Nutrients (part 3): Vitamins, Water, Fibre & Balanced diet

1. Vitamins Vitamins Vitamins

2. Vitamins • Organic compounds • Not built in a definite pattern • Not energy providing • Required in small amts (for normal growth & development) • Diff. vitamins found in diff. foods (varied diet → ensure we get most of our vitamins)

3. Vitamins • Amt. required varies with age • Water soluble vs fat soluble vitamins Cannot be stored in body → → need to be need to be supplied in diet supplied in diet Can be stored in fats of the body • Symptoms (characteristic signs) appear if vitamin deficient (mild/severe) • Mild deficiency (symptoms: person irritable/feels run-down)

4. Vitamins A (Pg. 69 Biology Textbook) Functions: 1. formation of retina 2. Maintaining healthy epithelial tissues Sources: 1. Dairy products 2. Fish liver-oils 3. Green leafy vegetables

5. Vitamin A deficiency

6. Vit. B complex Function: • Important co-enzymes in cellular respiration (several) Sources: 1. Yeast 2. Liver 3. Bran

7. Vit. B deficiency 1. Anemia is a condition where RBCs are not providing adequate oxygen to body tissues 2. Many types and causes of anemia 3. Pernicious anemia is caused by a lack of intrinsic factor, a substance needed to absorb vitamin B12 from the gastrointestinal tract 4. Vitamin B12 is necessary for the formation of red blood cells - large, dense, oversized, red blood cells (RBCs) - occur when there is a deficiency of vitamin B-12.

8. Vit. B deficiency

9. Vit. C • Function(s): • Needed for formation of intercellular substances (btw cells; hold cells together) • Necessary for maintaining healthy epithelial tissues Sources: 1. Fresh citrus fruits (oranges, lemons) + fruits (bananas, guava, papaya, tomatoes) 2. Fresh green vegetables 3. Fruits juices (blackcurrent + rose hip syrups) Note: Easily destroyed by heat; excess is excreted by body Water soluble vitamin

10. Scurvy • caused by a dietary lack of vitamin C (ascorbic acid) • Ascorbic acid is important in the formation of collagen (an element of normal tissues), and any deficiency interferes with normal tissue synthesis

11. Scurvy "warning signs" Gingival Hemorrhage (swollen and bleeding gums with loosened teeth) Corkscrew Hair Periungual Hemorrhage (soreness and stiffness of the joints)

12. Vit. D • Fat-soluble vitamin Function: • Promotes absorption of calcium + phosphorous (from intestine) → form teeth + bones Sources: • Fish liver oils (cod & halibut), eggs, yolk, milk & margarine • Ultraviolet rays in sunlight (ergosterol in skin → Vitamin D)

13. Rickets Knock knee deformity (genu valgum) Bowleg deformity (genu varum) Wrist enlargement Ankle enlargement - Poor teeth and bone formation - Childrens’ bones are soft; pliable; bent under body weight

14. Excess Vit. D • Demineralisation of bones → multiple fractures → widespread calcification of soft tissues Calcification: • 99% of calcium entering the body is deposited in bones and teeth • Remaining 1% of calcium is dissolved in the blood • When a disorder affects the balance between calcium and other minerals or hormones, calcium can be deposited in other parts of the body, such as arteries, kidneys, lungs, and brain. • Calcium deposits in these parts of the body can cause problems with the function of these organs.

15. Water Water Water

16. Water • Essential component of protoplasm (very impt.) Functions: 1. Medium in which various chemical rxns take place 2. Transporting agent for - digested food substances (intestines → other parts of body) - excretory products (tissue cells → excretory organs) - hormones (from place of origin → regions of body that require them) 3. Major/essential component of - lubricant found in joints - digestive juices - blood

17. Water requirements Depends on: 1. Activity of person (active?) 2. Environmental conditions (hot & dry → more water required) 3. Suffering from disease? (e.g. diabetes → water lost through urine)

18. Minerals Minerals Minerals

19. Minerals • Inorganic salts • Do not provide energy • Indispensable to bodily functions • Obtained from animals or plants • Requirements vary for diff. minerals (K, Na, Cl, P, Fe → large amts.) • Trace elements (minerals required in minute amts.) e.g. I, Zn, Mn

20. Minerals • Refer to pg. 71 of textbook

21. Dietary Dietary fibre fibre Dietary fibre (roughage) (roughage) (roughage)

22. Dietary fibre Refers to indigestible fibrous materials present in diet e.g. cellulose Functions: 1. Provides bulk to intestinal contents 2. Helps peristalsis (wavelike, muscular contractions of walls of digestive tract → propels food to move along digestive canal) → lack will cause constipation Sources: • Fresh fruit • Vegetables • Bran • Cereals • Wholemeal bread •

23. Balanced diet Balanced diet Balanced diet

24. Balanced diet Definition: Contains the right amount of carbohydrates, fats, vitamins, minerals, water and roughage to meet the daily requirements of the body - Varies with lifestyle, activities and age

25. Basal metabolic rate Definition: Amount of energy required to carry on vital life processes of the body when it is in complete rest Affected by: 1. Climate (cold → lose more heat → more energy to maintain body temp.) 2. Body size (big/small; big → more energy for basal metablism)) 3. Age (young/old; young → more energy needed for growth) 4. Sex (male/female; males have higher heat production because they have less amt. of fatty tissue) 5. Health of individual (thyroxine levels determined by activity of thyroid gland; more thyroxine → high basal metabolic rate) 6. Occupation (active → more energy → higher basal metabolic rate)

26. Energy balance • Ideally there should be a balance between energy intake and expenditure • If energy intake high; expenditure low → body gains weight

27. Losing weight • Reduced intake of fats and carbohydrates (not other food nutrients e.g. protein) • High protein intake discouraged → excessive amt. of nitrogen → removed by liver (urea) → excreted by kidneys in urine (overwork liver and kidneys → damage)