NUTR1023 Lecture Notes - Lecture 5: Retinol, Flavin Adenine Dinucleotide, Complications Of Pregnancy
NUTR1023 Health and Fitness Through Diet and Exercise
Summer Semester 2017
Module 5 – Micronutrients
Objectives
At the end of this module students will be able to do the following:
• Describe the functions of selected vitamins and minerals in the body
• Describe how selected vitamins and minerals are absorbed
• List symptoms and conditions associated with deficiency and toxicity of selected
vitamins and minerals
• List some rich food sources of specific vitamins and minerals
Vitamins
➢ Organic compounds occurring in small amounts in food
➢ Vitamins cannot be synthesised in the body (with some exceptions)
➢ Some vitamins are often available from foods in inactive forms known as precursors
or provitamins
➢ Fat soluble – A, D, E, K
o Ofte stored i the odys tissue
➢ Water soluble – B vitamins, C
o Dispersed in the body without being stored
➢ Thiamin
o B vitamin
o Energy metabolism
o Transmission of nerve impulses
o Thiamine deficiency is common when energy intake is low and in alcoholics
o Beriberi – damage to the nervous system, heart and other muscles; muscle
wasting (dry) or oedema (wet)
o Wernicke – Korsakoff syndrome – a combination of cerebral beriberi and
psychosis
o Thiamin toxicity is rare
o Good food sources – pork, vegemite and whole grains
➢ Riboflavin
o B Vitamin
o Coenzyme in reactions of energy metabolism
o Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)
o Deficiency results in inflammation of the membranes of the mouth, skin,
eyes, GI tract
o Toxicity extremely rare
o Good food sources – milk, wholegrains, dark green vegetables
➢ Niacin
o B vitamin
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o Coenzymes in reaction of energy metabolism
o The coenzyme forms of niacin are nicotinamide adenine dinucleotide (NAD)
and nicotinamide adenine dinucleotide phosphate (NADP)
o Niacin can be made from tryptophan
o 60mg of dietary tryptophan – 1mg niacin
o Recommended intakes are provided in niacin equivalents (NE)
o Deficiency – pellagra
▪ Diarrhoea, dermatitis, dementia
o Toxicity possible after supplementation -niacin flush
o Good food sources – meat, poultry, whole grains, mushrooms, tomatoes
➢ Folate
o B vitamin
o Also known as folic acid
o Functions with B12 in DNA synthesis and conversion of homocysteine to
methionine
o Folate intake associated with neural tube defects
o Folate deficiency results in megaloblastic anaemia
o Green leafy vegetable, fruits legumes
o Most bread now fortified with folate
➢ Vitamin B12
o Vitamin B12 and folate are activated by transferring a methyl group
o Similar functions as folate
o Deficiency associated with lack of intrinsic factor
o Vegans at risk of deficiency
o Good food sources – meat, fish, poultry, eggs, milk, cheese
➢ Vitamin C
o Water soluble
o Collagen synthesis – connective tissue
o Synthesis of carnitine
o Synthesis of hormones and neurotransmitters
o General anti oxidant function
o Iron absorption
o Immune function
o Deficiency – scurvy
▪ Poor wound healing
▪ Bleeding gums
▪ Fatigue
o Good food sources – citrus fruits, capsicum, berries, green leafy vegetables
➢ Vitamin A
o Retinol – supports reproduction; major transport and storage form of vitamin
A
o Retinal – vision, conversion of retinol to retinoic acid
o Retinoic acid – regulates cell differentiation, growth and embryonic
development
o Foods derived from animals provide retinyl esters that are converted to
retinol
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find more resources at oneclass.com
o Foods of plant origins provide carotenoids, some of which have vitamin A –
namely beta - carotene which can be split to form retinol in the liver and
intestine
o Deficiency
▪ Night blindness
▪ Xeropthalmia
▪ Keratinisation of skin
o Toxicity
▪ Birth defects
o 1μg retinol equivalent = 6 μg eta-carotene
o Good food sources – red, orange, yellow, dark green fruits and vegetables,
liver, eggs
➢ Vitamin D
o Regulates blood calcium levels
o Enhances phosphorus and calcium absorption
o Bone mineralisation
o Deficiency risk increased with lack of sun exposure
o Rickets, osteomalacia
o Good food sources – milk, butter, egg yolks, beef, liver
➢ Vitamin E
o Lipid soluble antioxidant
o Prevents oxidation of fats in the body
o Possibly reduces risk of CV disease
o Deficiency and toxicity are very rare
o Good food sources – margarine, vegetable oil, egg yolk
➢ Vitamin K
o Synthesised by bacteria in the gut
o Involved in blood clotting and synthesis of bone proteins
o Deficiency rare – possible if gut bacteria destroyed
o Anticoagulant drugs interfere with vitamin K activity
o Good food sources - Green leafy vegetable, liver
➢ Calcium
o Bone and teeth mineral
o Muscle contraction
o Blood clotting
o Enzyme activation
o Blood levels tightly regulated by PTH, calcitonin and Vitamin D
o Deficiency
▪ Osteoporosis
▪ Poor growth in children
o Toxicity
▪ Impaired absorption of other minerals
▪ Increased kidney stone formation
o Good food sources – dairy products, fish with edible bones, almonds, green
vegetables
➢ Sodium
o Muscle contraction
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Nutr1023 health and fitness through diet and exercise. At the end of this module students will be able to do the following: describe the functions of selected vitamins and minerals in the body, describe how selected vitamins and minerals are absorbed. List symptoms and conditions associated with deficiency and toxicity of selected vitamins and minerals. List some rich food sources of specific vitamins and minerals. Organic compounds occurring in small amounts in food. Vitamins cannot be synthesised in the body (with some exceptions) Some vitamins are often available from foods in inactive forms known as precursors or provitamins. Fat soluble a, d, e, k: ofte(cid:374) stored i(cid:374) the (cid:271)ody(cid:859)s tissue. Water soluble b vitamins, c: dispersed in the body without being stored. Vitamin c: water soluble, collagen synthesis connective tissue, synthesis of carnitine, synthesis of hormones and neurotransmitters, general anti oxidant function.
