Vitamins

Question 1

Which are fat-soluble?

Answer 1

A, D, E, K

Question 2

Fat-Soluble v. Water-Soluble

Answer 2

Fat - co-absorbed w/ dietary fat; can become toxic if too much

Water - greater rate of turnover to greater likelihood of deficiency

Question 3

Vitamin A

Answer 3

• AKA retinol or retinoic acid (critical to electron shuttling in vision)
• Source: meats, eggs, carrots, cantalope
• Too Much: (from certain acne tx) –> birth defects or abortions, psoriasis
• Too Little: night blindness, impaired immune cell function, follicular keratosis

Question 4

Vit D

Answer 4

• AKA hydroxycholecalciferol
• Works w/ PTH to make enzymes for Ca+ reabsorption in kidney
• Source: meat, fish, eggs, milk AND made when cholesterol in skin is exposed to UV light
• Too Much: hypercalcemia
• Too Little: Rickets, bone demineralization

Question 5

Vitamin E

Answer 5

• AKA tocopherol
• Made by gut bacteria
• Scavenges free radicals and inflammatory oxidants
• No known manifestations of deficiency
• Sources: oils, plant leaves, nuts, avocados

Question 6

Vitamin K

Answer 6

• Required cofactor for carboxylase (adding CO2 to glutamic acid) including clotting factors (2, 7, 9, 10)
• Too Little: easy bruising

Question 7

Vitamin B1

Answer 7

• AKA thiamine
• Cofactor in dehydrogenases (that feed electrons into TCA cycle) and in transketolase –> ribose-1-phosphate which is important to ATP, GTP, DNA and RNA synthesis
• Sources: grains, legumes, nuts, leafy vegetables
• Too Little: Beri Beri

Question 8

Vitamin B2

Answer 8

• AKA riboflavin
• Cofactor for enzymes in electron transfer reactions
• Sources: leafy plants, meats, grains, eggs, milk
• Too Little: seen in alcoholics and anorexics; see ariboflavinosis

Question 9

Vitamin B3

Answer 9

• AKA Niacin
• Critical component of NAD and NADP
• Too Little: pellagra, dermatitis, hyperkeratosis, dementia, mild retardation

Question 10

Vitamin B5

Answer 10

• AKA Pantothenic Acid
• Cofactor for acetylation and acyl transfer (FA metabolism and protein modification)
• Sources: fish, chicken, milk, yogurt, eggs, lentils, peas, mushrooms
• Too Little: numbness and burning in feet (seen in POWs)

Question 11

Vitamin B6

Answer 11

• AKA Pyridoxine
• Cofactor in transamination, deamination, decarboxylation
• Sources: fish, fowl, leafy vegetables, potatoes, nuts
• Too Much: neuropathy if supplements

Question 12

Biotin

Answer 12

• Part of B complex vitamins
• Made by bacteria, yeasts, molds, algae, some plants
• Cofactor for carboxylation
• Too Little: (if eat raw eggs extensively –> forms complex that prevents biotin absorption) hair loss, red rash around eyes, nose and mouth (“biotin def face”), depression, lethargy, hallucinations, numbness/tingling

Question 13

Folic Acid

Answer 13

• Mediates 1 carbon transfer important in purine, pyrimidine and homocysteine metabolism
• Use in pregnancy to limit neural tube defects
• Sources: FDA mandated that refined grain products be enriched in folic acid + spinach, asparagus, lentils, beans

Question 14

Vitamin B12

Answer 14

• AKA Cobalamin
• Cofactor in 2 important reactions
  
  • 1- methionine synthase - makes met which is important in downstream methylation of DNA
  • 2- Succinyl CoA formation
• Sources: shellfish, meats, eggs, milk
• Too Little: pernicious anemia
• Absorption can be impaired if on PPIs

Question 15

Vitamin C

Answer 15

• AKA ascorbic acid
• Anti-oxidant and cofactor for collagen, NE and carnitine synthesis
• Sources: fruits, tomatoes, peppers, broccoli, potatoes
• Too Little: scurvy (bleeding, bruising, hair loss, joint pain/swelling, weak blood vessels, connective tissue and bone)
• Smoking and fast food dec Vit C