Vitamin A (Retinol)

Vitamin A (Retinol) is a fat-soluble vitamin essential for vision (especially night vision), immune function, cell growth, and reproduction. Deficiency can lead to blindness and increased susceptibility to infections. Excess intake (especially of preformed retinol from supplements or liver) can be toxic, causing liver damage and birth defects. Serum retinol levels are regulated and may not drop until liver stores are severely depleted.