WASHINGTON, D.C.: Doctors across the country are worried about growing anti-science attitudes, as mistrust in medicine is spreading beyond vaccines to other routine and proven preventive care for babies.

A recent study in the Journal of the American Medical Association examined more than five million births nationwide. It found that the number of parents refusing vitamin K shots for newborns almost doubled between 2017 and 2024, rising from 2.9 percent to 5.2 percent.

Other studies show that parents who refuse vitamin K shots are also much more likely to reject other basic care, like the hepatitis B vaccine and an eye ointment that prevents serious infections. Doctors say fewer babies are getting the hepatitis B shot at birth, and more parents are also refusing the eye treatment.

At a hospital in Idaho, Dr. Tom Patterson noticed that half of the newborns did not receive vitamin K shots, which have been used for many years to prevent dangerous bleeding. On another day, more than a quarter of parents refused routine shots for their babies. Patterson said it worries him to see a simple and long-used treatment being refused for vulnerable newborns.

Dr. Kelly Wade, a newborn specialist in Philadelphia, said most parents care deeply about their babies, but many feel confused because they are getting mixed information.

Social media has many posts questioning doctors' advice on safe treatments like vitamin K and eye ointment. At the same time, actions by the Trump administration have also raised doubts about established science. A federal advisory group, whose members were chosen by Health Secretary Robert F. Kennedy Jr., voted to stop recommending hepatitis B vaccines for all newborns, but a federal judge later paused that decision.

Dr. David Hill, a pediatrician in Seattle, said a common belief among some parents is that natural methods are always better than medical treatments. However, he explained that in the past, many babies died in their first year, which is why medical care has improved survival rates.

Newborns naturally have low levels of vitamin K, which helps blood clot. Without it, babies can suffer serious bleeding, including in the brain. Doctors say that before vitamin K shots became common, about 1 in 60 babies had this condition. Today, it is rare, but babies who don't get the shot are much more likely to develop severe bleeding.

Doctors in Idaho reported eight deaths from vitamin K deficiency bleeding in just over a year.

Other newborn treatments are also important. The eye ointment protects against infections such as gonorrhea, which can cause blindness, and the hepatitis B vaccine protects against a disease that can lead to liver failure or cancer. Doctors say even if mothers are tested during pregnancy, there is still a chance of infection later, which can be passed to the baby.

Parents refuse these treatments for different reasons, such as fear of side effects or not wanting their babies to feel pain. Social media also spreads false information and promotes vitamin K drops, which doctors say are not absorbed well by babies.

Doctors in many places say that parents who refuse vitamin K shots often reject other types of care, too. One doctor in Illinois even saw a family refuse a simple blood test for a baby at risk of dangerously low blood sugar.

Doctors say refusing care is not new, but it used to be rare. Now, it is becoming more common.