Lecture 16 Flashcards

Question

Vitamin A and Protein synthesis/Cell differentiation

Answer 1

Vitamin A very important in cell differentiation Mucous membranes have high turn over cells - and RBC and immune cells. all require vit A -Vitamin A maintains healthy cells in the mucous membranes -W/o vitamin A, the normal structure and function of the cells in the mucous membranes are impaired -poor mucous membrane production -poor turn over of cells in mucous membrane- lungs and gut -more susceptible to infection -endemic vit A deficiencies, when children given vaccines also given large intramuscular dose of Vit A - to ensure body can utilise immunisation effectively, to convert vaccine in body. If body Vitamin A replete, then immunisation worthless

Answer 2

tiny bumps on uneven skin surface | -poor immune response/high susceptibility to infection - distinguishable feature of Vit A deficiency

Answer 3

Vit A fat soluble vitamin, therefore could cause toxicity 1. Vit A (fat soluble) toxicity can cause severe liver damage - Overconsumption from supplements/ Anti-acni medication which is predominantly retinal 2. Beta carotene (water soluble therefore harder to reach toxity) - found in many fruits and veges - Inefficient conversion - Overconsumption from food - yellow skin (common in young children/toddles. Like sweet vege , and comes in numerous forms) - face and palsm fo hands. Not dangerous, and is reversible/not longterm)

Answer 4

could argue vit D isnt nutrient, as main way of manufacturing vit D is from sunlight, and behaves alot like a hormone in body -Calciferol -1,25 dihyrdoxy cit D (calcitrol)- metbaolically active form. can be prescribed Animal version : vit D3 or cholecalciferol Plant version: Vit D2 or Ergocelciferol -few animal or plant sources as good Vit D, more sunlight Precursor is the bodys own cholestrol

Answer 5

1. In the skin -needs to be certain UV wavelength and height to manufacture Vit D in skin (NZ north-9 months + south-6 months) -7-dehydrocholestrol ( a precursor made in the liver from cholestrol) ---Ultraviolet light from the sun --> Previtamin D3 (some D3 and D2 from diet but v small as no fortification mandatory of food supply)-- + Foods --> Vitamin D3 (an inactive form) 2. In the liver --Hydroxylation --> 25-hydroxy vitamin D3 3. In the Kidneys --Hydroxylation --> 1, 25 hydroxy vitamin D3 (active form-to be metabolically active in body) Effective supplements need to be Hydroxylated forms of Vitamin D (1,25 hydroxy vitamin D3)

Answer 6

Need to be Hydroxylated forms of Vitamin D (1,25 hydroxy vitamin D3)

Answer 7

``` require around 400 IU (international units) daily Cod liver oil - 1tbps = 1360 IU Salmon, cooked - 100g = 360 IU Milk (fortified. Anlene) - 250ml =260 IU Sardines in oil -100g = 345 IU Beef Liver, cooked - 100g = 30 IU Mushrooms, raw - 1/2 cup =27 IU Egg - 1 whole = 20 IU ```

Answer 8

1. Sun 2. Pre-vitamin D + skin 3. Vitamin D (+ supplements and Salmon) 4. Liver 5. 25(OH)D --> Prostate gland, breast, colon, lung immune cells --> 1,25 (OH)2D --> a) regulation of cell growth (cancer prevention) --> b) Regulation of immune function (diabetes type 1,MS. RA autoimmune disease prevention) -Vitamin D receptors are found on most cells of most organs in the body. Has an effect on many other regulation organs. Research: large dose Vit. D supplementation?- impact on endocrine function (diabetes risk of at risk individuals), autoimmune disease prevention (muscular sclerosis) 6. Kidney --> 1,25(OH)2D --> Calcium, Muscle, Bone health & regulation of blood pressure Insulin production (heart disease and diabetes prevention) -cannot absorb calcium without vitamin D. also important for reabsorption of calcium into bones -Vitamin D hormone behaving,

Answer 9

Adjusted for age, sex, latitude, obesity and overweight - change 31 - similar picture for adults - seasonal levels. (recommended is 50 nmol/L in serum) - spring/summer: median levels above 50 - dont know what this seasonal changes in vit D impact has on health status - countries with mandatory fortification of Vit D in food products (eg. milk products, butters margarines)- big seasonal differences not seen (summer and winter vit D levels)

Answer 10

Vit d important in bone mineral deficiency --> results in poor bone formation 1. Rickets - children Bowed legs - poorly formed long bones of the legs bend outwards as weight bearing activities such as walking began (cannot hold weight in legs) -seen in recent migrants with darker skin. Darker skin takes longer to manufacture same amount of Vit D, due to darker pigemntation. cultures where cover body due to religion. 2. Osteomalacia - adults

Answer 11

Nz good supplement users. People who have: 1. Poor nutrient intake (elderly, dieters (esp those house bound and dont get sunlight), adolescents, vegeterians (dont get all nutrients from balanced diet)) 2. Increased nutrient requirements (children, pregnancy(folate)/lactation) 3. Increased metabolic demands (surgery/trauma/fracture)-feed people artificially/naso-gastrically or intravenously (particularily B vitamins increaed demand for energy) 4. Maldigestion or Malabsorption (liver disease, GI, diarrhea) 5. Drug-nutrient interactions (prednisone/Vit D, diuretics/K,Mg)- nutrient delivery may need to change 6. Medical treatment interactions (chemo/radiation) - over the counter preparations, herbal and dietary supplement use. Methotrexate in cancer treatment 7. Need from pharmacological disease (niacin for hyperlipidemia)- does prescribed much higher RDI nescessary

Answer 12

High regular use of dietary supplements.