B Vitamins

Question 1

The B Vitamins: Coenzymes

Answer 1

Coenzymes: small molecules that work with enzymes to promote their activities
- help the body use energy- yielding nutrients
- B vitamins are components in coenzymes
- help cells multiply
- assist enzymes in performing molecular conversions

Question 2

Deficiency in Thiamin

Answer 2

Beriberi disease

Question 3

Deficiency in niacin B vitamin

Answer 3

Pellagra

Question 4

Thiamin (B1) Function

Answer 4

• critical role in energy metabolism in all cells
• necessary for normal nerve and muscle functioning

Question 5

Thiamin Deficiency

Answer 5

-Deficiency: Wernicke-Korsakoff syndrome (associated with alcoholism)
S&S: mental confusion, vision problems, coma, hypothermia, low blood pressure, and lack of muscle coordination
Beriberi: (edema or muscle wasting), anorexia and weight loss, neurological disturbances, muscular weakness, heart enlargement and failure

Question 6

Thiamin deficiency and toxicity

Answer 6

Toxicity: NONE

Question 7

Thiamin Food Sources

Answer 7

pork, whole grain or enriched bread and cereals; small amounts in nearly all nutritious foods

Question 8

Riboflavin (B2) Function, Deficiency, in foods, effects of light

Answer 8

Serves as a coenzyme in energy metabolism
- deficiency causes cracks in corners of mouth and sore throat, inflammation of eyelids; sensitivity to light
- no toxicity reported
- foods: milk products; enriched, fortified, or whole-grain products, liver, green vegetables
- effects of light: light sensitive, but heat stable

Question 9

Niacin (B3) precursor is dietary tryptophan an amino acid

Answer 9

Function: part of coenzymes used in energy production.
Deficiency symptoms: Pellegra (diarrhea, dermatitis, and dementia)
Toxicity symptoms: Niacin flush, liver damage, impaired glucose tolerance)
Food sources: milk, eggs, meat, poultry, fish, whole-grain and enriched breads and cereals, nuts, and all protein-containing foods
- body can produce niacin from tryptophan. UL: 35mg NE
- Niacin (nicotinic acid) used as a medication
Large doses lower blood cholesterol. used in atherosclerosis treatment

Question 10

Biotin

Answer 10

Function: part of a coenzyme used in energy metabolism
Deficiency Symptoms: Skin, rash, hair loss, neurological disturbances. Intravenous feeding, avidin
Toxicity symptoms: none reported
Food sources: widespread in foods; GI bacteria synthesis

Question 11

Pantothenic acid

Answer 11

Function: part of a coenzyme used in energy metabolism
Deficiency Symptoms: Digestive and neurological disturbances
Toxicity Symptoms: None reported
Food sources: Widespread in foods

Question 12

Vitamin B6

Answer 12

Function: Part of coenzymes used in amino acid and fatty acid metabolism. macronutrient metabolism. synthesis of hemoglobin and neurotransmitters. release stored glucose from glycogen.
Deficiency Symptoms: scaly dermatitis, depression, confusion, convulsions, anemia. irritability, weakness
Toxicity: Nerve degeneration, skin lesions (results from supplement use)
Food Sources: meats, fish, poultry, potatoes, legumes, non-citrus fruits, fortified cereals, liver, soy products. heat sensitive

Question 13

Folate, alcohol, and drugs: negative impact on folate status

Answer 13

• Alcohol: impairs absorption, increases excretion
• Medications: aspirin, oral contraceptives, and anticonvulsants
• smoking

Question 14

Folate

Answer 14

Function: Activates Vitamin B12 helps synthesize DNA for new cell growth
Deficiency Symptoms: Anemia; smooth, red tongue; mental confusion; elevated homocysteine
Toxicity: masks vitamin B12 deficiency
Food sources: fortified grains, leafy green veg, legumes, seeds, liver
Folate and neural tube defects (NTD)
- prevented by supplements in early pregnancy
- UL: 1000 ug/day from fortified foods and supplements

Question 15

Vitamin B12

Answer 15

Function: Activates folate; helps synthesize DNA for new cell growth; protects nerve cells
- cell division: accepts carbon groups from folate, regenerating folate’s active form. Macrocytic anemia
- the nervous system: maintains nerve fibers.
Deficiency symptoms: anemia; nerve damage and paralysis
Toxicity: None reported
Foods: foods derived fro animals, fortified cereals (deficiency in vegans)
Absorption: requires intrinsic factor. atrophic gastritis and pernicious anemia

Question 16

Relationship between folate and vit B12

Answer 16

the term folate refers to two form of the B vitamins: naturally occurring folates in foods and folic acid
- B12 stands by to accept carbon groups from foalte as folate removes them from other compounds. the passing of these carbo groups from folate to vitamin B12 regenerates the active form of folate so that it can continue its dismantling tasks. in the absence of vit B12, folate ist rapped in its inactive metabolically useless form.
- when folate is trapped or there is a deficiency of folate cells that are growing most rapidly (the blood cells) are affected/