let's simplify things and make it practical. Use the middle of the guideline range, which is 3.25 L per day. Subtract 750 ml for the water contained in food. Therefore, aim to drink 2.5 L per day. Drink more if thirst persists. Make adjustments for activity levels. Adjust further for vomiting or diarrhoea. Consult with a healthcare practitioner if adverse symptoms persist for more than 24 hours or if you take any medication or have a medical condition.


        Cautionary Statement: This article is for interest and information only and should not be construed as medical advice. Check with your healthcare practitioner if you’re unsure of anything or have unusual symptoms. Do not take REVIVE if you have hypertension, kidney disease or take diuretic medication.


        Written by Mark Myerson

        Mark is the co-founder of Revive Labs and a certified keto nutrition and diabetes coach.

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