FULL CLAIM: Vitamin K shots are poisonous because they contain polysorbate 80 as “main active ingredient” that has “strong links with infertility, with autoimmune issues”; “They have poisoning [sic] our babies for decades”.
Vitamin K Deficiency Bleeding (VKDB) is a potentially fatal condition where the lack of vitamin K in newborns impairs blood clotting and causes hemorrhages. VKDB occurs in one in 60 to one in 250 newborns. Since the 1960s, newborns generally receive an injection of vitamin K at birth to prevent VKBD. The presence of vitamin K supports blood coagulation and thus reduces the risks of hemorrhage. According to the U.S. Centers for Disease Control and Prevention, newborn babies who don’t get vitamin K injections are 81 times more at risk of VKDB than those who get the shot.
However, the rise of vitamin K hesitancy has led to more and more newborns not receiving the preventive vitamin K injection.
A recurring claim fueling that hesitancy is that vitamin K injections contain dangerous ingredients. An example is the allegation by the late anti-vaccine activist Brandy Vaughan that vitamin K injections contain a molecule called polysorbate 80 as “main active ingredient” that has “strong links with infertility, with autoimmune issues”. She also added that polysorbate 80 was “banned in a lot of countries”.
Vaughan made that claim in 2018 on conspiracy theorist Alex Jones’ Infowars website, rated as a website of low credibility by Media Bias/Fact Check. The claim resurfaced in May 2023 on social media in this Facebook reel, which also contained the text “They have poisoning [sic] our babies for decades”.
This isn’t the first time that polysorbate 80 is cited as evidence of a medicine’s toxicity. Indeed, several claims also allege that the molecule’s presence in some vaccines is evidence that vaccines are dangerous. All these claims, however, are baseless. Polysorbate 80 is a common food additive that isn’t associated with infertility or autoimmunity.
Polysorbate 80, also referred to as PS80 or Tween 80, is a fatty molecule used as a solubilizer or an emulsifier. This means that it helps other molecules to dissolve and keep ingredients well-mixed. Therefore, it is also an ingredient in many industrially-processed foods, like ice cream, gelatin desserts or barbecue sauce.
Polysorbate 80 is also an ingredient in some vitamin K injections. However, contrary to what Vaughan claimed, polysorbate 80 isn’t the “main active ingredient” of vitamin K injections. An active ingredient is the molecule that exerts a direct therapeutic or medical effect. In the case of vitamin K injections, the active ingredient is the vitamin K itself. Polysorbate 80 is actually an excipient.
“Parents should not be concerned about the concentration of polysorbate 80 in the vitamin K shot […] P80 is designated by the (US Food and Drug Administration) as generally recognized as safe […] While there are limited studies about P80, no adverse effects have been reported in infants who received vaccines with P80.”
In fact, children are much more exposed to polysorbate 80 through food and drink than through vitamin K injections or vaccines. Christine Gold, a pediatrician at UCHealth University of Colorado Hospital, told USA Today that “a baby who grows up to ever put his or her hand in their mouth, or whoever takes a bite of ice cream, will see more of those stabilizers/buffers at that time than all of the vaccines or vitamins we inject combined.”
The Children’s Hospital of Philadelphia also explained that “A typical serving of ice cream (1/2 cup) may contain about 170,000 micrograms of polysorbate 80”. That’s 170 milligrams of polysorbate 80 in one ice-cream serving. On the other hand, the vitamin K product presented by Vaughan contains 10 milligrams of Polysorbate 80. Therefore, children are much more exposed to polysorbate 80 when eating ice cream.
The European Medicines Agency (EMA) considers that “short term exposure of [polysorbate 80] < 10 mg/kg per day is safe even in infants and neonates”. A one-dose injection of vitamin K containing 10 milligrams of polysorbate 80 into a newborn weighing 3 kilograms—the average weight at birth—is then equivalent to a dose of 3.3 milligram per kilogram of body weight. So, the amount of polysorbate 80 received by newborns through the vitamin K injection is within the safe range recommended by the EMA.
Vaughan’s claim that polysorbate 80 is prohibited in a lot of countries is also inaccurate. As mentioned above, polysorbate 80 is authorized in Europe. It is also an ingredient in some vaccines in Canada and Australia.
Finally, there’s no supporting evidence that polysorbate 80 is related to human infertility. Only one study, from 1992, reported impaired reproductive organs in rats exposed to polysorbate 80 at birth.
However, the relevance of these results to humans is doubtful. The researchers administered 0.1 milliliter of a 1% Tween 80 solution in each rat, at days four, five, six and seven after birth. A 1% solution means that 0.1mL of it contains 0.001mL of Tween 80. Tween 80 has a density of 1.07g/mL. So, 0.001mL of a 1% solution contains 0.00107g of Tween 80, that is 1.07mg. This means that the rats received 1.07mg of polysorbate 80 at each injection. Given that the average weight at birth of a rat is around 6 grams. These rats therefore received a dose of about 180 milligrams per kilogram of body weight, repeated four times, or about 720 milligrams per kilogram of body weight in total.
By comparing this with the amount of polysorbate 80 in the vitamin K injection—10mg only once—it becomes clear that the dose of polysorbate 80 used in the rats is about 70 times higher than the amount received by newborns through the vitamin K injection.
In summary, the polysorbate 80 at concentrations used in vitamin K shots is known to be safe, and well below the amount present in commercially available food like ice cream. No scientific data indicates that the amount of polysorbate 80 in vitamin K shots would negatively affect human immunity or fertility either. Furthermore, vitamin K deficiency can be fatal to newborns and is effectively prevented by vitamin K shots. Therefore, these injections aren’t only safe, but also crucial to prevent avoidable child deaths.
- 1 – Rogers et al. (2023) Neonatologists and vitamin K hesitancy. Journal of Perinatology.
- 2 – Gajdová et al. (1992) Delayed effects of neonatal exposure to Tween 80 on female reproductive organs in rats. Food and Chemical Toxicology.
- 3 – Ghasemi et al. (2021) The laboratory rat: Age and body weight matter. EXCLI Journal