Nutrition 2 lecture

Question 1

What is a deficiency?

Answer 1

below what is required for an individual, often resulting in a well-described disease associated with the
deficiency.

Does not require only inadequate intake

Question 2

Insufficiencies?

Answer 2

occur when intake is below what is optimal for health, making an individual susceptible to disease

Question 3

Vitamin D2?

Answer 3

(ergocalciferol)

Question 4

Vitamin D3 ?

Answer 4

(cholecalciferol)

Question 5

Calcidiol?

Answer 5

(25-hydroxy vitamin D): storage form in liver

Question 6

Calcitriol?

Answer 6

active vitamin D (1,25-dihydroxy vitamin D); formed in kidney in response to PTH Function

Question 7

Purpose of vitamin D?

Answer 7

• GI tract: induces synthesis of Ca2+ binding proteins and promotes Ca2+ absorption
• Kidneys: stimulates reabsorption of Ca2+ and phosphate
• Bone: osteoclast activation → bone resorption

Question 8

What can cause Vitamin D deficiency and what are the effects?

Answer 8

Impaired availability secondary to inadequate dietary intake, fat malabsorption, lack of sunlight
resistance to vitamin D metabolites

Result:

• Childhood rickets (skeletal abnormalities)
• Adults osteomalacia (fewer deformities)
• Delayed growth
• Pain in the spine, pelvis and legs
• Muscle weakness
• Bowed legs

Question 9

is Calcium and Vitamin D supplementation important?

Answer 9

• Important for proper bone formation, nerve function, muscle function and strength
• they work together
• Vitamin D3 > Vitamin D2
• Calcium citrate than carbonate is better but more expensive

Question 10

Thiamine B1, what does it do and what are effects of deficiencies?

Answer 10

Coenzyme form: thiamine pyrophosphate (TPP)
TPP catalyzes conversion of pyruvate to acetyl CoA mediated by pyruvate dehydrogenase

Effects:
Wernicke-Korsakoff syndrome:
-Wernicke’s encephalopathy : (acute) ataxia, nystagmus, ophthalmoplegia, confusion
-Korsakoff’s syndrome : (chronic) psychosis, confabulation

Dry beriberi : muscle wasting, partial paralysis
Wet beriberi : peripheral edema, cardiac failure

Question 11

Riboflavin (B2)what does it do and what are effects of deficiencies?

Answer 11

Coenzyme forms: FAD/FMN
Coenzyme for several dehydrogenases

Effects:
-Deficiency is ariboflavinosis
Usually undetected, accompanied by other deficiencies, malabsorption issues
-clinical manifestation: alot of “itis”, sore throat

Question 12

Niacin (B3) what does it do and what are effects of deficiencies?

Answer 12

Coenzyme forms: NAD(H) and NADP(H)

Effects:

• Pellagra: Diarrhea, Dementia, Dermatitis, Death (4Ds)
• Malnutrition from alcoholism, bariatric surgery, AN, or malabsorption diseases Clinical manifestations:
• Hartnup disease: impaired AA absorption from intestines and reabsorption in kidneys → tryptophan deficiency → niacin deficiency

Question 13

Pantothenic Acid (B5) what does it do and what are effects of deficiencies?

Answer 13

Synthesis of coenzyme A (CoA):

Deficiency from extreme starvation

Effects:
Dermatitis, numbness, paresthesia and dysesthesias (“burning feet syndrome”)

Question 14

Pyridoxine (B6) what does it do and what are effects of deficiencies?

Answer 14

Converted to pyridoxal phosphate in the body

Effects: Sideroblastic anemia (cannot incorporate iron into heme)

Dermatitis, glossitis, cheilosis/stomatitis, irritability, confusion

Question 15

Biotin (B7) what does it do and what are effects of deficiencies?

Answer 15

Cofactor for carboxylation enzymes:

Acetyl-CoA carboxylase (ACC)

Pyruvate carboxylase (PC)

Propionyl CoA carboxylase (PCC)
Methylcrotonyl CoA (MCC) 

Deficiency from eating raw eggs

Question 16

Folic Acid (B9)

Answer 16

-Tetrahydrofolate is a coenzyme for 1-carbon transfer/methylation reactions, e.g., thymidylate synthase (de novo pyrimidine synthesis)

Effects:
-Folate pool quickly depleted in alcoholics and pregnancy

Question 17

Cobalamin (B12)

Answer 17

• Converted to coenzymes methyl- or deoxyadenosyl cobalamin
• Deficiency from:

Pernicious anemia (most common cause)

Chronic pancreatitis

Long-term total vegetarian diet

Resection of terminal ileum

Question 18

Ascorbic Acid (Vitamin C)?

Answer 18

-Collagen synthesis, neurotransmitter synthesis (dopamine → norepinephrine), fatty acid transport, prostaglandin metabolism, nitric oxide synthesis

Deficiency:

• Dietary deficiency from: devoid of citrus fruits and green vegetables
• Clinical manifestations: Scurvy

Question 19

Vitamin E?

Answer 19

Essential for normal fetal and childhood development, antioxidant free radical scavenger

Deficiencies are rare: fat malabsorption

Question 20

Vitamin K?

Answer 20

Essential factor for proper blood clotting

Deficiency leads to bleeding issues, osteoporosis

Interactions with blood thinners such as warfarin

Question 21

Vitamin A?

Answer 21

Main functions: vison and maintenance of epithelium

-Preformed vitamin A

Retinol

Retinoic acid

Retinal

Retinyl esters

Stored in liver as retinol

Deficiency happens from severe malnutrition:
night blindness and infections