Presentation of vitamins ( Nutrition ) ppt

Vitamins

1. FAT SOLUBLE VITAMINS

2. Fat soluble vitamins are soluble in fat and are absorbed by intestine, with the help of dietary fat. These include vitamins A, D, E and K

3. VITAMIN A Vitamin A refers to a group of three compounds, collectively called retinoids . These include retinol (vitamin A alcohol), retinal (vitamin A aldehyde or retinaldehyde) and retinoic acid (vitamin A acid). In addition, plants contain a group of compounds called carotenoids . They yield retinoids, when metabolized in the body and, are called as precursors of vitamin A.

4. Recommended daily allowances .Average daily requirement of vitamin A for adults is 600 ug. 950 ug during pregnancy and lactation. Children 300 to 600microgram

5. Dietary sources Animal foods, liver, cod liver oil, egg yolk and milk, are rich sources of retinoids. Plant sources • Dark green and yellow-orange vegetables, such as carrots, spinach and broccoli, and orange colored fruits, like peaches, apricots and mango, are good sources of carotenoids.

6. Functions Vitamin A is essential for normal structure and functions of the skin and mucous membranes, such as eyes, lungs and digestive system. , vital for vision, embryonic development, growth and cellular differentiation, and immune system. Retinal is essential for night and color vision.

7. Retinol is required in reproduction and bone health.• Retinoic acid is important for cellgrowth Carotenoids function as antioxidants and prevent damage by f ree radicals. to prevent damage from chemical carcinogens and lower the risk cancer.

8. synthesis, metabolism, st orage and excretion Retinoids and carotenoids incorporates with lipids, and passive absorption occurs into the mucosal cells of the small intestine . They are incorporated into chylomicrons for transport into the lymph and, eventually, the bloodstream

9. The liver plays an important role in vitamin A transport and storage. • Retinol is oxidized to retinal and then to retinoic acid, or conjugated into retinyl glucuronide or retinyl phosphate. Oxidized forms of vitamin A are excreted in the urine while intact forms are excreted in the bile and feces.

10. Retinoids and caratinoids +lipids. passive transport small intestine. Lymph. blood portal circulation. liver oxidation. Retinal. retinoic acid excess of retinoids conjugated retinyl glucuronide and retinyl phosphate. excreted in urine and in fecas

11. Deficiency diseases Vitamin A deficiency causes night blindness (impaired adaptation to lowintensity light), which can subsequently lead to xerophthalmia (dryness of the conjunctiva and cornea) and blindness , Vitamin A deficiency also affects production of sperm, in men. Women can become infertile, possibly, due to disruption in the production of the reproductive tract secretions. . Vitamin A deficiency also reduces the number of T-lymphocytes.

12. Causes bacterial, parasitic and viral infections. Children with lack of vitamin A are at higher risk of diarrhea, respiratory tract infections and measles. Vitamin A deficiency also retards growth and development, and leads to bone deformities.

13. Hypervitaminosis Vitamin A toxicity, with megadoses of supplements, can cause symptoms, such as fatigue, vomiting, abdominal pain, bone and joint pain, loss of appetite, skin disorders, headache and blurred vision. Excess doses of vitamin A, prior to conception and in the first few months of pregnancy, can cause spontaneous abortions. Hypervitaminosis A is teratogenic , and can lead to birth defects including cleft palate, heart abnormalities and brain malfunctions. .

14. VITAMIN D Vitamin D is a sterol (steroid alcohol), also called as sunshine vitamin. exhibit antirachitic properties, Vitamin D2 (ergocalciferol) found in plant foods, Vitamin D3 (cholecalciferol) found in animal foods synthesized in the skin . Vitamin D acts as a precursor to the hormone, calcitriol ( 1,25-dihydroxycholecalciferol ), involved in calcium synthesis , that is essential for bone mineralization and neuromuscular functions.

15. Recommended daily allowances breast fed infants, who receive little exposure to sunlight, need 5 mg (200 IU) of vitamin D per day (1 mg = 40 IU) . For elder people recommended daily intake is 10 mg ( 400 IU. )

16. Dietary sources Most of the vitamin D, is obtained through the action of sunlight on skin . Major dietary sources cod liver oil, fish oil, egg yolk and liver. fortified milk and foods.

17. functions Primary role of vitamin D is to regulate blood calcium level . Calcitriol , the hormone synthesized from vitamin D, along with parathyroid hormone and calcitonin , regulates blood calcium levels through its action on bone, kidneys and small intestine , vitamin D inhibit cell proliferation and enhance cell differentiation. .

18. Absorption, Synthesis, Metabolism, Storage and Excretion Dietary vitamin D is incorporated with lipids ,as chylomicrons absorbed in the intestine, by passive diffusion enters the lymphatic system and then , enters plasma, blood it is delivered to the liver by chylomicron to the specific carrier vitamin D-binding protein (DBP).

19. Vitamin D from food.+lipids Passive diffusion. Absorbed in small intestine Chylomicroms with vitamin D. Lymph. Blood. Portal circulation. Liver. 25 hydroxyvitamin D3(25- hydroxycalceferol)/. Lymph blood Vitamins D binding proteins stored in the peripheral tissues 25 hydroxyholecalciferol. acted upon by the alpha _1_ cholecalciferol. 1,25-dihydroxycolcalceferol (calcitriol). Excess is excreted in urine

20. .Vitamin D is transported by DBP, delivered to the peripheral tissues Vitamin D, is also synthesized and stored in the skin from 7-dehydrocholesterol (provitamin D) .In the liver it is converted to 25-hydroxyvitamin D3 (25hydroxycholecalciferol). Stored vitamin D is . acted upon , by the enzyme alpha -1hydroxylase in the kidney, it is converted to calcitriol [1, 25-dihydro colcalceferol) the most active form of the vitamin.

21. Deficiency disorders Prolonged deficiency of vitamin D, in children leads to rickets . bone pain, poor growth and deformities of the skeleton, bowed legs, curvature of the spine, and thickening of the ankles, wrists and knees . Ends of the long bones become soft and bulky, characteristic of bowed-legs and knock-knees. extreme stunting of growth

22. In adults, . Deficiency can lead to osteomalacia , also referred to as adult rickets. symptoms include increased bone degeneration , leading to pain bones and muscle weakness.

23. Hypervitaminosis Excessive dietary vitamin D intake lead to hypercalcemia ( high calcium level in the blood) . Hypercalcemia can result in deposition of excess calcium in soft tissues and heart and kidney damage . affect nervous system, causing severe depression GIT disturbances (nausea, vomiting and loss of appetite) .

24. VITAMIN E Vitamin E refers to a group of several lipid soluble compounds synthesized by plants, such as tocopherols and tocotrienols.

25. Recommended daily allowances : Average daily requirement of a tocopherol, for adults , is 5-10 mg Its requirement is increased to about 20 mg , during lactation .

26. Dietary sources Wheat germ oil is the richest source of vitamin , vegetable oils, such as s af flower oil, cottonseed oil and sunflower oil, and nuts and seeds, are good sources of vitamin E.

27. Functions . Vitamin E acts as an antioxidant .• It stabilizes cell membrane and prevents cells from damage by free radicals Cells damaged by free radicals, are prone to mutations, thus,vitamin E helps to prevent cancer .

28. absorbtion .metabolism.s t orage.and excretion Vitamin E is absorbed in the upper small intestine. Absorbed vitamin E is incorporated into chylomicrons transported into lymph and then enters blood • It is delivered to the liver and is incorporated into VLDL . Within the cells, intracellular transport of the tocopherol requires an intracellular tocopherol binding protein (TBP).

29. Adipose tissue stores about 90% of the vitamin E .Vitamin E is oxidized, conjugated with glucuronic acid and secreted in the bile and excreted in the faeces . .. E xcreted in the urine as water soluble metabolites

30. Vit E with lipids Passive diffusion. Small intestine Chylomicrons. Lymph. Blood. Portal circulation. Liver. Vit E+VLDL. Tocopherol binding proteins. Intracellular transport. Adipose tissues . Oxidised and conjugated. Vitamin E glucuronic acid. Excreted in bile and through fecal matter and through urine

31. Deficiency diseases Vitamin E deficiency seen in persons with fat malabsorption syndrome, such as cystic fibrosis .premature hemolysis neurological problems that affect spinal cord and peripheral nerves.

32. Hypervitaminosis High doses of vitamin E have negative effects on other fat soluble vitamins Vitamin E interferes with the absorption of vitamin k .Large doses of vitamin E is hazardous to people taking anticoagulant medication, such as warfarin and aspirin.

33. VITAMIN K Vitamin K refers to a family of compounds known as napthoquinones . These include vitamin K1 (phylloquinone ) obtained from plant sources), vitamin K2 ( menaquinone) , obtained from animal sources and synthesized by intestinal bacteria) vitamin K3 ( menadione) , available commercially

34. Recommended daily allowances Daily intake of vitamin K for ad ults, is 60-100 ug. Dietary sources Intestinal b acteria can synthesize and meet about 10-15% of the daily requirement of vitamin K .. Green leafy vegetables like s pinach, broccoli, vegetable oils like soybean oil, cottonseed oil . Animal products, milk and milk products

35. Functions It is required for blood-clotting for the production of prothrombin, factor VIII, factor IX and factor X, and fibrin . Vitamin K also helps to make o steocalcin , which is required for mineralization and maturation of bone.

36. Absorption, storage, metabolism and excretion Vitamin K is absorbed in small intestine, and colon by passive diffusion. Absorbed vitamin is incorporated into chylomicrons in the lymph, enter plasma taken to the liver , where it is incorporated into LDL delivered to peripheral tissues by LDL. metabolites are excreted in the faeces, via the bile. .Menadione is excreted, in the urine as a phosphate, sulfate or glucuronide derivative

37. Vit K with lipids Passive diffusion. Small intestine and colon Chylomicrons. Lymph. Blood. Portal circulation. Liver. Vit k+LDL. Peripheral tissues Oxidised and conjugated. Vit k gucoronic acid Excreted in bile and through fecal matter and through urine as phos phates ,sulfates, glucuronide derivatives

38. Deficiency diseases Vitamin K deficiency seen in fat malabsorption syndromes, such as celiac disease, , cystic fibrosis prolonged use of antibiotics, which destroys intestinal bacteria. People who are on anticoagulants the newborn babies also have a risk of vitamin K deficiency (since newborn babies lack intestinal bacteria).

39. Deficiency disorders Bleeding disorders
Easy bruising
Oozing from the nose or gums
Excessive bleeding from GI tract
Blood in the urine and stool
Heavy menstrual bleeding