ابتسام الشدي Ebtesam Al- sheddi

1. ابتسام الشديEbtesam Al-sheddi • Email: ebtesam.saad@yahoo.com • Site: faculty.ksu.edu.sa/10252

2. 413 PHG 50% by Dr.Ebtesam S. Al-Sheddi-15 marks midterm exam 20 marks final exam 50% by Dr. Areej Al-Taweel -15 marks midterm exam -20 marks final exam Lab : 30 marks: - Practical exam

3. Course description • The course will cover the following subjects: • Vitamins • Minerals • Allergens • Biologics

4. By the end of the course • You should be able to know: • What are the Water soluble vitamins • What are the Fat soluble vitamins • The recommended dose, function, deficiency and the toxicity of each vitamin. • What are the micro and macro-minerals • The recommended dose, function, deficiency and the toxicity of each mineral. • What are allergens and the different types. • What are biologics and the different types

5. Vitaminslecture 1 Presented By: Ebtesam Al-Sheddi

6. When substance is defined as vitamin Three criteria: 1- Required in small amounts 2- Must be organic chemical. 3- There is specific set of symptoms or specific diseases associated with a deficiency of each vitamin. Could be called cofactors or catalysts or others depending on the functions.

7. 13 Vitamins for good health: 2 groups Water soluble vitamins B group: B1 thiamin B2 riboflavin B3 niacin B5 pantothenic acid B6 pyridoxine B7 bitoin B9 folic acid B 12 cyanocobalmin Vitamin C ascorbic acid Fat soluble vitamins Vitamin A Vitamin D Vitamin E Vitamin K

8. Fat versus water solublevitamins Fat-soluble vitamins • Dissolve in fat • Require bile acids to be dissolved and then absorbed. • Can be stored in body: liver, adipose tissue. • Toxicity is possible. Water-soluble vitamins • Dissolve in water. • Easily absorbed. • Not stored in large quantities. • Execrated via urine. • Generally non-toxic.

9. Fat soluble vitaminsvitamin A Generally called retinol. It is a group of compounds with the biological activity of retinol. These compounds include: Provitamin A and Preformed vitamin A

10. Provitamin A Preformed vitamin A Animal source Called retinoids: Retinol (key player) and retinyl ester. Consist of 4 isoprene units (C20) Plant source Called carotenoids: α-carotene, β-carotene and β-cryptoxanthin. Consist of 8 isoprene units (C40)

11. Retinoids and carotenoids are precursors for the biosynthesis of 2 essential metabolites of vitamin A: • 11-cis-retinal and all-trans-retinoic acid.

12. All trans-retinoic acid Vitamin A functions 11- cis- retinal Required for night and color vision. Formed in retina. Component of visual pigments (rhodospin rods) that present in retina. The most bioactive form. Required for: regulation of embryonic development and growth and reproduction. maintenance of epithelial tissue and repair of body tissues. proper function of immune system • Carotenoids • Serve as antioxidants • .

13. Source: • Preformed: liver, milk, ready eat cereal, margarine and egg. • Provitamin: carrot, cantaloupe, sweet potato and spinach. • Recommended daily allowance (RDA) = 4000 – 5000 IU (International Units). • 1 IU from 0.3 µg of retinol or 0.6 µg of β-carotene

14. Vitamin A deficiency • More obvious deficiency symptoms than other vitamins • Night blindness • Leading cause of blindness in third world countries • Cell keratinization • Dry skin (treatment and pregnancy?) • Xerophthalmia (dryness of cornea & conjunctiva) • Reproductive failure • Abnormal skeletal development/maintenance • Immune dysfunction • Respiratory infection.

15. Hypervitaminosis A • Skeletal malformations, spontaneous fractures, internal hemorrhages • Overconsumption of beta carotene from food sources may cause skin to turn yellow but is not harmful • Birth defects and miscarriage • Decalcification, joint pain, fragility • Dry itchy skin (caution about acne treatments) • Hair loss • Liver damage

16. Fat soluble vitaminsvitamin D • The two major forms are • vitamin D2 or ergocalciferol, plant version vitamin D3 or cholecalciferol, animal version • (Calciferol)

17. Vitamin D2 (made from ergosterol) • Vitamin D3 is made in the skin when 7-dehydrocholesterol reacts with ultraviolet light. • Vitamin D3 is biologically inert, must undergo two hydroxylation reactions to be activated in the body. • Calcitriol (1,25-dihydroxycholecalciferol) is the active form of vitamin D

20. Vitamin D - Functions • Regulation of bone health, calcium, and phosphorus • Regulation of muscle composition and muscle function • Prevention of cancer • Regulation of immune system • Regulation of insulin and blood sugar • Regulation of blood pressure and cardiovascular health

21. Sourses • Vitamin D is naturally produced by the human body when exposed to direct sunlight. • Expose hands, face, arms 2-3 x/week for 5-10 minutes each time. • Milk, yogurt, margarine, cereals, bread, pastries fortified with vitamin D2 and/or vitamin D3. • Egg cod liver oil and salmon • Adequate Intake (AI) for VitaminD • 5 ug/d (200 IU/day) for adults under age 51 • 10-15 ug/day (400 - 600 IU/day) for older adults –May need combination of fortified foods

22. Vitamin D deficiency • impaired bone mineralization and leads to bone softening diseases, rickets in children and osteomalacia in adults, and possibly contributes to osteoporosis.

23. Hypervitaminosis D • Hypercalcemia • High blood pressure • Anorexia, nausea and vomiting • These symptoms are often followed by polyuria, polydepsia, weakness, nervousness, pruritus, and eventually renal failure

24. Fat soluble vitaminsVitamin E • The term vitamin E refers to a family of eight related compounds, the tocopherols and the tocotrienols • The four major forms of vitamin E are designated a, b, d, g, that have varying levels of biological activity • Alpha- (or α-) tocopherol is the most active form • Termed an antioxidant

26. Vitamin E • Protects cell membranes and other fat-soluble parts of the body (LDL cholesterol) from oxidation • May reduce the risk of heart disease • May also discourage development of some types of cancer • Promotes normal growth and development • Promotes normal red blood cell formation • Acts as anti-blood clotting agent • Plays some role in the body’s ability to process glucose • Also been known to aid the process of wound healing

27. Sources • Plant sources • Cereal grains • wheat germ oil, almonds, sunflower seeds, sunflower oil, safflower oil, hazelnuts, peanut butter, peanuts, corn oil, spinach, broccoli, soybean oil, kiwi and mango. Vegetable and seed oils • Little in animal sources • Beef fed high levels of vitamin E right before slaughter to improve shelf life can be source • The RDA (recommended daily allowance) for vitamin E is 15 mg of d-alpha-tocopherol for adult men and women (1 mg of d-alpha-tocopherol is equal to 1.5 IU, so the RDA is equal to 22.5 IU).

28. Vitamin E Toxicity • Wide range of safe intake compared to other fat soluble vitamins (toxicity rare) • Extreme high doses (50- to 100-fold above recommended intakes) may affect the blood clotting effects of vitamin K and may lead to increased risk of hemorrhage

29. Fat soluble vitaminsVitamin K • K1, phylloquinone • Chloroplasts in plants • K2, menaquinone • Bacterial synthesis • K3, menadione • Synthetic, water soluble form • Complexed to improve stability Vitamin K2

30. Physiological Effects of Vitamin K • Vitamin K serves as an essential cofactor for a carboxylase that catalyzes carboxylation of glutamic acid residues on vitamin K-dependent proteins. These proteins are involved in: 1) Coagulation2) Bone Mineralization3) Cell growth

31. Coagulation • The transformation of liquid blood into a solid gel • Stops blood flow in the damaged area • Fibrin is the final protein which produces a meshwork to trap RBC and other cells

32. Vitamin K Dependent Coagulation • Certain clotting factors/proteins require calcium to bind for activation • Calcium can only bind after gamma carboxylation of specific glutamic acid residues in these proteins • The reduced form of vitamin K2 (vitamin KH2) acts as a cofactor for this carboxylation reaction. • These proteins are known as “Vitamin K dependent” proteins

33. Vitamin K Dependent Proteins • factor II (prothrombin) • factor VII (proconvertin) • factor IX (thromboplastin component) • factor X (Stuart factor) • protein C & protein S • Protein Z

34. Clotting Cascade

35. Vitamin K Cycle Vitamin KH2 Glutamic Acid Reductase Vitamin K Vitamin K Dependent Carboxylase Warfarin Inhibits Epoxide Reductase Gamma Carboxy Glutamic Acid Vitamin K Epoxide

36. Dietary Sources • The best food sources of vitamin K are green leafy vegetables. • Milk and liver. • Daily requirement:

37. Vitamin K Deficiency Results in impaired blood clotting and, potentially, bleeding. Vitamin K deficiency can result from: • a lack of vitamin k in the diet • disorders that reduce fat absorption • Taking certain drugs, including anticonvulsants and some antibiotics • Use of coumarin anticoagulants • Salicylates • Large doses of vitamin E • Hepatic insufficiency

38. Symptoms of Vitamin K Deficiency • Bruising from bleeding into the skin • Nosebleeds • Bleeding gums • Bleeding in stomach • Blood in urine • Blood in stool • Tarry black stool • Extremely heavy menstrual bleeding • In infants, may result in intracranial hemorrhage

39. Vitamin K Deficiency in Infants Newborns are prone to vitamin K deficiency because… • Vitamin K and lipids are not easily transported across the placental barrier • Prothrombin synthesis in the liver is an immature process in newborns, especially when premature. • The neonatal gut is sterile, lacking the bacteria that is necessary in menaquinone synthesis. • Breast milk is not a good source of vitamin K Results in a hemorrhagic disease called vitamin K deficiency bleeding (VKDB) This disease is associated with breastfeeding, maladsorption of lipids, or liver disorders.

40. Vitamin K - Toxicity • Not common except with over-supplementation • Phylloquinone and menaquinone are relatively nontoxic • Jaundice; brain damage • Menadione toxic to skin and respiratory tract in high doses