Honestly, it was pretty hard for me to find a source which has made me a little skeptical of my own statements.
I was able to find two case studies in which patients with liver damage that caused them to have low levels of vitamin A exhibited night blindness. Both were treated for vitamin A deficiency and saw symptoms improve.
The strongest evidence of my original claim is the fact that one of the patients had otherwise healthy eyes and vision, only having extreme trouble seeing at night. After receiving treatment for vitamin A deficiency, her night vision improved. This suggests that dark adaptation is dependent on vitamin A in the blood which is regulated by the liver.
However, I’m now somewhat skeptical and curious myself considering these two studies were almost all I could find on this topic. If I have more time I’ll try digging deeper. For now though, I’ve edited my comment with links to the studies.
Honestly, it was pretty hard for me to find a source which has made me a little skeptical of my own statements.
I was able to find two case studies in which patients with liver damage that caused them to have low levels of vitamin A exhibited night blindness. Both were treated for vitamin A deficiency and saw symptoms improve.
The strongest evidence of my original claim is the fact that one of the patients had otherwise healthy eyes and vision, only having extreme trouble seeing at night. After receiving treatment for vitamin A deficiency, her night vision improved. This suggests that dark adaptation is dependent on vitamin A in the blood which is regulated by the liver.
However, I’m now somewhat skeptical and curious myself considering these two studies were almost all I could find on this topic. If I have more time I’ll try digging deeper. For now though, I’ve edited my comment with links to the studies.