The Water Soluble Vitamins B Vitamins and Vitamin C Chapter 10 Part 2 Vitamin C Similar to B vitamins Differs from B vitamins Water soluble Serves as a cofactor for an enzyme Acts as an antioxidant Loses electrons easily Free Radicals Free radical Oxidative Stress production of oxidants and free radicals exceed the body s ability to handle them and prevent Has one or more unpaired electrons Makes it unstable and highly reactive Can damage other molecules damage Vitamin C Roles Antioxidant Acts as this because of its ability to lose electrons easily it can Enhances iron absorption because of its role as an antioxidant Defends against free radicals Protects tissues from oxidative stress Disease prevention Loses electrons easily Requires iron Requires Vitamin C to protect iron from oxidation Matrix for bone and tooth formation Cofactor in collagen formation requires iron and the Vitamin C is protecting from oxidation Acting as cofactor as antioxidant Cofactor in other reactions Transport of fatty acids Conversion of amino acids to neurotransmitters Making of hormones In stress under stress releases Vitamin C Adrenal glands release vitamin C hormones into blood Types of stress that increase vitamin C Infections burns Extremely high or low temperatures Intakes of toxic heavy metals Lead mercury cadmium Chronic use of certain medications Aspirin oral contraceptives Cigarette smoking BIGGEST because of all the free radicals that are formed Prevention and treatment of common cold Con icting and controversial research Deactivates histamine like an antihistamine Some studies show modest bene ts fewer colds fewer days shorter duration About 8 reduction in duration with 200 mg Vitamin C recommendations Prevent overt symptoms of scurvy Absorption maximum Higher vitamin C levels for smokers 200 mg Notable signs of de ciency symptoms of scurvy Gums bleed easily around teeth Capillaries under skin break spontaneously Vitamin C De ciency Scurvy more than a month of inadequate intake Inadequate collagen synthesis hemorrhaging not healing b c not enough collagen Muscles degenerate anemia infection Skin becomes rough brown scaly dry Wounds do not heal no scar tissue Bone rebuilding ceases ends become soft fractures Teeth become loose Psychological signs hysteria depression Death Vitamin C Toxicity Supplementation side effects Diarrhea GI distress UL 2000mg daily Interference with medical regimens Medical conditions in which high doses of vitamin C should not be consumed Vitamin C Food Sources Fruits and vegetables Vulnerable to heat and oxygen prepare foods in a variety of ways Reducing cooking times or not cooking would be Citrus peppers broccoli and other dark green veggies etc Potatoes not highest source but very common highest source in American diet eat a lot of them Also anywhere where potatoes are a staple better to keep Raw fruits provide more Used as antioxidant by food manufacturers Ascorbic acid is a fancy name for Vitamin C Review of Vitamin C Describe free radicals molecules that are short electrons so trying to grab electrons from any source they can get They cause oxidation in body damage in a body Domino effect grab onto something and turn something into a free radical then that free radical goes to grab something else etc This is what this oxidation does Cancer because of this Vitamin C acts as an antioxidant and a cofactor in other reactions List food sources high in vit C citrus peppers and dark leafy vegetables Modest but common source of vit C potatoes Highlight 10 Vitamin and Mineral Supplements Consumer motives Costly all these are not free Question is whether or not you are getting any effect out of the supplement Self prescribed is dangerous If taking let your physician know Improving food choices is the preferred course of action if trying to get a better intake of vitamins and minerals Dietary insurance Health insurance Financially and physically costly Arguments for Supplements Good when correcting overt de ciencies Support increased nutrient needs Certain stages of life Childbearing years iron folate Therapeutic doses when a speci c de ciency Acting as a drug in pregnant woman folic acid iron etc sure that they use the recommended supplements Pregnancy Infancy Vitamin K given in injection in foot for infancy Depending on method of feeding If formula don t need supplements Breastfeeding need to make low kcal intake if can not meet nutrient needs supplement would be recommended Elderly because low kcal intake but also lower absorption Those who eliminate food groups vegetarians don t eat dairy etc Supplements can improve nutrition status Improve body defenses Don t have clear de nitive if vitamin and mineral supplements can reduce disease risk Probiotics when taking antibiotics to reestablish gut ora Who needs Supplements Speci c nutrient de ciencies Low energy intakes Vegans and older adults Lactose intolerance Certain medications Certain stage os life ccle Inadequate milk intake sun exposure or dark skin Medical conditions Men and postmenopausal women should not take excess iron high iron is harmful and de ciency is not likely Who should NOT take supplements heart disease and heart attacks as a result Why are examples like this important Don t self prescribe drug company wouldn t be a good resource best interest is your money not your health resources physicians dietitians clinical controlled trials Comprehensive literature review not person just hired at GMC or Vitamin Shoppe don t have nutrition background Exercise increases iron needs Smokers should not take beta carotene high lung cancer risk and mortality Acts as pro oxidant Postmenopausal women should not take Vitamin A reduces bone density Surgery patients should not take Vitamin E the week before a surgery b c blood thing Arguments Against Supplements Toxicity Supplements users are more likely to have excessive intakes Issues with children Gummies screw cap because of danger that comes with excess thinks it is candy Iron supplements leading cause of accidental ingestion fatalities in children As consumers in charge of knowing how to keep ourselves safe Perception that supplements will be therapeutic No guarantee of supplement effectiveness Do not protect against progression of chronic disease some may increase risk Little enforcement of requirement for statements to be truthful and not misleading Life threatening misinformation Unknown needs Replace healthy foods Replace exercise in muscle building or weight
View Full Document
Unlocking...