The vitamin K shot given to newborns thickens the blood and stops stem cells from circulating.
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The real story
Newborns start life low in vitamin K because very little crosses the placenta and their gut bacteria are not yet making much of it. That puts them at risk of a dangerous condition called vitamin K deficiency bleeding, and the birth shot greatly reduces that risk. There is no evidence it changes how thick the blood is or stops stem cells or nutrients from circulating.
The fact-checker's verdict: “Inaccurate”. Our label never goes further than theirs.
If a post blames a routine newborn treatment, look up what problem the treatment prevents; that part is usually missing from the post.
The receipts
Vitamin K shot doesn't stop stem cells from circulating or change blood thickness ↗
Science Feedback · 2026-10-13
