DENVER (KDVR) — A nationwide shortage of baby formula has some Colorado families very concerned.

With supply chain issues and some national recalls, the out-of-stock rate for baby formula is now at 40%, according to Datasembly. Some major retailers, including Walgreens, are now limiting the amount of formula that people can buy at one time.

Allie Ratner said her 5-month-old, Olivia, just started using baby formula.

“Shelves in here are pretty bare,” she said while walking out of one store. Ratner noticed supply is low, but her family has been able to find formula.

“We were able to find some at Costco last week, my husband was able to find it, but they are limiting the Kirkland Brand,” she said.

Advice for parents during baby formula shortage

Laura-Anne Cleveland is the associate chief nursing officer at Rocky Mountain Hospital for Children, and she has some advice.

“Please know that it is ok to switch formulas, but what is important to do is to look at the back of the formula: See if you can match the carbohydrates, the proteins and it’s OK even to do generic brands,” Cleveland said.

She said there is a chance that a change in formulas can cause a stomachache, so if possible, mix the two brands as you transition.

Cleveland said do not give an infant a formula meant for toddlers. Do not use cow’s milk before a doctor says it’s OK. Do not dilute the formula, do not try making your own and be cautious if buying from an online marketplace.

“You don’t know necessarily the age of it, or how someone stored formula,” she said.

If you can’t find what you need, Cleveland suggests asking hospitals or doctors offices if they have any samples they can give to you.