WHAT WAS CLAIMED
The active ingredient in vitamin K injections, polysorbate 80, is linked to infertility.
OUR VERDICT
False. Polysorbate 80 is not the active ingredient in vitamin K injections and it is not linked to human infertility.
AAP FACTCHECK - The active ingredient in vitamin K injections given to newborn babies is not connected to infertility or autoimmune issues in humans, contrary to an old claim resurfacing in a video online.
Polysorbate 80, the ingredient named in the video, is not the active ingredient in the shots as claimed, and is not linked to either of the conditions.
The video appears in a Facebook post with the caption: "Vitamin K Shot: The Devil's Helping Hand Is Not To Be Trusted."
A woman in the video says (52 seconds): "I had a nurse send me just last week a photo of the box of the vitamin K injection that they give … The main active ingredient is polysorbate 80, and that is, there are strong links to infertility, to autoimmune issues."
A reverse image search showed the original video is from a 2018 segment aired by frequently debunked broadcaster InfoWars.
Vitamin K is an important supplement given to infants to prevent a bleeding disorder known as Vitamin K Deficiency Bleeding, which can lead to brain damage or death.
Babies do not receive enough vitamin K in the womb, which is why a supplement soon after birth is recommended, according to Australian government health advice.
Pediatric medicine experts told AAP FactCheck that polysorbate 80 is present in vitamin K shots as a preservative and has no link to reproductive or immune health issues.
Mark Corkins, a fellow of the American Academy of Pediatrics, said that the main active ingredient is phytonadione, which is vitamin K1, not polysorbate 80.
He said polysorbate 80 acts as a solubiliser for vitamin K, enabling it to dissolve in liquid. It is also a common food additive in products such as Jello.
"There are no links (and I looked deep in the medical literature to be sure) with infertility and autoimmune diseases," Dr Corkins said.
Jaspreet Loyal, an associate professor of pediatrics at Yale School of Medicine, said: "Polysorbate is a preservative and has not been associated with any adverse effects."
Polysorbate 80 is also widely used as a stabiliser in other vaccines such as the HPV and some COVID-19 vaccines, but it is also present in much larger doses in common products such as ice cream, where it is used to make it smoother and to slow down melting.
The Children's Hospital of Philadelphia's website said that the amount of polysorbate 80 in half a cup of ice cream - 170mg - was far higher than the 10mg typically contained in a vitamin K injection.
Claims linking polysorbate 80 to infertility in humans often cite a 1992 study involving rats given much higher doses than those found in the vitamin K vaccine.
While the rats showed signs of reproductive organ impairment, they received polysorbate 80 doses that were 70 times higher per kilogram of body weight than the amount received by human newborns through vitamin K injections, Science Feedback reported.
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