“This Vitamin Raises Stroke Risk Overnight” — What’s the Truth?
This headline appears to come from a viral 2025 video claiming that vitamins such as D, E, B6, A and niacin can unexpectedly increase stroke risk in older adults.
B
Before It’s News
+1
The claim that a vitamin suddenly raises your stroke risk overnight—especially simply because you take it at night—is not supported by good evidence.
What is actually known?
Vitamin D: Excessive vitamin D supplementation can cause dangerously high calcium levels, but that is a toxicity problem—not evidence that taking normal vitamin D at night causes a stroke.
Vitamin E: High-dose vitamin E can increase bleeding risk, particularly with anticoagulant medicines such as warfarin. This is a legitimate concern, but it doesn’t mean ordinary dietary vitamin E causes strokes.
Vitamin B6: Very high or prolonged doses can cause nerve damage. Evidence does not establish that normal B6 intake suddenly increases stroke risk. NIH notes that trials have generally not shown B6 supplementation to increase cardiovascular or stroke risk.
O
Office of Dietary Supplements
Vitamin B12/folate/B6: Interestingly, research has generally investigated these vitamins for reducing stroke risk by lowering homocysteine, although results vary by population and formulation.
P
PubMed Central (PMC)
+1
Vitamin A: Excessive preformed vitamin A can be toxic and cause serious problems, but the viral claim that taking it at night causes a sudden stroke isn’t established.
The important lesson
“Natural” doesn’t automatically mean harmless, and more isn’t necessarily better. High-dose supplements can interact with medicines or cause toxicity, particularly in older adults or people with kidney or liver problems.
But don’t stop a prescribed vitamin or supplement solely because of this headline. If you tell me which vitamin you’re taking, the dose, your age, and any medicines you take, I can check whether that particular combination has a meaningful stroke or bleeding risk.
B
O
P
Sources
