Social media has been awash in panic as one influencer after another wrongly warns prospective parents against the routine (and sometimes life-saving) vitamin K shot, given to newborns right after birth. Claims linking it to pediatric cancer, eczema and other serious conditions are spreading rapidly online, leaving many new moms and dads alarmed and confused.
Vitamin K plays a critical role in blood clotting by activating coagulation factors that prevent excessive bleeding from everyday bumps and injuries. Newborns are born with very low levels of it. The vitamin doesn’t cross the placenta efficiently, their guts are initially sterile with no bacteria to produce it naturally and breast milk provides only limited amounts that aren’t well absorbed. This leaves infants vulnerable to vitamin K deficiency bleeding (VKDB), which can cause catastrophic brain bleeds leading to death or lifelong neurological damage.
Before the shot became standard practice, early and classical VKDB affected roughly 250 to 1,700 newborns per 100,000 births, with late-onset cases occurring at 4.4 to 7.2 per 100,000. In severe instances, one in five babies died. The simple intramuscular shot has reduced this risk dramatically—to less than 1 in 100,000. It is not a vaccine, just a necessary vitamin supplement.
An early 1990s study suggesting a possible cancer link has been thoroughly debunked by subsequent research. Concerns about jaundice or rare side effects often stem from outdated formulations or unrelated newborn conditions, such as immature liver function. Higher-risk infants, including those whose mothers were on certain anticonvulsants or anticoagulants during pregnancy, benefit most from the intervention.
Unfortunately, refusals have risen sharply — from around 15,000 in 2017 to 37,000 in 2024, fueled by recycled misinformation and influencers capitalizing on fear. Algorithms amplify scary content, distorting parents’ risk assessments and putting more children at needless risk of devastating outcomes.
Parenthood brings enough real challenges. This safe, evidence-based shot prevents entirely avoidable harm. Seek out credible sources, question sensational claims, and prioritize data over viral videos.
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Join Dr. Liza Lockwood and Cam English on this episode of Facts & Fallacies as they challenge viral nonsense about the Vitamin K shot.
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Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD
Cameron J. English is the executive vice president at the American Council on Science and Health. Follow him on X @camjenglish
