all-trans-Retinol-d5 is a labeled analog of all-trans-Retinol (R252000), which occurs preformed only in animals; metabolized from carotenoids, such β-carotene, in the intestinal mucosa. Dietary sources include liver, milk, butter, cheese, eggs and fish liver oils or as carotenois from fruits and vegetables. Stored primarily in the liver in esterified form; transported in the blood by retinol binding protein (RBP). Nutritional factor.
