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CALCIUM

CALCIUM. Becca Curry Katie Glynn Laura Hardy Megan Solloway. http:// enabledkids.ca/?p =2286. Overview. Introduction Dietary Sources Absorption Excretion Major Functions Clinical Functions Questions. Introduction. http://www.youtube.com/watch?v=82yZVB7IDlE

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CALCIUM

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  1. CALCIUM Becca Curry Katie Glynn Laura Hardy Megan Solloway http://enabledkids.ca/?p=2286

  2. Overview Introduction Dietary Sources Absorption Excretion Major Functions Clinical Functions Questions

  3. Introduction http://www.youtube.com/watch?v=82yZVB7IDlE In honor of the up coming breakhttp://www.youtube.com/watch?v=LwnzWyktX_U http://www.youtube.com/watch?v=up4XM48cStA

  4. Dietary Sources http://energy.healthfoodxdrinks.com/calcium-rich-foods-that-keep-your-bones-strong/ • Supplements, Dairy Products, Fruit, Vegetables, and Beans • Roughly half comes from diary sources • Beans and vegetable sources have a higher absorption rate ~60% in comparison to dairy sources ~ 30% • Fortified foods have roughly same absorption rate as dairy products • Calcium Citrate Malate

  5. Supplements • Calcium Carbonate and Calcium Citrate • Carbonate should be taken with food • Citrate does not need to be taken with food • Amount of elemental calcium • Symbols for Lab testing • At home: place supplement in a glass of lemon juice, stir at intervals for 30 minutes. • If not dissolved after 30 minutes suggested to find a different supplement

  6. Studies • Study conducted by Angel R. et al. to analyze how differing calcium sources impacted ‘postmenopausal’ mice • Dairy forms showed lower adipose fat for mice • Supplement (calcium carbonate) form revealed higher bone density

  7. Absorption

  8. When is Calcium Absorption High? • During times that the body needs more such as growth periods and pregnancy • In a low pH environment • Lactose • Fat Intake • Vitamin D levels • Exercise http://www.bcps.org/offices/lis/models/life/humanchart.htm

  9. When is Calcium Absorption Low? • Deficient in Vitamin D • Insoluble fiber • Oxalate and Phosphorus • Alcohol consumption • Caffeine • Sodium

  10. Calcium Absorption • The amount we absorb depends on how much calcium we normally intake • Digested mainly in small intestines and very little in large intestine • Three general mechanisms of calcium absorption • Transcellular active transport process • Paracellular (passive) • Some Calcium Absorption in Large Intestine http://www.finerminds.com/health-fitness/foods-that-fight/attachment/calcium-food/

  11. Transcellular Active Transport Absorption • Only in duodenum when the calcium intake is low • Requires ATP • The calcium crosses the intestinal brush border • Calcium crosses plasma membrane via calcium channels • Ca ATPase mediates the extrusion of calcium and is located in the basolateral membrane.

  12. Paracellular Absorption • Occurs only in jejunum and ileum when calcium intakes are moderate or high • No ATP required • Concentration gradient is set up between the calcium in the lumen and in the basolateral side of the eneterocyte • Ionized calcium diffuses through tight junctions between intestinal cells.into the basolateralspaces around the enterocyte and enters into the blood. • Responsible for most of calcium absorption because the calcium has a short amount of time for active transport in the duodenum

  13. Calcium Absorption in Large Intestine • Bacteria releases calcium that is bound to fermentable fibers (ex: pectins) • 4%- 10% of dietary calcium is absorbed by the colon each day http://www.argosymedical.com/Digestive/

  14. Excretion

  15. Basics • Excess calcium that cannot be stored is excreted in urine, feces and sweat • Urinary loss: incomplete reabsorption • Fecal loss: endogenous sources (bile) not reabsorbed by intestines • Diet can directly effect excretion

  16. Regulation: Hormones www.mayoclinic.com • Hormones regulate blood levels • Parathyroid Hormone • Calcitriol • Calcitonin • Estrogen

  17. Regulation: Diet • Phosphorus • Increases reabsorption & uptake by bone • Sulfur • Sulfur-containing amino acids in protein • Sulfur  Sulfate • Sulfate binds to Calcium • Prevents both bone incorporation and kidney reabsorption • Sodium • “Every extra 2 grams of dietary sodium increases calcium excretion by 30-40 mg”

  18. http://ajcn.nutrition.org/content/88/4/1159.full.pdf

  19. Increase Calcium Excretion • High-Sulfate Animal Protein • Sodium • Coffee • Tea • Alcohol

  20. Decrease Excretion • Alkalogenic diets • Fruits • Vegetables

  21. Major Functions

  22. Calcium and Bones: a Quick Breakdown • Bones & teeth = 99% of body’s Ca stores • Most prevalent mineral in bone • Bones = LIVINGtissue • Protein strengthened by calcium and phosphorus deposits • Calcium + phosphorus = hardness • Collagen = flexibility and strength

  23. Osteoblasts= “bone formers” = produce bone collagen fibers • Collagen fibers are laid down • Osteoblasts extract calcium, phosphorus, and other nutrients from the bloodstream Ossification • Osteoblast supervise deposits of sharp, calcium phosphate crystals over top of the collagen layers • Crystals act as “cement” and give bone its white appearance

  24. Calcium: Everywhere Else! • Only 1% of calcium found outside the bone = critical! • Important for: • Blood clotting • Blood pressure stabilization • Normal brain function • Cell communication • Muscle contraction • Reproductive health • ……and much more!

  25. Low Blood Calcium Levels Calcium Regulation

  26. High Blood Calcium Levels

  27. Ionized Calcium • Calcium circulating in the blood that carries an electrical charge • Accounts for about ½ of circulating calcium • Particularly important in: • Cell function • The coagulation cascade • Muscle contraction

  28. Ionized Calcium: Cell Function • Calcium used to transport nutrients and waste across the cell membrane • Muscle/nerve/heart cells use a calcium gradient for contraction and neural transmission • Ex. Sodium Calcium Exchanger (antiport) • Uses sodium to remove large amounts of Ca in the cell quickly, particularly after an action potential

  29. Ionized Calcium: The Coagulation Cascade Involved at several steps of the cascade Activates platelets that produces the blood clot

  30. Ionized Calcium: Muscle Contraction Neural impulse signals SR to release large amounts of Ca into the myofilaments Increase in Ca concentration causes shortening of myofilaments = muscle contraction Neural signal stops = SR calcium channel closes = muscle relaxes

  31. Ionized Calcium: Muscle Contraction • Slow Twitch vs. Fast Twitch • Fast Twitch = more developed SR • Faster Ca release upon neural signal • Faster contraction upon neural signal = explosive movements

  32. Clinical Conditions

  33. Calcium & Bone Health • Osteopenia & Osteoporosis • Peak bone mass density (BMD) around age 30 • Calcium intake essential prior to/in this period • Most common in elderly, postmenopausal women • European, Asian, family history • Smoking, alcohol, no weight-bearing exercise

  34. Calcium and Bone Health • Osteopenia & Osteoporosis • Low bone density • Thin, brittle, porous

  35. Calcific Tendinitis • Deposits may form as reaction to trauma • Pain, stiffness • Most often in shoulder- rotator cuff • 30-50 years old, women • Diagnose w X-ray • Treatment • Rest, ice, medicine • Surgical break-up or removal

  36. Calcium & Kidney Disease Dysregulation of calcium metabolism in they body leads to elevated risk of vascular calcification Excessive calcium intake may lead to kidney stones

  37. QUESTIONS? 

  38. References All about Calcium Supplements. Department of Health. Available at http://www.health.ny.gov/diseases/conditions/osteoporosis/calcium_supplements.htm Angel R., Berrigan D., Nunez N., Hursting S., Perkins S., Dietary Calcium Source Influences Body Composition, Glucose Metabolism and Hormone Levels in a Mouse Model of Postmenopausal Obesity. In Vivo. Available at http://iv.iiarjournals.org/content/23/4/527.full.pdf+html BronnerB. Calcium Absorption – A Paradign for Mineral Absorption. American Society for Nutritional Services. 1998; 5: 917-920. Calcium. Office of Dietary Supplements: National Institute of Health. Available at http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/ Fleming K., Heimbach J. Consumption of Calcium in the U.S.: Food Sources and Intake Levels. TAS 2007. Available at http://jn.nutrition.org/content/124/8_Suppl/1426S.long Gropper SS, Smith JL. Advanced Nutrition and Human Metabolism, 6th ed. Belmont, CA: Wadsworth; 2012. Lanou AJ., Should Dairy be Recommended as Part of a Healthy Vegetarian Diet? Counterpoint. Am J ClinNutr May 2009 vol. 89 no. 5 1638S-1642S. Peacock M. Calcium Matabolism in Health and Disease. CJASN. 2010; 5: 23-30.

  39. References Guéguen L, Pointillart A. The bioavailability of dietary calcium. J Am Coll of Nutr. 2013; 19: 119S-136S. Fenton TR, Eliasziw M, Lyon AW, et al. Meta-analysis of the quantity of calcium excretion associated with the net acid excretion of the modern diet under the acid-ash diet hypothesis. Am J ClinNutr. 2008;88:1159 – 1166. Calcium Deposits and Tendinitis (Calcific Tendinitis). WebMD. 2011.

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