(P) Lec 2: Vitamins (Part 2) Flashcards by Kchianna Lauren Coronel

Vitamins are:
1. (Organic/Inorganic) molecules
2. (Cofactors/Coenzymes) for many reactions
3. (Essential/Non-essential), meaning they are supplied by the diet as they cannot be synthesized in the body

Organic
Cofactors
Essential

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TOF: Some bacteria can synthesize vitamins

True

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What are the 4 fat-soluble vitamins?

A, D, E, K

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Defined as the inadequate intestinal absorption and activity levels of the vitamins

Vitamin Deficiency

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What 2 terms are also related to inadequate absorption and decreased intake of vitamins?

Vitamin insufficiency
Vitamin dependency

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A condition wherein there is abnormal increased metabolism of vitamins requiring a high supply of it

Note: Can also be caused by inadequate intake and absorption of vitamins

Dietary deficiency

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Dietary deficiency is also known as?

Hypovitaminosis

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Vitamins are required in what amount only?

Trace amounts

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In the past, what was believed to prevent scurvy and rickets?

Note: 2 answers

Scurvy (Vit. C deficiency) - Lime juice
Rickets (Vit. D deficiency) - Cod liver oil

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These vitamins are soluble in lipids but not in aqueous solutions
They are not secreted but rather stored in the body

Fat-soluble vitamins

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Fat-soluble Vitamins

Obtained from meats and beta-carotenes in plants
Important for vision, growth and health of skin and mucous membranes, and the development of teeth, soft, and skeletal tissue

Vitamin A

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Fat-soluble Vitamins

This is stored in the liver and is transported and complexed to RBP and transerythrin
A deficiency of this can lead to nyctalopia (night blindness) and later on total blindness caused by malabsorption, impaired liver function, and protein malnutrition

Vitamin A

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Fat-soluble Vitamins

The hypervitaminosis state of this can lead to liver damage
The recommended daily allowance (RDA) is 900 ug/male and 700 ug/female
Measurement is done through retinol measurement using HPLC

Vitamin A

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Fat-soluble Vitamins

Beta-carotenes (pro vitamin A) are converted by the liver enzymes into what?

Retinol

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Fat-soluble Vitamins

Retinol is oxidized in the rods of the eye to form what chemical that allows for dim-light vision?

Rhodopsin

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Fat-soluble Vitamins

What are the 2 transport proteins of Vitamin A?

Retinol-binding protein (RBP)
Transerythrin

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Fat-soluble Vitamins

In cases of Vitamin A hypervitaminosis, this can be measured to check for toxicity using the HPLC method

Retinyl ester

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Fat-soluble Vitamins

Vitamin A Compounds (match with their functions):
1. Antioxidant
2. Steroid hormone (for growth and differentiation)
3. Visual cycle
4. Glycoprotein synthesis
5. The final product (steroid hormone)

A. Retinyl phosphate
B. B-carotene
C. Retinoic acid
D. Retinol
E. Retinal

(B) B-carotene
(D) Retinol
(E) Retinal
(A) Retinyl phosphate
(C) Retinoic acid

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Fat-soluble Vitamins

Is synthesized in skin exposed to sunlight (cholecalciferol from 7-dehydrocholesterol)
It requires bile for its absorption in the GIT and is stored in the liver
Obtained from irradiated foods and commercially prepared milk

Vitamin D

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Fat-soluble Vitamins

What are the 2 major forms of Vitamin D?

Ergocalciferol
Cholecalciferol

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Fat-soluble Vitamins

What is the most active metabolite of vitamin D?

1,25 (OH)2 D3 (calcitriol)

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Fat-soluble Vitamins

This is important for the intestinal absorption of calcium and PO4
It stimulates the bone to increase mobilization of calcium and PO4
Important for the proapoptic effect

Vitamin D3 (calcitriol)

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Fat-soluble Vitamins

The recommended daily amount is 15-20 ug/day
A deficiency of this can result in a failure to calcify cartilage at the growth plate leading to rickets in infants and osteomalacia in adults (demineralization of bone matrix)
Is measured through RIA or HPLC in conjunction with competitive protein binding

Vitamin D

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Fat-soluble Vitamins

Elevated levels of this vitamin can be seen in:
- Hyperparathyroidism and hypophosphatemia
- Pregnancy

Vitamin D

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# Fat-soluble Vitamins Elevated levels of this vitamin can lead to: - Hypercalcemia - Hypercalciuria - Irreversible renal and cardiac damage

Vitamin D

# Fat-soluble Vitamins What are the 2 forms of vitamin D most commonly measured?

1. 25 (OH) D3 (calcidiol) 2. 1,25 (OH)2 D3 (calcitriol)

# Fat-soluble Vitamins - An antioxidant in cells that prevents the oxidation of unsaturated fatty acids - It protects the erythrocyte membrane from oxidative stress - Is absorbed in the jejunum, stored in the liver and tissues, and excreted in the feces

Vitamin E

# Fat-soluble Vitamins - Can be obtained from green vegetables, vegetable oil, egg yolk, bread, dairy products, peas, and beans - A defense against harmful oxidation that causes disease and aging (e.g. Myra)

Vitamin E

# Fat-soluble Vitamins - A deficiency of this may result to hemolytic anemia, RBC fragility, and ataxia - Its deficiency can be caused by low intake of vegetable oil or other unsaturated fats and fat malabsorption due to CF or abetalipoproteinemia - Infants with chronic cholestasis along with a deficiency of this vitamin can have neurologic function loss

Vitamin E

# Fat-soluble Vitamins - High doses of this have no known intoxication (the higher, the better) - The recommended daily amount is 15 mg/d - Is measured through the measurement of alpha-tocopherol using HPLC

Vitamin E

# Fat-soluble Vitamins This is considered as the most potent isomer of Vitamin E

Tocopherol (alpha-tocopherol)

# Fat-soluble Vitamins - This is essential for the synthesis of zymogens for blood clotting - Important for vitamin-dependent factors such as factor 2, 7, 9, 10, and protein C and S

Vitamin K

# Fat-soluble Vitamins - The dietary form is absorbed in the ileum while 50% of it can come from intestinal bacteria - Obtained from green fruits and vegetables, tomatoes, soy, beef, liver, yolks, wheat, and pork

Vitamin K

# Fat-soluble Vitamins - The adequate intake is 120 ug/d for males and 90 ug/d for females - Its deficiency may be caused by antibiotic therapy or antagonists such as Warfarin and Coumadin

Vitamin K

# Fat-soluble Vitamins - Large doses of this are not common however in newborns, it could result to hyperbilirubinemia - PT and PTT are available to measure the clotting factor activities of the body

Vitamin K

# Fat-soluble Vitamins Vitamin K deficiency can lead to what?

Hemmorhagic loss

# Fat-soluble Vitamins TOF: Vitamin E is absorbed in the ileum

False (jejunum) Note: It is Vitamin K that is absorbed in the ileum

# Fat-soluble Vitamins In vitamin D, cholecalciferol is produced from what substance upon sunlight exposure?

7-dehydrocholesterol

# Fat-soluble Vitamins In Vitamin D deficiency, which condition is common in infants and which is for aduts? Note: 2 answers

1. Infants - rickets 2. Adults - osteomalacia

# Fat-soluble Vitamins What form of vitamin D is this? 1, 25 (OH) D3

Calcitriol

# Fat-soluble Vitamins What form of vitamin D is this? 25 (OH)2 D3

Calcidiol

# Fat-soluble Vitamins Vitamin K originated from what German word?

Koagulation

- These are soluble in aqueous solutions and are used as cofactors by many enzymes - These are not stored in the body but rather excreted through the urine

Water-soluble vitamins

Toxic accumulation is less likely in water or fat-soluble vitamins?

Water (because it is excreted in the urine)

# Water-soluble Vitamins - This is the first vitamin B variant identified - Part of the coenzyme, thiamine pyrophosphate (TPP) - Absorbed in the intestines and excreted in urine

Thiamine (Vit. B1)

# Water-soluble Vitamins - A chronic deficiency of it may result to beriberi (both wet and dry) - Deficiencies may be due to chronic alcoholism, decreased intake, impaired absorption, and increased release in urine

Thiamine (Vit. B1)

# Water-soluble Vitamins Thiamine pyrophosphate (TPP) is a coenzyme that aids in the decarboxylation of what acids?

Alpha-keto Carboxylic Acids

# Water-soluble Vitamins Symptoms of Wet or Dry Beriberi (Vit. B1 deficiency)? Emaciation, wrist drop, and aphonia

Dry

# Water-soluble Vitamins Symptoms of Wet or Dry Beriberi (Vit. B1 deficiency)? Dyspnea, orthopnea, edema, Wernicke's syndrome, and ophthalmoplegia

Wet

# Water-soluble Vitamins - Made of the sugar alcohols, ribitol and flavin - It works with other B vitamins to promote healthy growth and tissue repair - Helps release energy from carbohydrates

Riboflavin (Vit. B2)

# Water-soluble Vitamins These 2 coenzymes that contain riboflavin (vit. B2) are important for redox reactions in the body, what are those?

1. Flavin adenine dinucleotide (FAD) 2. Flavin mononucleotide (FMN)

# Water-soluble Vitamins - This is important for healthy RBC production - The recommended daily amount is 1.7mg - Is absorbed in the small intestine and excreted in urine - Deficiency may be due to other nutritional deficiencies, alcoholism, chronic diarrhea, and malnutrition

Riboflavin (Vit. B2)

# Water-soluble Vitamins - Important for the maintenance of healthy brain function, RBC formation, protein breakdown, and antibody synthesis - Is needed for amino acids and protein metabolism

Pyridoxine (Vit. B6)

# Water-soluble Vitamins What are the 3 forms of Pyridoxine (Vit. B6)?

1. Pyridoxine 2. Pyridoxal 3. Pyridoxamine

# Water-soluble Vitamins Among the 3 forms of Pyridoxine (Vit. B6), which are present in plants and which are in animals? Note: 2 answers

1. Plants - Pyridoxine 2. Animals - Pyridoxal and Pyridoxamine

# Water-soluble Vitamins - This is a cofactor and can be obtained in meat, poultry, fish, potatoes, vegetables, and dairy products - The recommended daily amount is 2mg (adults) - Is absorbed in the intestine and excreted in urine as metabolites

Pyridoxine (Vit. B6)

# Water-soluble Vitamins - Deficiencies are associated with hyperhomocysteinemia - High doses could result to peripheral neuropathy which are caused by increased intake of protein

Pyridoxine (Vit. B6)

# Water-soluble Vitamins - The generic name for nicotinic acid and nicotinamide - Part of NAD and NADP - Absorbed in the intestine and excreted in urine as metabolites

Niacin (Vit. B3)

# Water-soluble Vitamins This dietary amino acid is the one converted into niacin

Tryptophan

# Water-soluble Vitamins - Deficiency of this can result to Pellagra-dermatitis, muscle fatigue, diarrhea, loss of appetite, Cassal's necklace, and dementia - Deficiencies may be caused by chronic alcoholism and a corn and molasses diet (it decreases tryptophan) - Can be found in meats, rice, and whole grains

Niacin (Vit. B3)

# Water-soluble Vitamins - Is converted into 4-phosphopantetheine that binds either a serum acyl carrier or coenzyme A - Needed for energy production and synthesis of glucose and cholesterol - Can be found in whole grains, vegetables, eggs, liver, heart, yeast, and muhsrooms

Pantothenic Acid (Vit. B5)

# Water-soluble Vitamins Pantothenic acid came from the Greek word "pantos" which means what?

Everywhere

# Water-soluble Vitamins - Serves as a coenzyme for enzymes that transport carboxyl units in tissue - Plays an integral role in gluconeogenesis, lipogenesis, and fatty acid synthesis

Biotin

# Water-soluble Vitamins - This is synthesized in the gut by the bacteria present there - Its deficiency may be a result of ingestion of large amounts of avidin Note: Its deficiency is noted for patients receiving long term parenteral nutrition and infants with genetic defects of carboxylase and biotinidase enzymes

Biotin

# Water-soluble Vitamins The deficiency of biotin is noted for patients receiving long term parenteral nutrition and infants with genetic defects of what 2 enzymes?

Carboxylase and Biotinidase

# Water-soluble Vitamins - Important for the formation and stabilization of collagen, hormone synthesis, infection resistance, and for cuts - It increases the absorption of iron in the upper small intestine

Ascorbic acid (Vitamin C)

# Water-soluble Vitamins - A deficiency (hypovitaminosis) of this can lead to scurvy - It is characterized by hemorrhagic disorders, weakness, anemia, bruising, bleeding and swollen gums, impaired wound healing, and loose teeth

Ascorbic acid (Vitamin C)

# Water-soluble Vitamins - Its hypervitaminosis state may be caused by an addiction to this vitamin or diarrhea - Can be found in citrus fruits, green peppers, strawberries, tomatoes, broccoli, and sweet and white potatoes

Ascorbic acid (Vitamin C)

# Water-soluble Vitamins - The assay for measurement uses 2,4-dinitrophenylhydrazine - The recommended daily amount is 60mg

Ascorbic acid (Vitamin C)

# Water-soluble Vitamins What fruit has the highest level of vitamin C?

Guava

# Water-soluble Vitamins - A coenzyme for hematopoiesis, fatty acid metabolism, and CNS maintenance - Absorption happens in the ileum with the help of intrinsic factors produced by the stomach's parietal cells

Cobalamin (Vit. B12)

# Water-soluble Vitamins - Can be found in animal products (meat, egg, milk, poultry, and shellfish) since they have the process of intestinal microbial synthesis - Has a large group of cobalt-containing compounds

Cobalamin (Vit. B12)

# Water-soluble Vitamins - Its deficiency may result to pernicious or megaloblastic anemia due to a lack of the intrinsic factor and a neurologic disorder

Cobalamin (Vit. B12)

# Water-soluble Vitamins TOF: Vegetarians are more prone for Cobalamin (Vit. B12) hypervitaminosis

False (hypovitaminosis; it is sourced from meat)

# Water-soluble Vitamins What are the 3 forms of Cobalamin (Vit. B12)?

1. Hydroxocobalamin 2. Methylcobalamin 3. Deoxyadenosylcobalamin

# Water-soluble Vitamins What are the 2 active forms/cofactors of cobalamin (vit. B12)?

1. Methylcobalamin 2. Deoxyadenosylcobalamin

# Water-soluble Vitamins - A coenzyme in various one-carbon transfer reactions - Is absorbed in the jejunum - Is synthesized by bacteria in the intestine

Folate

# Water-soluble Vitamins - Can be sourced from green and leafy vegetables, fruits, organ meats, and yeast - Boiling vegetables could decrease the vitamin levels of this

Folate

# Water-soluble Vitamins - Its deficiency may result to megaloblastic anemia caused by alcoholism, malabsorption syndrome, carcinoma, and liver disease - An increase of this during pregnancy could reduce the incidence of fetal neural tube defects

Folate

# Water-soluble Vitamins This is a drug that interferes with folate absorption which may result to decreased levels

Phenytoin (Dilantin)

# Water-soluble Vitamins Biotin deficiency may be a result of ingestion of large amounts of what?

Avidin (a biotin-binding protein)

# Water-soluble Vitamins These 2 vitamins are synthesized by bacteria found in the intestines

Biotin and Folate

# Water-soluble Vitamins Its coenzyme is Thiamine Pyrophosphate (TPP)

Vitamin B1

# Water-soluble Vitamins Its coenzyme is Flavin Adenine Dinucleotide (FAD) and Flavin Mononucleotide (FMN)

Vitamin B2

# Water-soluble Vitamins Its coenzyme is Nicotinamide adenine dinucleotide (NAD) and Nicotinamide adenine dinucleotide phosphate (NADP)

Niacin

# Water-soluble Vitamins Its coenzyme is either Serum Acyl Carrier or Coenzyme A

Vitamin B5

# Water-soluble Vitamins Its coenzymes are those that transport carboxyl units in tissue

Biotin

# Water-soluble Vitamins TOF: All water soluble vitamins are excreted in urine and stool

False (urine only)

# Water-soluble Vitamins What 2 sugar alcohols make up Riboflavin?

Ribitol and Flavin

# Water-soluble Vitamins Pyridoxine (Vit. B6) deficiency is associated with what specific condition?

Hyperhomocysteinemia