Vitamins & Minerals Metabolism

Remember this? … specific mechanisms of absorption for the vitamins and minerals will not be covered in this course… just recall the effects of fiber (or lack thereof) and imagine how it may affect absorption of vitamins & minerals…

Some Notes on Vitamin & Mineral Uses Mg ++ must be present for the ATP (or ADP) to bind To synthesize ATP molecule in the first place you need Folic Acid, Thiamine, Cobalamin, PO 4, Zn +, Cr ++, & Mg ++ Niacin is a component of NAD + Vitamin & Mineral uses are illustrated within the metabolic pathways...

Obviously, in order for the metabolic pathways to work, the enzymes (proteins) must be synthesized in the first place... Some Nutritional Requirements For This Process Include: Protein synthesis - requires DNA, RNA, mRNA, GTP... - synthesis enzymes require Cr +?, Mg ++, Zn + to function and amino acids for structure Synthesis of DNA, RNA, ATP, GTP... - folic acid, B 12, glucose, aa, PO 4 (structure)

You’ve seen this before... Only now it is labeled with some nutrient requirements

In the previous slide, transcription was activated by the signaling molecule (estrogen) binding to the actual promoter – resulting in dimerization and DNA binding. Other signaling molecules (growth hormone, calcium / diacyl-glycerol, interleukins, various growth factors, and a host of others) can activate promoters by activating an enzyme cascade which ultimately results in promoter activation.

More Notes on Vitamin & Mineral Uses Thiamin is a component of PDH & αKGDH Riboflavin is a component of FAD + Iron and Sulphur are part of the enzyme Aconitase Pantothenic Acid is a component of CoA Pyridoxine (as pyradoxal phosphate) is a cofactor for transamination reactions

And More Notes on Vitamin & Mineral Uses Iron is a component of complex III and cytochrome c and both Iron and Copper are components of cytochrome c oxidase Ascorbic Acid is necessary for the synthesis of carnitine Even More Notes on Vitamin & Mineral Uses Riboflavin, Iron, and Sulphur are components of complex I Iron and Sulphur are part of the CoQ complex

Dietary Notes On Some Vitamins & Minerals RDAFood Sources Magnesium 19 – 30 yrs 310 & 400 mg/day ♀ & ♂ Dark green vegetables, milk, tea, coffee, cocoa, whole grain 31 to 50 yrs 320 & 420 mg/day ♀ & ♂ cereals Folic Acid400 µg /day ♀ & ♂ High levels in yeast, organ meats, fresh green vegetables, some fresh fruits Thiamine (B1)1.1 & 1.2 mg/day ♀ & ♂ Whole grain cereals, organ meats, lean pork, and yeast Cobalamin (B12)2.4 µg/day ♀ & ♂ Organ meats, meat and meat products, clams, oysters, legumes Niacin14 & 16 mg/day ♀ & ♂ Yeast, lean meats, liver, legumes, and poultry Riboflavin (B2)1.1 & 1.3 µg/day ♀ & ♂ Eggs, lean meats, organ meats, green leafy vegetables, enriched cereals Pantothenic Acid (AI)5 mg/day ♀ & ♂ Ubiquitous: high levels in animal protein, legumes, and whole ‑ grain cereals Pyridoxine (B6)1.3 mg/day ♀ & ♂ Meats, poultry, fish, wheat bran, some in: milk, eggs, green leafy vegetables Ascorbic Acid75 & 90 mg/day ♀ & ♂ Citrus fruits and strawberries, tomatoes, potatoes, broccoli, cauliflower, spinach, cabbage, and brussel sprouts Phosphorus700 mg/day ♀ & ♂ Ubiquitous: milk & dairy, meats, phosphoric acid in carbonated drinks Zinc8 & 11 mg/day ♀ & ♂ lots in shellfish, egg white, some in most animal and plant foods Chromium(AI)25 & 35 µg/day ♀ & ♂ Mushrooms, brewers' yeast, prunes, nuts, asparagus, eggs, shellfish, cereals (bran), wine, beer Iron18 & 8 mg/day ♀ & ♂ Meats, liver, clams, oysters, dried fruits, nuts, cereal products SulphurNone necessaryAll protein foods Copper900 µg/day ♀ & ♂ Shellfish and legumes, bananas, potatoes, bran, liver

Food Group Sources of Vitamins & Minerals DairyFruitsVeggiesMeats &Beans &Nuts &Breads & Eggs LegumesSeeds Cereals MagnesiumXGreenXX Folic AcidXGreenX Thiamine (B1)XX Cobalamin (B12)XX NiacinXX Riboflavin (B2)GreenXX (enriched) Pantothenic AcidXXX Pyridoxine (B6)XGreenXX Ascorbic AcidXGreen PhosphorusXX ZincXX ChromiumX (prunes)XXX (bran) IronX (dried)X XX CopperXStarchyXXX (bran)

Food Servings for Different Caloric Intakes - (Adapted from Optimal Health Guide) kCal* Dairy Fruits Veggies Green Yellow Starchy Other Meats / Fish / Eggs Beans & Legumes / Nuts & Seeds Breads / Cereals Added Fats *1900 kCal intake meets RDA requirements on average; 2200 or more exceeds requirements...

Oxygen Radicals and Antioxidants Remember that various electron carriers such as NADH, FADH 2, & Co-Q can auto-oxidize to produce superoxide anions or hydrogen peroxide... In the presence of ferric iron (3+), this reaction is greatly speeded up...

Reactive Oxygen Species (ROS) can damage many different molecules in cells - leading to a variety of serious problems... the production of various carcinogens from peroxidized lipids is just one possible outcome...

Vitamin E reacts with a peroxyl radical to become a stable radical

Vitamin C also reacts with ROS to become a stable radical

Dehydroascorbate & ascorbate radical can be reduced back to ascorbate...

Once a stable vitamin E radical has been formed. It can be reduced by vitamin C, which, in turn, can be reduced by glutathione Continual recycling between vitamin E, vitamin C, and glutathione ensures a stable antioxidant environment... dependant on continued synthesis of glutathione and consumption of vitamin c

β-Carotene is a very effective singlet-oxygen scavenger

β-Carotene also can function as a chain-breaking antioxidant... though not nearly as well

Dietary Notes On Some Antioxidant Vitamins RDAFood Sources Ascorbic Acid75 & 90 mg/day ♀ & ♂ Citrus fruits and strawberries, tomatoes, potatoes, broccoli, cauliflower, spinach, cabbage, and brussel sprouts α-tocopherol15 mg/day ♀ & ♂ Vegetable oils and wheat germ Carotenoids N/ATomatoes, green & yellow vegetables (ß-carotene, lutein, lycopene...)

Food Group Sources of Antioxidants DairyFruitsVeggiesMeats &Beans &Nuts &Breads & Oils Eggs LegumesSeeds Cereals Ascorbic AcidXGreen α-tocopherolXX (vegetable) SeleniumXX Carotenoidsgreen yellow

Other antioxidant compounds (phytochemicals) exist and are easily obtained in the diet... (later!)

Enzymatic Antioxidant Systems Zinc / Copper: cytosolic / extra cellular Mn: mitochondrial SOD Fe

Dietary Notes On Requirements for Some Antioxidant Enzymes RDAFood Sources Iron18 & 8 mg/day ♀ & ♂ Dried fruits, nuts, cereal products, organ & other meats - component of catalaseseeds, green leafy vegetables Zinc11 & 8 mg/day ♀ & ♂ Wheat germ, whole grains, beef, poultry, oysters - component of cytosolic & extracellular superoxide dismutase Copper 900 ug ♀ & ♂Whole grains, liver, legumes, eggs, meats, shellfish - component of cytosolic & extracellular superoxide dismutase Manganese1.8 & 2.3 mg/day ♀ & ♂ Wheat bran, nuts, poultry, legumes, meat - component of mitochondrial superoxide dismutase Selenium35 µg/day ♀ & ♂ Seafood, organ and red-meats, whole grains, dairy - component of glutathione peroxidase

Food Group Sources of Antioxidants DairyFruitsVeggiesMeats &Beans &Nuts &Breads & Oils Eggs LegumesSeeds Cereals IronXXXXX Green leafy ZincXX beef/poultry oysters CopperXXX eggs/meats shellfish ManganeseXXX beef/poultry SeleniumXXX organ/red meats fish

Repeated exercise will enhance these enzyme systems in muscle, liver, lung, brain, etc... raising the issue that in spite of some claims by the “health-food” industry... there may be no real enhanced nutritional requirement for the vitamin antioxidants with exercise...

Unfortunately, the average american diet Really Sucks... Adapted from Nutrition for Sport and Exercise, Dunford & Doyle, 2008

Resulting in an almost non-existent probability of being adequate... Adapted from Nutrition for Sport and Exercise, Dunford & Doyle, 2008