For more than a decade, Dr. Joseph Mercola cautioned parents against a potentially lifesaving shot of vitamin K for their newborn babies: “Vitamin K shots are completely unnecessary for your newborn.”

But now, in a break from his past warnings, Mercola is saying he no longer believes that. 

ProPublica contacted Mercola recently as it was preparing an article about babies who died as a result of their parents turning down the vitamin K shot. Mercola’s new point of view is just as unequivocal as his old one: “The data is clear: vitamin K saves lives,” he wrote in an April article on his website two days after ProPublica contacted him. He added: “Based on the totality of the published evidence, I support vitamin K prophylaxis for all newborns.” 

He also directed parents to speak to their children’s pediatricians. 

“Vitamin K deficiency bleeding is rare, but when it occurs, the consequences can be devastating and irreversible,” Mercola wrote. “A single injection at birth can prevent it. Please talk to your doctor.”

Mercola is a leading vaccine skeptic and an ardent supporter of Health and Human Services Secretary Robert F. Kennedy Jr. He is a popular figure online, with a Facebook page that has some 1.7 million followers. He sends out a daily newsletter and sells alternative treatments for a variety of ailments. 

His reversal comes at a critical moment. Hospitals and research studies have documented an alarming jump in babies not receiving the vitamin K shot, which has been recommended by the American Academy of Pediatrics since 1961 to help newborns’ blood to clot. Without it, research shows, babies are 81 times more at risk for late vitamin K deficiency bleeding, which can be fatal. 

Just as has happened with measles and other vaccines, vitamin K shots have become the target of a deluge of false information online. That has caused some parents to view it as an unnecessary pharmaceutical intervention amid a lingering mistrust of the medical system following the COVID-19 pandemic. 

Some point to a 2010 post from Mercola, entitled “The Dark Side of the Routine Newborn Vitamin K Shot.” A doctor in Tennessee recalled reluctant families citing the article, as did doctors in Oregon. 

In the years that followed, Mercola stood by his opposition. He reiterated his position in 2014, after four babies in Nashville, Tennessee, suffered vitamin K deficiency bleeding. And he did so again in 2019, after hospital staff contacted child protective services in Illinois and took temporary custody of a newborn whose parents refused the shot for their baby.  

In place of the shot, Mercola had recommended vitamin K drops, which are taken orally and have been touted online as a popular alternative. The drops, however, are not approved by the Food and Drug Administration and research shows they are not as effective as the shot, though they are used in some European countries. 

In his April article, he addressed the rampant false information online regarding the vitamin K shot and acknowledged the role his writing may have played in spreading it. “The internet contains a significant amount of misinformation about vitamin K,” Mercola wrote. “Some of it may reference my own 2010 article. That article reflected the state of a scientific debate that has since been resolved. The science moved forward, and so have I.”

In fact, the science around the vitamin K shot has been settled for decades. The discovery of vitamin K and its role in clotting blood won the Nobel Prize in 1943. Newer studies have confirmed and furthered many of the findings that were available in 2010, but they do not represent a scientific shift from previous research. Some recent studies that Mercola cited in the April article document the rise in babies not receiving the shot and the catastrophic bleeding in the brain that can follow, but again both reinforce the same science that has encouraged giving the shot for more than 60 years. 

In Mercola’s earlier posts, he wrote about what he deemed to be risks from the shot, beginning with “inappropriate” and “unnecessary” pain to the baby. He incorrectly claimed that the amount of vitamin K injected into newborns was far more than the needed dose. In addition, he wrote that the shot may contain preservatives that can be “toxic” to a baby’s immune system. 

Benzyl alcohol is often used as a preservative in vitamin K shots, but the Centers for Disease Control and Prevention and other organizations have stressed that it’s safe. In the 1980s, doctors realized that some extremely premature babies suffered benzyl alcohol toxicity, but, according to the CDC, that was because they were on so many medications containing it. In addition, many hospitals now offer preservative-free options.

Some families have also expressed fear about a “black box warning,” which appears on a drug’s label to alert providers of serious risks. The shot does contain a boxed warning, as do more than 400 other medications, but that is primarily related to adults and vitamin K that is given through an IV, not as a shot in the thigh muscle, which is how doctors typically administer vitamin K to babies. None of the dozens of doctors interviewed by ProPublica said they have ever seen an adverse reaction in an infant who received a vitamin K shot.

But even back in 2010, Mercola dispelled one popular misconception that vitamin K injections increased the risk of cancer. That belief stemmed from a pair of older refuted studies. In 2010, he wrote, “that conclusion was in error.” In April, he reinforced that message.

Alternative treatments promoted by Mercola have attracted federal scrutiny. He and his companies have had to pay millions of dollars to settle allegations that he had made false claims about the safety of products. 

During the pandemic, for instance, the FDA sent Mercola a warning letter after he offered unapproved and misbranded products, including vitamin C, on his website as ways to prevent or treat COVID-19. 

In 2017, the Federal Trade Commission announced it was mailing $2.59 million to people who bought Mercola indoor tanning systems. The agency charged that Mercola and his companies claimed the tanning systems were safe and that research showed that indoor tanning doesn’t raise the risk of melanoma, a type of skin cancer. 

Mercola did not admit wrongdoing. His online posts include a disclaimer that they are intended as a way of sharing knowledge and information, not medical advice. He also has said his 2010 vitamin K article was based on an interview with a Dutch researcher who studied vitamin K.

Mercola, a doctor of osteopathic medicine, declined to be interviewed for this story but said his current stance is accurately reflected in the April article. “While I do not agree with all of the characterizations and conclusions in your summary,” he wrote in response to questions from ProPublica, “I have nothing further to add at this time.” 

Even though Mercola has now reversed his position on vitamin K, many on social media still cling to debunked and distorted claims. On Facebook, TikTok and Instagram, unsubstantiated claims often go unchecked.

One theme that has emerged on social media is the notion that God created babies perfectly, and there must be a reason they are born without sufficient vitamin K. In one video on TikTok, a woman who identifies herself as a nurse asked, “Did God really get it wrong?” 

Responding to another, someone wrote, “Just know our creator didn’t make a mistake. Every baby is born like this for a reason.” 

Others lump the vitamin K shot, which is not a vaccine, in with vaccines. A comment on a video about the vitamin K shot declared, “My baby isn’t getting any vaccines.” It received more than 600 likes.

Mercola also is not the only doctor being cited by vitamin K shot opponents. Commenters on Instagram, TikTok and Reddit have directed people to Dr. Suzanne Humphries, who has spoken out about vaccines and the vitamin K shot for many years. 

“My opinion is that the more I read about vitamin K,” she said in a video posted in 2014, “the more I can’t believe that it’s injected into newborn infants.”

Last month, she appeared in a lengthy interview on the website of Children’s Health Defense, the anti-vaccine nonprofit founded by Kennedy. She cited the pair of studies from more than 30 years ago that found an association between the shot and cancer, though they were both called into question shortly after they were published. As even Mercola noted in 2010, several additional studies found no increased risk of cancer following the shot. 

“Those of us that believe in a divine creator,” she said, “believe that maybe it is by design, or that actually it is by design, and that there’s a reason for it.” 

Humphries did not respond to requests for comment.

During Kennedy’s time at Children’s Health Defense, the group published a post in 2020 that claimed aluminum adjuvants — added components that boost the body’s immune response — in vaccines are “significant sources of early exposure” to aluminum. Some vitamin K shots contain a small amount of aluminum, but studies have not found any evidence of serious or long-lasting harm. Adjuvants, according to the CDC, have been used “safely in vaccines for decades.” 

Brian Hooker, chief scientific officer at Children’s Health Defense, said the aluminum concern remains, as does the cancer fear, despite multiple studies that found no basis for them. He said he would like to see more research on the vitamin K shot, as well as other newborn interventions like the hepatitis B vaccine. 

“I do want to look at the individual components of these shots in conjunction with everything else that the infant is getting,” he said, “and to me that body of literature is really incomplete.”

Hooker said he worked with Kennedy for many years and, while they are no longer in direct contact, he has full confidence in the country’s leading federal health official. But Kennedy’s silence has served to deepen skepticism among experts. 

“Now we’re starting to see something that I never saw, which was brain bleeds and gut bleeds in infants,” said Rep. Kim Schrier, a Washington Democrat who worked as a pediatrician for more than 15 years before running for Congress. “And that’s so scary and heartbreaking.”

At an April House subcommittee hearing, Schrier confronted Kennedy about vitamin K, saying that he made parents distrust doctors and shots, and as a result some parents are refusing the vitamin K shot and other standard care. 

“Right now, Secretary Kennedy, given what I just told you about vitamin K, will you just tell pregnant women out there for the record, ‘Yes, you should get your babies the vitamin K shot’?” Schrier asked Kennedy.

Kennedy did not oblige her. He said he has never said anything about the vitamin K shot. 

An HHS spokesperson did not answer ProPublica’s questions but said the CDC recommends that parents give newborns the vitamin K shot within 6 hours of their birth to prevent vitamin K deficiency bleeding. She acknowledged that uptake of the shot has declined during recent years “as public trust in health care institutions has fallen, particularly during the COVID-19 pandemic amid heavy-handed mandates and inconsistent messaging during the Biden administration.”

“Rebuilding that trust,” the spokesperson wrote in an email, “requires honesty, informed consent, and respect for individual choice.” 

Schrier said she empathizes with parents who are inundated with so many conflicting messages. She said she recently stepped out of the Capitol building and overheard a woman say — inaccurately — that every childhood vaccine contains glyphosate, which was an ingredient in some forms of the weed killer Roundup. 

“I can just see how this is going to spiral right now. It gets out there, then it’s on social media,” Schrier said. “Every parent just doesn’t want to do the wrong thing.”