B. Nutrition and Supporting Sciences

Question 1

Nutrient intake estimated to meet the requirement of HALF the individuals in a group is called:

AI?

RDA?

EAR?

UL?

Answer 1

EAR (Estimated Average Requirement)

Note: actually represents an estimated median requirement.

Question 2

This is set to meet the needs of almost all (97-98%) individuals in a group.

RDA?

DRI?

EAR?

Answer 2

RDA

Question 3

• _____, also known as, Vitamin B1
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?
• Half life?

Answer 3

• Thiamin, also known as, Vitamin B1
• No UL
• RDA (needs based on 0.5mg/1000kcal)
  
  • Females: 0.9-1.1mg
  • Males:0.9-1.2mg
• Deficiency
  
  • Rare but occasionally occur in alcoholics b/c poor intake & impaired absorption (s/s:confusion, polyneuritis, & nystagmus
  • Extreme deficiency=beriberi or wernicke-korsakoff syndrome, muscle weakness, fatigue, irritability, memory loss
  • “wet” or “dry” beri beri affecting heart and nerves
• Important b/c the phosphorylated form (TPP) impt co-factor for enzymes for CHO, pro, fat metabolism
• Highest concentrations in skeletal muscles, liver, heart, kidneys, & brain
• Found in legumes, pork, brown rice, whole grains
• Half life of 10-20 days

Question 4

• Niacin, a type of __ vitamin
• Is there an upper limit? Yes or No
  
  • ​If yes, explain what can happen.​
• Is there an RDA set or AI? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in body?
• Food sources?
• Half life?

Answer 4

• Niacin is a type of B vitamin (nicotinic acid)
• Has UL [30-35mg/day] adolescents/adults
  
  • For dz management lowering cholesterol (can even be up to 500mg-12mg)
  • Large doses can cause liver damage, peptic ulcers, skin rashes
• RDA (6.6mg/1000kcal)
  
  • Males: 12-16mg
  • Females: 12-14mg
• Severe deficiency (pellegra) leads to 3 D’s
  
  • dermatitis, diarrhea, & dementia
• Part of coenzymes NADH/NADPH fxn as central electron carriers for CHO, FA, and pro metabolism
• Made from tryptophan and can be used to make serotonin thus, a tryptophan deficiency can lead to serotonin deficiency.
  
  • ​60mg tryptophan= 1mg niacin
  • Most stable of all vitamins
• Stored to limited extent
• Found in liver, meats, fish, whole/enriched grains
• Half-life 15-30mins

Question 5

• _____, also known as vitamin B2
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?
• Half life?

Answer 5

• Riboflavin, also known as vitamin B2
• No UL
• RDA (0.6mg/1000kcal)
  
  • Males: 0.9-1.3mg
  • Females: 0.9-1.1mg
• Signs of deficiency: photophobia, loss of visual acuity, burning/itchy eyes, cheilosis, glossitis, seborrheic dermatitis, chapped lips, fissures in corners of mouth
• Help w/ B6, folate, niacin, & vit K to their active forms. Fxn as a coenzyme in redox rxn (FMN/FAD)–intracellular metabolism
• Help w/ biosynthesis of niacin from tryptophan.
  
  • Helps maintain body tissue, assist RBC formation
• Little stores
• Found in milk, dark greens, cheese, cereals, meats, eggs, mushrooms.
• Absorbed in ~1hr

Question 6

• _____, also known as vitamin B6
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?

Answer 6

• Pyridoxine, also known as vitamin B6
• Has UL (80-100mg)
  
  • Cases of peripheral neuropathy, dermatoses [long term megadoses]
  • progressive ataxia, altered sense of touch, temp/pain (sensory deprivation)
• RDA
  
  • Females: 1.0-1.5mg
  • Males: 1.0-1.7mg
• Deficiency= rare but may be precipitated by some medications (isoniazid-TB)
• Importance: the metabolically active form is “pyridoxal phosphate” or PLP
  
  • PLP fxn as coenzyme in many aspects of AA metabolism; also in hemoglobin synthesis
  • Body’s need is in direct proportion w/ amount of protein in diet
• Limited stores in body
• Found in liver, meats, brewer’s yeasts, nuts, seeds, beans, potatoes

Question 7

• ____is a type of B vitamin
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?

Answer 7

• Folate (folic acid) is a type of B vitamin
• Has UL of 800-1000ug
  
  • Rare instances of s/s
• RDA
  
  • Males & Female: 300-400mcg
• Deficiency: poor growth, macrocytic anemia, glossitis
• Essential role in normal cell division, critical in embryogenesis. Also for formation/maturation of both RBC/WBC. **periconceptal supplementation can reduce risk for neurotube defects when added to enrichment mix.
  
  • Note: supplemental folate can mask effects of vitamin B12 deficiency
• ​Stored primarily in liver
• Found in foods such as legumes, soybeans, green leafy veggies, enriched grains

Question 8

• _____, also known as cobalamin
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set?
  
  • If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?

Answer 8

• Vitamin B12 is also known as cobalamin
• No UL
• RDA
  
  • Males/Females: 1.8-2.4 mcg
• Deficiency= pernicious anemia
  
  • ​Occur in older adults b/c poor intrinsic factor; 2/2 gastrectomy, SBR, inherited def.
• Impt as a coenzyme for DNA metabolism for growth and division of all cells, RBC formation
  
  • Absorbed in the terminal ileum of the SI & requires intrinsic factor
  • Necessary to convert folate to active form
  • Can be stored up to 10 years
• Found in meats, clams, oysters, milk
  
  • **vegetarians often need supplements

Question 9

• ____is a type of B vitamin
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?

Answer 9

• Biotin is a type of B vitamin
• No UL
• No RDA, only AI set
  
  • Males/Females: 20-30mcg
• Deficiency is rare however, symptoms are:
  
  • Lenier’s dermatitis
  • glossitis
  • anorexia
  • nausea
• Fxn as coenzyme in synthesis of fat, glycogen, & some amino acids
• Can be obtain from foods and from gut microbial metabolism
  
  • egg yolk, liver, dried beans, mushrooms

Question 10

• ____is a type of B vitamin
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?

Answer 10

• Pantothenic acid is a B vitamin
• No UL
• No RDA, only AI
  
  • Males/females: 4-5mg
• Deficiency is rare, seen only in severely malnourished subjects
• Integral part of acetyl coA, thus necessary for metabolism of FA, CHO, and AA.
• Synthesis/oxidation of FA

Question 11

• ____is a water soluble vitamin also known as ascorbic acid.
• Is there an upper limit? Yes or No
  
  • If yes, explain what happens
• Is there an RDA/AI set? If so, what are the ranges for males/females?
• What happens if there is a deficiency?
• Importance of this vitamin?
• Found where in the body?
• Food sources?

Answer 11

• Vitamin C, also known as ascorbic acid
• Has UL 1800-2000mg
  
  • excessive= GI disturbances, kidney stones, excess iron absorption
• RDA
  
  • Females: 45-75mg
  • Males: 45-90mg
  • Smokers need additional 35mg/day
• Deficiency= scurvy, easy bone fractures, poor wound healing, bleeding gums w/ loose teeth
• Enhances iron absorption from gut by reducing ferric iron to ferrous iron
• Fxn as antioxidant by reacting w/ free radicals
• Aids in collagen formation

Question 12

Which water soluble & fat soluble vitamins only have AI recommendations?

Answer 12

Water-soluble: biotin & pantothenic acid

Fat-soluble: vitamin K

Question 13

This water-soluble vitamin is a hexose derivative, synthesized in most animals but not in humans from glucose and galactose.

Answer 13

Vitamin C

Question 14

Water-soluble vitamins are only stored in the body for a brief period of time. Which vitamin is an exception and stored in the liver?

Answer 14

Vitamin B12

Question 16

Folic acid (B9) works with vitamins ____ and ____ to hlep the body digest and utilize proteins and to synthesize new proteins when they are needed.

Answer 16

Vitamins B12 and C

Question 17

Deficiency in this vitamin can lead to

“megaloblastic anemia” and neural tube defects.

Answer 17

Folate (folic acid)

Question 18

What test can help identify vitamin B12 deficiency?

Answer 18

Schillings test