KINE 2P20 Lecture Notes - Lecture 9: Nicotinamide, Chylomicron, Hypertension
9 May 2018
School
Department
Course
Professor
Nutrition 2P20
CHPT 8
Vitamins
- Organic compounds essential in the diet to promote growth and health
- Water soluble vitamins: B(s) & C
- Fat soluble vitamins: A, D, E, K
Fortification in common foods
- Salt (iodine), milk (Vit. D), Grains (thiamine, riboflavin, niacin, iron, folic acid)
Vitamins in the digestive tract
- Digestive enzymes release vitamins from food in the SI
- Water soluble – absorbed directly into blood to go to liver
- Fat-soluble – incorporated into micelles and transported by chylomicrons via lymphatic
system
Bioavailability of Vitamins
- ~40-90% of vitamins are absorbed
- Fat-soluble require fat to be absorbed
- Water-soluble may require transport molecules and/or membrane proteins
- Some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must
be converted to active forms by the body
Thiamin (B1)
- Coenzyme in energy metabolism
- Needed for neurotransmitter production (acetylcholine), ribose (RNA)
- Deficiency
▪ Beriberi – lethargy, fatigue, neurological symptoms
▪ More common in poorer countries
▪ CV problems, congestive heart failure, weakness, irritability, alcoholism
can exacerbate it
- DRI and Toxicity
▪ RDA men (19-50) 1.2mg/d
▪ RDA women (19-50) 1.1mg/d
▪ No known toxicity
Riboflavin (B2)
- Coenzyme in energy metabolism redox reactions
▪ FMN – Flavin mononucleotide
▪ FAD – Flavin adenine dinucleotide
- Easily destroyed by heat/ exposure to light
- Deficiency
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Document Summary
Organic compounds essential in the diet to promote growth and health. Fat soluble vitamins: a, d, e, k. D), grains (thiamine, riboflavin, niacin, iron, folic acid) Digestive enzymes release vitamins from food in the si. Water soluble absorbed directly into blood to go to liver. Fat-soluble incorporated into micelles and transported by chylomicrons via lymphatic system. Water-soluble may require transport molecules and/or membrane proteins. Some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must be converted to active forms by the body. Needed for neurotransmitter production (acetylcholine), ribose (rna) Deficiency: beriberi lethargy, fatigue, neurological symptoms, more common in poorer countries, cv problems, congestive heart failure, weakness, irritability, alcoholism. Dri and toxicity can exacerbate it: rda men (19-50) 1. 2mg/d, rda women (19-50) 1. 1mg/d, no known toxicity. Coenzyme in energy metabolism redox reactions: fmn flavin mononucleotide, fad flavin adenine dinucleotide. Easily destroyed by heat/ exposure to light.
