NUTR 120 Lecture Notes - Lecture 21: Muscle Contraction, Teratology, Isotretinoin
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Retinoids- animal sources (retinol- least oxidized retinal retanoic acid- most. Rda: women- 700 mcg rae (retinol activity equivalents, men- 900 mcg rae (retinol activity equivalents) Beef liver (liver is a good source of everything) Vision- visual cycle (retinal: role of retinal in the visual cycle (figure 9. 4 in textbook): May cause difficulty adapting to dim light after exposure to bright light. Epithelial cell function- skin, respiratory tract, gi tract, corneal epithelia, etc: keratinization- drying of the epithelial cells (drying of the eye, xerophthalmia- deficiency of vitamin a. Scarring in deeper layers (loss of sight- can not be reversed at this point) Reproduction: women deficient in vitamin a can experience in fetal reabsorption, men deficient in vitamin a have decreased sperm formation. Must differentiate between: beta-carotene in foods vs supplements. In studies (1997) it was found that people who were taking beta- carotene had a 17% higher chance of developing cancer: retinoids (food or supplements)