(NewsNation) — Stores have been struggling to stock enough baby formula nationwide, leaving many parents left wondering where they will now find their baby’s next meal.

Nearly 40% of popular baby formula brands were sold out at retailers across the U.S. during the week starting April 24, according to an analysis by Datasembly

This is cause for concern as moms and dads are not able to get their hands on some of the most popular brands of formula.

There are two factors to consider causing this formula shortage:

• The first is that the largest makers of baby formula are having difficulty getting some of their critical ingredients.

• Second, a large recall of baby formula earlier this year exacerbated already existing supply issues.

Well-stocked shelves of formula at stores are now a rare sight, and recent manufacturer recalls seem to be worsening the situation.

Abbott Nutrition voluntarily expanded a recall of powder formulas manufactured at one plant after the deaths of two children, both of whom had reportedly consumed Abbott products.

Officials say several others were hospitalized with bacterial infections.

Analysis by Datasembly found that 31% of formula products were out of stock across the country.

Prolific neighborhood pharmacies Walgreens and CVS moved to limit customers to three formula products per purchase, both in stores and online.

Doctors recommend against substituting something like milk for your child’s formula or breast milk, calling it vital in a child’s first year of life.

And when looking for formula in stores, grab what’s available, “It’s important for families to realize that a lot of the store brands or the off-brand formulas are still FDA regulated and they’re still safe and most babies would be just fine.”

The major producers of baby formula say they hope to get supplies back up, but there’s no timetable just yet. If you have any questions about baby formula, you should consult your family pediatrician.