Chapter 13 Water Soluble Vitamins Flashcards
Water soluble vitamins
Are essential organic substances that need for normal function, growth and maintenance of body tissues.
Storage of water soluble vitamins
Little amount of WSV are stored in body, so it is less risky to have toxicity.
WSV are easily be destroyed
They can be easily destroyed by cooking, heat, light, air, alkaline substances.
Best way to cook
Steam, stri-fry, and microwave
Cofactors
All B vitamins form coenzymes which is also called cofactors. Metal is another kind of cofactors. Cofactors combine with inactive enzyme to form active enzyme which is able to catalyze specific reactions.
All 8 BV participate in _____
energy metabolism
How much of the BV is absorbed?
About 50 to 90% of the B-vitamins in the diet are absorbed.
Important source of BV
Grains are enrich of BV, minerals, and fiber. But the process of refining remove the germ, husk layers, and bran, and only leave the starch to form white flour.
How much whole grain should be consumed per day?
At least half of the grains consumed daily be whole grain,
BeriBeri
脚气病. Caused by the deficiency of thiamine.(V B1) It has two types, dry and wet.
Food rich of thiamin
Pork products, sunflower seeds, and legumes. Whole and enriched grains and cereals, green peas, asparagus, organ meats (e.g., liver), peanuts, and mushrooms also are good sources.
RDA and DV for thiamin
RDA 1.2 mg/day for adult men and 1.1 mg/day for women
DV 1.5 mg
Upper level of thiamin
No upper level, because it is readily excreted in the urine..
Absorption of thiamin
It is absorbed mostly in small intestine.
Storage of thiamin
Little thiamin is stored in the muscles, brain, liver, and kidneys.
Function of thiamin
It is required for the metabolism of carbohydrates and branched-chain amino acids. It is needed in two reactions, decarboxylation and transketolase. It is also required for normal nervous system.
Thiamin deficiency
Individuals who abuse alcohol, and those with heart failure, gastrointestinal diseases, or eating disorders, as well as the elderly, also are at risk of thiamin deficiency.
How long can be Thiamin deficiency developed?
Some signs of thiamin deficiency can develop after only 14 days on a thiamin-free diet.
How does alcohol influence BV
Alcohol decreases thiamin absorption, alcohol increases thiamin excretion in the urine, and alcoholics may consume a poor quality diet without enough thiamin.
Structure of riboflavin
Ribofl avin contains 3 linked 6-membered rings, with a sugar alcohol attached to the middle ring.
Food source of riboflavin
Almost one-quarter of the riboflavin in our diets comes from milk products. The rest typically is supplied by enriched white bread, rolls, and crackers, eggs and meat. Foods rich in riboflavin are liver, mushrooms, spinach and other green leafy vegetables, broccoli, asparagus, milk, and cottage cheese.
______ causes riboflavin to break down rapidly.
Exposure to light (ultraviolet radiation)
Riboflavin Needs and Upper Level
RDA: Adult men and women are 1.3 and 1.1 mg/day. DV: 1.7mg. No upper level.
Riboflavin is a component of
2 coenzymes that play key roles in energy metabolism: flavian mononucleotide (FMN) and fl avin adenine dinucleotide (FAD).
Functions of riboflavin
Energy metabolism, activation of other B-vitamins, anti-oxidant function
Ariboflavinosis
Riboflavin deficiency. Primarily affects the mouth, skin, and red blood cells.
When will Ariboflavinosis happen
Ariboflavinosis develops after 2 months on a riboflavin-deficient diet and is rare in otherwise healthy people.
What can cause riboflavin deficiency
Diseases such as cancer, certain forms of cardiovascular disease, and diabetes can lead to or worsen a riboflavin deficiency.
Pellagra
A deficiency disease of BV niacin. The only dietary deficiency disease ever to reach epidemic proportions in the U.S.
Two forms of niacin(B3)
Nicotinic acid (niacin) and nicotinamide (niacin amide). Both are used to form coenzyme.
Coenzyme form of thiamin is
Thiamin pyrophosphate (TPP)
Symptoms of riboflavin deficiency
Inflammation in throat, mouth, and tongue.
Food source for niacin
It can also be synthesized from tryptophan. Poultry, meat, and fish. Bread.
Niacin is very ____ stable
heat. It has little loss during the cooking.
Tryptophan, protein, and niacin
60mg try = 1 mg niacin. 1g protein = 10 mg tryp.
RDA and DV for niacin
RDA: 16mg for men, 14mg for women. DV: 20 mg
Upper level of niacin
35 mg. Only for supplement and fortification.
Absorption of niacin
Occurs in stomach and absorbed in small intestine. From active transport to passive diffusion. All of the niacin is absorbed.
Niacin active bioactivity is low in corn because
it bound with protein. But if it can be released
Transport
After absorption, niacin is transported in portal system to the liver to the bed cells. And they are converted to coenzyme in tissues.
Functions of niacin
Coenzyme, oxidation-reduction reactions. required in at least 200 reactions especially ATP production, NAD+ is required for catabolism of carb, fat and protein.
Niacin deficiency
Pellagra
Pellagra
cause the damage on the skin is round the neck.
3D of pellagra
Dermatitis, Diarrhea, Dementia. If not treated, and even death.
Pharmacological use of niacin
Niacin is also used to treat lower triglycerides, and increase HDL-C. Combine with diet and exercise.
Excess intake of niacin
May caused by fleshings. Feel hot and skin turn red.
Pantothenic Acid
Part of coenzyme A, helps metabolism.
Food source of pantothenic acid
Meat, milk and many vegetables. And raw food contains better PA because heating, canning will reduce PA in food.
Needs of PA
AI: 5 mg per day
DV: 10 mg per day.
Upper level
No upper level. No know toxicity.
Absorption of PA
Absorbed in small intestine. And transport into body to make blood cells again.
Excretion
Excrete through urine.
Functions of PA
Coenzyme A, acyl carrier protein.(increase chain length)
Deficiency of PA
Rare. Experimentally induced.
Headache, muscle, GI tract substances.
Biotin
wide in food.
Food source
Whole grains, legumes, nuts, and eggs.
Microbial synthesis
Bacteria in large intestine also synthesize biotin.
Needs of biotin
AI: 30 micrograms
DV: 300 micrograms
Upper level of biotin
No upper level
Absorption of biotin
Absorbed in small intestine.
Storage
A little in muscle, liver, and brain.
Excretion
urine
Function of biotin
coenzyme in cab reactions, breakdown of some AA to use as energy. Carboxylation of acetyl-CoA to form malignly-CoA so fatty acids can be synthesized.
Deficiency of biotin
Rare. Genetic biotinase enzyme deficiency.
Consumptions of biotin
Anticonvulsant meds, matabsorption, excessive consumption of raw eggs.
Vitamins which have upper level
niacin, folate, vitamin B-6
Unique of B12
Only animal products contain. Only one contain cobalt.
