What's the kindest thing a stranger has ever done for you? For Sarah Landis, the answer comes in the form of "liquid gold," neatly stored in bags or bottles, labeled with a date and frozen solid.

The 30-year-old Coon Rapids mother of three has breast cancer and is unable to nurse her youngest daughter, Olivia, who was born 8 weeks premature. Instead, Landis provides the 8-month-old with the milk of 15 different mothers -- all strangers she met over the Internet.

"These women are giving a great gift," said Landis, who's now in remission.

One of those donors is Christa Johnson of Crystal, who has "freezers full of milk" and said it would be "incomprehensible" not to donate her extra milk to families in need of it.

They are part of a growing number of mothers who are using social networking to facilitate connections between women in need of breast milk and those who have milk to spare, despite warnings from the federal government, health care professionals and even breastfeeding advocates about the unregulated practice. They advise families to turn to regulated milk banks, where the donated milk is screened for disease.

In December, after a number of milk-sharing networks popped up online, the Food and Drug Administration issued a warning "against feeding your baby breast milk acquired directly from individuals or through the Internet."

The FDA states that such milk is unlikely to have been adequately screened for infectious disease or contamination risk, and that it's unlikely that the milk has been collected, processed, tested or stored in a way that reduces possible safety risks to the baby.

Shelly Boyce, a registered nurse and lactation consultant for Children's Hospital in Minneapolis, said she understands a woman's desire to get human milk for baby when she is unable to provide it herself.

"Formula cannot replicate what's in human milk, no matter how much stuff they add to it," she said. "But to simply assume that any breast milk is safe because you met a woman and spoke with her over coffee or viewed her medical records from a year prior ... that's being naive."

Even groups that promote breastfeeding, such as La Leche League International, caution against human milk sharing.

"There are risks involved and many of the choices we make as mothers involve a risk/benefit ratio," said Jeanne Badman, a longtime accredited leader in the Twin Cities for the league. "Admittedly, in some people's eyes there's a lot of benefit involved and we know lots of mothers who are doing it, but we're not in a position to recommend or endorse the practice."

Sharing milk over Facebook

Warnings of disease and infection aren't slowing the activity in a Facebook group called Human Milk 4 Human Babies, which facilitates local milk-sharing through nearly 120 Facebook chapters -- one in Minnesota -- in about three dozen countries.

Comments get posted by women who need milk and who have milk to share. Most exchanges take place in person and free-of-charge. The network does not support the sale of human milk.

In a posting last week, a mother from Minot, N.D., offered to deliver milk on her trips to the Twin Cities this summer. An Edina father made a plea to feed his 7-year-old daughter who has a neuromuscular condition that affects digestion and metabolism and "requires breast milk as a critical part of her diet."

"Non-smoking and no prescription meds donor, please," requested Doug Doebbert.

Doug and his wife, Andrea, have been meeting milk donors on the Facebook site for a few months. Prior to that, they sought milk through private donors, milk banks and Milkshare.org, a human milk-sharing website.

"All of the moms I have met with through milk-sharing sites have been wonderful -- caring moms themselves and wanting to make a difference," said Andrea Doebbert. "I think anyone that goes to the trouble of pumping, labeling, freezing, storing and opting to donate are caring individuals who want to help."

Health experts encourage mothers -- and fathers -- to instead get milk from formal milk banks, such as the ones that are a part of the Human Milk Banking Association of North America, a network of nonprofits. Besides being screened for disease, the donated milk is pasteurized before it's made available.

The closest association milk banks to the Twin Cities are in Iowa or Colorado, but locally, women can donate milk to the Milk Bank at the University of Minnesota Medical Center, Fairview. The donated milk is shipped to Prolacta Bioscience of Monrovia, Calif., where it's modified to ensure that every ounce has a precise number of calories and nutrients, and is sold back to hospitals.

The qualification procedure is rigorous and as many as three donors are turned away each month.

"Our commitment is to the health and safety of the babies," said Mark Spitzack, Milk Bank coordinator. "We have to turn away quite a few nursing moms -- as many as three a month."

The most common reason for denial is medications, even over-the-counter meds like Tylenol and herbal supplements meant to increase milk supply. Milk is also rejected if the donor didn't store it at the right temperature. Even one degree off can lead to rejection.

Sure, the milk bank is a safer option, mothers say, but at $3 to $5 an ounce, cost is the biggest obstacle. For a baby who takes in 25 ounces a day, that's $525 to $875 a week. Plus, donor milk is often reserved for the sickest babies. And without a doctor's prescription and insurance approval, the money comes out of pocket.

"If insurance would cover it, I'd be happy to get milk from a milk bank," said Landis, who said she has driven in snow storms and across the state in search of the "perfect nutrition" for her daughter. "Until that happens, I'm going to continue doing what I have to do to give my daughter the best nutrition."

Aimée Tjader • 612-673-1715