Looked up what cholecalciferol was made of and here is what I found.

Flesh of fatty fish & fish liver oils. Smaller amounts are found in egg yolks, cheese, and beef liver. Also found in lanolin washed from lambs' wool.

Just because it's poison to rats doesn't mean it's poison to humans.

Another example is Borax. I take borax at times for what I feel is health benefits. It is poison to ants. Again, just because it kills ants doesn't mean it kills humans.

I'm NOT a doctor, scientist or chemist. I search things and take IF I feel it is good for ME.

Thank you for sharing this video however because it does cause me to dig deeper into what I take.