Unformatted text preview: 9/9/09 Chapter 1 Part 3 Vitamins Minerals Organic compounds Inorganic compounds < 100 mg Important supporting role Vitamins differ from food stuffs More notable by their absence Trace elements Both deficiencies and excesses of the vitamins can affect health. Structure separate units Function do not provide calories Amounts measured in micrograms or milligrams 1 9/9/09 Dietary intake Bioavailability is the rate and extent that a nutrient is absorbed and used. 50-90% of B vitamins are absorbed Digestion Transit time Nutrition status Combination of foods consumed Preparation method Source synthetic, fortified, naturally occuring Precursors (provitamins) Active vitamins in the body. Vitamins in foods may be in inactive form Organic easily destroyed by exposure to: Fluorescent light, ultraviolet rays of sun Oxidation Prolonged cooking Improper storage Milling losses Eat foods soon after harvest Nutrients lost through milling of grains Grain/cereal products enriched Whole grains contain original nutrients Thiamin, riboflavin, niacin, folate, iron Still deficient in B-6, magnesium, zinc B vitamins Each vitamin unique Deficiencies Toxicities Food sources Coenzymes that assist enzymes in the release of energy. Participate in metabolism and cell multiplication. 2 9/9/09 8 B-complex vitamins + Vitamin C = 9 water soluble vitamins Named in order of discovery Body cannot make (indispensible) Marginal deficiency more common Vitamin B1 thiamin Vitamin B2 riboflavin Vitamin B3 niacin Vitamin B6 pyridoxine Vitamin B12 Biotin Pantothenic acid Folic acid Vitamin C 3 9/9/09 Insoluble in water, soluble in organic solvents Require bile for absorption, absorbed with fat Transported in chylomicrons Stored in liver, adipose tissue Require protein carriers Not readily excreted; toxicity Problem if fat malabsorption present Vitamin Vitamin Vitamin Vitamin A D E K Inorganic Elements Major minerals Retain their chemical identity when exposed to heat, air, acid, or mixing. Minerals only lost when they leach into water. 4 9/9/09 Various functions in the body Major Minerals Trace Require >100 mg /day Calcium, phosphorus Require < 100 mg/day Iron, zinc The Body's Handling of Minerals Minerals Variable Bioavailability Some behave like water-soluble vitamins. Some behave like fat-soluble vitamins. Excessive intake of minerals can be toxic. Binders in food can combine chemically with minerals and prevent their absorption. Phytates are found in legumes and grains. Oxalates are found in spinach and rhubarb Animal products are better absorbed Plants depend on mineral content of soil Refinement lowers mineral content Not all are replaced Nutrient Interactions Varied Roles Sodium and calcium Phosphorus and magnesium Often caused by supplements Sodium, potassium and chloride function primarily in fluid balance. Calcium, phosphorus and magnesium function primarily in bone growth and health. 5 9/9/09 Mineral-mineral competition Vitamins-mineral competition Similar size Similar electrical charges Ex: magnesium, calcium, iron, copper Competition for absorption Vitamin C improves iron absorption Vitamin D improves calcium absorption Alcohol (drinking) = ethyl alcohol, ethanol Metabolism Interferes with nutrition Behaves like a drug, alters body functions Potential health benefits to moderate consumption(?) Alcohol in drinks 5 ounces of wine 10 ounces of wine cooler 12 ounces of beer 1 ounces distilled liquor (80 proof) Proof is approximately twice the alcohol% by volume) 6 9/9/09 Requires no digestion Simple diffusion Broken down by alcohol dehydrogenase Quickly absorbed through stomach - Women have less ADH in stomach More alcohol absorbed through intestine Depends on rate of stomach emptying 20-25% of the ethanol can reach brain in a few minutes Rate of absorption Alcohol is found wherever water is found in the body Easily moves through the cell membrane Potentially toxic Wine liqueur beer (slowest) Normal conditions Alcohol Liver used FA for fuel Combine with triglycerides tissues Liver has most alcohol dehydrogenase FA accumulate, fatty liver Change liver cell structure Replaced with scar tissue 7 9/9/09 Converts alcohol to acetaldehyde Coenzyme NAD (niacin) H+ carrier Other processes needing NAD-stop NADH accumulates Acetaldehyde acetate Acetyl CoA Liver deals with alcohol Fatty liver Fibrosis Cirrhosis Inadequate NAD - blocked from entering TCA Alternate route FA Triglycerides Accumulation of fatty acids Permanently alter liver structure 8 9/9/09 Asians and Native Americans Major cause of death for Native Americans African American Alcoholics Alcohol-related motor vehicle accidents Suicide, homicide, domestic abuse Very susceptible compared to Caucasians Hispanic American Alcoholics Greater risk for tuberculosis, hepatitis C, HIV/ AIDS Greater risk for cirrhosis-related deaths 9 9/9/09 Addictive and dangerous Long-term drinking poses risk for all Drinking increasing quantities Genetic influence Tolerance to alcohol Be aware of alcohol consumption Children of alcoholics are 4x more likely to become alcoholics themselves Warn children of alcoholic families of the dangers by age 10 Heavy drinkers may have inadequate food intake. Impaired nutrient metabolism will result from chronic alcohol abuse. Vitamin B6, folate, thiamin deficiencies Protein Metabolism Interferes with amino acid absorption (GI) Increase in urea nitrogen Impairs liver amino acid uptake Decreases gluconeogenesis 10 9/9/09 Fatty infiltration of the liver Increased synthesis of fat Enlarged fat cells Scar tissues Choke off nutrient and O2 supply to liver cells Engorged fat cells burst and die Can occur in ten years 3 beers/day for men 1/1/2 beers/day for women 50% chance of death within 4 years Advanced stages are not reversible Destruction of vital tissues regardless of diet 11 9/9/09 Required in diet for growth, health, survival Not synthesized by body Inadequate intake results in deficiency disease Failure to grow Essential Nonessential Conditionally essential Myopathy Decreased protein synthesis Glutamine Carnitine Dietary reference intake (DRI) Estimated average requirement (EAR) Recommended dietary allowance (RDA) Adequate intake (AI) Tolerable upper intake level (UL) Levels for all vitamins and minerals 12 9/9/09 Provide practical approach to food choices Six categories Number of servings 13 9/9/09 55% fructose Cornstarch mixed with acid and enzymes Starch is broken down to glucose Some glucose is converted to fructose Cheaper than sucrose Does not form crystals Brown sugar Turbinado sugar (raw sugar) Maple syrup Honey Sugar alcohols (sorbitol, xylitol) Cyclamates ~2.6 kcal/g Absorbed and metabolized slower "Excess consumption may have a laxative effect" Banned in 1970 Sweetener in Tab, diet Coke product Thought to cause bladder cancer in rats Approved in over 55 countries Not very sweet 14 9/9/09 First produced in 1879 180-200x sweeter than sucrose No potential risk in humans Had been used with cyclamates no longer considered risk for bladder cancer Composed of phenylalanine, aspartic acid, and methanol 180-200x sweeter than sucrose 4 kcal/gm Not heat stable Complaints of sensitivity Acceptable daily intake: 50 mg per kg body weight (FDA) (~14 cans of diet soda for average adult per day) Headaches, dizziness, seizures, nausea, etc. Warning label for Phenylketonuria (PKU) Phenylalanine-amino acid for PAH-phenylalanine hydroxylase Gene mutation inactivates PAH Protein synthesis Hydrolyze to tyrosine Buildup of phenylalanine Mental retardation Organ damage Not seen until 3 to 6 months of age Needs to be treated before 3 weeks Newborn screening Treatment Minimize phenylalanine Supplement tyrosine 15 9/9/09 Approved by FDA 200x sweeter than sucrose Not digested by the body Heat stable Diabetisweet used in baking Developed by Nutrasweet FDA approved for general-purpose sweetener Similar structure to Aspartame Is not broken down in the body 7,000-13,000x sweeter than sucrose Heat stable Safe for use 600x sweeter than sucrose Substitutes chlorines for hydroxyl groups on sucrose Heat stable Tiny amount digested Excreted in the feces "made from sugar so it tastes like sugar" Largest market share 2 to 3 times Equal and Sweet `N Low No long term human toxicity studies Sucralose starts out as sugar, then changed into a fructo-galactose molecule This molecule doesn't exist in nature Body doesn't metabolize, may be stored (15%) Making it have zero calories 16 9/9/09 17 ...
View Full Document
This note was uploaded on 09/20/2009 for the course HEED 3301 taught by Professor Staff during the Spring '08 term at UT Arlington.
- Spring '08