14 WATER SOLUBLE VITAMINS Vitamins Quiz Study Guide 4 o Not a source of energy o Individual units in milligrams or micrograms not grams like macronutrients o Need less than macronutrients o Variety is important No single food group has all vitamins Water Soluble vs Fat Soluble Vitamins o Solubility affects 1 absorption 2 transport 3 storage Water Soluble Vitamins Absorption Dissolved in watery compartments of food Transport Directly into bloodstream Storage Not stored in appreciable amounts Excess filtered out by kidneys Vitamin B12 can be stored in liver Fat Soluble Vitamins Absorbed with fatty acids micelles Absorb 40 90 of intake efficiency decreases as intake needs Lymph then blood where transported by lipoprotein carriers Accumulate and stored indefinitely in the liver or adipocytes o Water soluble o Fat soluble B Vitamins Vitamin C Absorbed straight into the blood stream Vitamins A D E K Form micelles and go to the lymph system and then blood system Vitamin Content of Foods harvesting o Plant foods affected by soil sunlight growing conditions maturity at o Affected by packaging storage processing and cooking Light affects riboflavin why milk is stored in opaque bottles o Water soluble vitamins stir fry steam microwave don t boil o Enrichment Fortification Enrichment adding something back that was taken out Only endosperm remains and bran germ are removed when whole grains are refined enriched with thiamin niacin riboflavin folate iron still missing fiber vitamin E phytochemicals vitamin B6 zinc magnesium Fortification adding something new Vitamin Bioavailability the extent to which a nutrient is absorbed and utilized by the body o Affected by digestion efficiency GI transit time previous intake nutrition status method of food prep source of nutrient other foods eaten concurrently Water Soluble Vitamins o Thiamin o Riboflavin o Niacin o Pantothenic Acid o Vitamin B6 Pyridoxine o Vitamin B12 o Folate o Biotin o Vitamin C Have Upper Limits Niacin Vitamin B3 Vitamin B6 Pyridoxine Folate Vitamin C Choline Have Adequate Intakes Pantothenic Acid Biotin B Vitamins o Act primarily as coenzymes in energy yielding metabolic pathways o Thiamin Main Function Thiamin coenzyme thiamin pyrophosphate TPP decarboxylation reactions removing carbons results in CO2 participates in Pyruvate to Acetyl CoA Citric Acid Cycle Pentose Phosphate Pathway Occupies a special site of nerve cell membranes Highest Source pork Deficiency beriberi muscle weakness nerve degeneration loss of appetite Most often seen with alcoholism Rare due to enrichment of refined grains Main Function oxidation reduction reactions Flavin adenine dinucleotide FAD FADH2 o Citric Acid Cycle and Beta oxidation of fatty Flavin mononucleotide FMN FMNH2 o Works in the Electron Transport Chain to move acids electrons UL o Riboflavin Highest Source milk Deficiency Ariboflavinosis cracking of corners of the mouth inflammation of mouth and tongue Vulnerable to light UL o Niacin Main Function coenzyme oxidation reduction reactions Niacin NAD Electron Acceptor ATP synthesis Highest Source protein rich animal foods Can have preformed niacin and niacin formed from tryptophan Deficiency Pellagra Niacin deficiency Pellagra 4 D s Dementia Diarrhea Dermatitis Death UL Niacin Flush excess niacin causes liver toxicity Can be given in large amounts to reduce blood lipid levels o Vitamins B1 B2 B3 reactions o Pantothenic Acid All incorporated in coenzymes that catalyze energy yielding Deficiencies are rare but alcoholics are at the highest risk Main Function component of coenzyme A forms Acetyl CoA Deficiency rare UL Has an adequate intake o Vitamin B6 Main Function coenzyme pyridoxal phosphate PLP Amino acid metabolism and synthesis transamination reactions Synthesis of other neurotransmitters o Used to synthesize essential amino acids Conversion of tryptophan to niacin and to serotonin Release of glucose from glycogen Lowers levels of homocysteine Blood cell synthesis o Microcytic small hypochromic pale anemia red blood cells lack sufficient hemoglobin to carry oxygen Deficiency depression confusion wave patterns convulsions microcytic hypochromic anemia Prolonged mega doses can cause irreversible nerve damage UL o Vitamin B12 Main Function maintains myelin sheath folate metabolism 5 methyl THF THF required for cell division homocysteine methionine Deficiency Pernicious anemia megaloblastic anemia neurological damage without treatment nerve degeneration becomes irreversible ultimately fatal UL Stored in large amounts in the liver Absorption binds to R protein to protect it from intestinal bacteria Trypsin cleaves B12 from R protein B12 binds to intrinsic factor made in the stomach B12 IF border absorbed transferred to transcobalamin II carrier protein within the cell B12 deficiency causes folate deficiency NUTRIENT OF CONCERN FOR VEGANS VEGETARIANS Biotin o Main Function carboxylation reactions adding CO2 to substrate replenishes oxaloacetate from pyruvate for continuation of Citric Acid cycle o Deficiency rare o UL o Has an adequate intake Folate o Main Function folic acid coenzyme tetrahydrofolate THF accepts and donates one carbon units essential for human embryonic development neural tube defects red blood cell maturation homocysteine methionine amino acid metabolism DNA synthesis cell division o Major Source FRESH fruits veggies o Deficiency most prevalent of all deficiencies megaloblastic anemia abnormally large red blood cells weakness fatigue irritability etc Causes neural tube defects in women of childbearing age o UL from supplements fortified foods May mask a vitamin B12 deficiency o RDA expressed in terms of dietary folate equivalents Vitamin C Ascorbic acid o Main Function indirectly activates enzymes antioxidant function collagen synthesis synthesis of vital cell components o Dietary sources FRESH fruits veggies o Deficiency Scurvy o UL Can lead to GI distress diarrhea Choline o Main Function essential nutrient synthesize lecithin and neurotransmitter acetylcholine support neural tube closure o Deficiency rare o UL Hypotension sweating diarrhea fishy body odor o Body can synthesize most not all of body s needs 15 WATER THE MAJOR MINERALS Water o Most important nutrient o No capacity to store water o Can only survive a few days without it o Body is 50 75 water Hydration constant body s water composition o Water s polarity makes it a great solvent o Functions 1 Maintains fluid balance 2 Delivery of nutrients and removal of waste 3