Can Supplementation Increase Zinc in Breast Milk? Here’s What the Research Says. (Plus a Note About Zinc Levels in Formula VS. Breast Milk)
For the First 6 Months of Life, Zinc Concentration In Breast Milk Is Affected By Mother’s Diet
In 2022, it goes without saying that a pregnant mother’s diet will impact the health of her baby. With zinc specifically, having good fetal stores to start off life will help to protect that baby from future zinc deficiency.
After birth, a nursing mother’s personal zinc levels will affect the levels of zinc found in her breast milk. It’s important for both mom and baby to get enough zinc so that mom can recover and her baby can grow strong.
Luckily there are lots of delicious foods that are high in zinc and supplementation options if needed. Most high quality prenatal vitamins will contain a good dose of zinc. I often recommend that nursing mothers continue taking their prenatal vitamins for the first six months of nursing to keep their own stores of vitamins and minerals high while being able to provide everything they need for their breastfed baby.
After 6 Months, Breast Milk Zinc Concentration Isn’t Affected By Mother’s Diet
There isn’t a lot of research, but from what we know so far, it seems that zinc concentration of breast milk from healthy women isn’t impacted by supplementation after 6 months of age.
Note: if the mother is deficient in zinc, correcting a zinc deficiency in the mother improves the quality of her breast milk.
After 6 Months, Breast Milk Doesn’t Contain Enough Zinc
Breast milk is miraculously adapted to change as the needs of the baby change. It’s composition changes in some predictable ways including a decrease in zinc at around 6 months. At 4-6 months the breast milk concentration of zinc starts to decrease and most babies no longer meet their developmental needs through breast milk alone.
At 6 months of age, most babies need zinc rich foods and/or zinc supplementation to keep their levels optimal.
How Does Formula Compare to Breast Milk When It Comes to Zinc?
When it comes to zinc, formula fed babies may come out ahead of breast fed babies. One study found that 14.9% of breast fed babies aged 4-6 months were deficient in zinc. The same study found that only 5.3% of formula fed babies were deficient in zinc, and that for babies who had a mix of breast milk and formula only 2.9% were deficient in zinc.
Another study, looking at how well zinc was absorbed, showed that zinc in formula made from cow milk was almost twice as bioavailable as formula made from soy! I didn’t find information about whether this difference in absorption translated into a higher likelihood of zinc deficiency or not, but it is something to keep in mind.
A Note About Milk Banks and Zinc
Milk banks are wonderful and have many health benefits. However, one thing to keep in mind is that pooled breast milk in milk banks will often be from mothers with older babies. This means that the zinc concentration in milk from a milk bank may be too low for a younger infant. These babies may benefit from a zinc supplement and/or a mixed diet that includes a high quality formula.
How To Ensure Your Baby Is Getting Enough Zinc
The best time to prevent a zinc deficiency is during pregnancy. The second best time is now.
During the first 6 months of life, ensuring that a nursing mother has enough zinc will likely ensure that her baby has enough zinc too. After 6 months, most babies need more zinc than nursing alone can provide so it is time to start introducing zinc rich food and/or supplements.
Formula fed babies are less likely than breast fed babies to develop a zinc deficiency, but it is still possible, especially if the baby was born with low zinc, or with certain health conditions that can lead to zinc deficiency.
Babies who get their nutrition from soy based formula and/or breast milk banks may be at increased risk for zinc deficiency.
Mild to moderate zinc deficiencies are tricky to diagnose because the most common symptoms, such as slow growth and increased infections can be caused by many things. A more serious zinc deficiency shows up as a rash that looks like eczema around the mouth and in the diaper area along with diarrhea and irritability. If the rash doesn’t improve with corticosteroid treatment, that is a key sign that the rash is from zinc deficiency rather than allergies and that supplementation is needed.
The most important thing for parents is to pay attention to your individual baby’s growth, development, health, and nutrition and to reach out for help to a nutrition savvy healthcare professional if you suspect your baby might not be getting the nutrients they need.
Zinc is quite safe to supplement if you stay within the guidelines, and the consequences of an untreated deficiency can be serious.
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