32 Vitamins, Minerals, and Trace Elements Flashcards
1
Q
Vitamins and Minerals
- Fat Soluble Vitamins
- Water Soluble Vitamins
- Energy
- Hematopoietic
- Ascorbate
- Macro-minerals
- Trace minerals
A
-
Fat Soluble Vitamins
- ADEK
-
Water Soluble Vitamins
-
Energy
- Thiamine (B1)
- Riboflavin (B2)
- Niacin (B3)
- Pantothenic acid (B5)
- Pyridoxine (B6)
- Biotin
-
Hematopoietic
- Folic acid
- B12
- Ascorbate (C)
-
Energy
-
Macro-minerals
- Calcium
- Phosphorous
- Magnesium
- Sodium
- Potassium
- Chloride
-
Trace minerals
- Zinc
- Iron
- Copper
- Selenium
- Chromium
- Manganese
- Iodine
- Fluoride
- Molybdenum
- Cobalt
- Vanadium
2
Q
Vitamin A (p.5-7)
- synthesized from/
- Critical component in/
- retinoic acid
- Good sources
- Too much
- Too little
A
- Retinol, also synthesized from plant caroteniods
- Critical electron shuttling component in vision
- Vitamin A (retinoic acid)
- Ligand for RXR (retinoic acid receptor) that helps regulate nuclear lipid receptor function, in turn controlling cell differentiation, growth, metabolism, inflammation
- Good sources – meats, eggs, carrots, cantalope
- Too much – can occur when used to treat acne, psoriasis. Induces birth defects, abortion
- Too little – night blindness, impairment of immune cell function, follicular keratosis
3
Q
Vitamin D (p.9)
- synthesized from/
- Ligand for/
- Works in concert with/
- Helps regulate/
- Good sources
- Too much
- Too little
A
- Hydroxycholecalciferol, also synthesized from cholesterol in skin exposed to UV light
- Ligand for a nuclear lipid receptor (Vitamin D receptor) that regulates gene expression
- Works in concert with parathyroid hormone to regulate expression of enzymes critical for calcium absorption from gut and calcium resorption from kidney
- Helps regulate immune cell function, insulin secretion, blood pressure
- Good sources - meat, fish, eggs, milk
- Too much – hypercalcemia
- Too little – Rickets, bone demineralization
4
Q
Vitamin K (p.11-12)
- required cofactor for/
- Vitamin K-dependent carboxylation occurs only on/
- Other
A
- required cofactor for a carboxylase that adds CO2 to glutamic acid, resulting in its conversion to gamma-carboxyglutamic acid (Gla)
- Vitamin K-dependent carboxylation occurs only on specific glutamic acid residues in a small number of proteins that use carboxy-glutamate in calcium binding
- Thrombin, blood clotting
5
Q
Thiamine (B1) (p.15)
- Critical cofactor for/
- Dehydrogenases/
- Transketolase/
- Good sources
- Too much
- Too little
A
- Critical cofactor for enzymes important in energetics and “information management” = genome function
- Dehydrogenases (pyruvate, ketoglutarate, ketoacid) that feed electrons into TCA cycle and mitochondria
- Transketolase, a critical pentose shunt enzyme, leads to formation of ribose-1-phosphate - a constituent of ATP, GTP, DNA, RNA
- Good sources – grains, legumes, nuts, leafy vegetables
- Too much – toxicity not observed
-
Too little – Beri-beri
- beri-beri could not be transmitted, prevented by an amine in husk of rice, later purified and named thiamine “vitamine”
6
Q
Riboflavin (B2) (p.16)
- available
- critical cofactor in /
- Good sources
- Too much
- Too little
A
- Vitamin B2, only dietarily available,
- critical cofactor in enzymes catalyzing electron transfer reactions
- Good sources – leafy plants, meats, grains, milk, eggs
- Too much – no recognized toxic effects
- Too little – Ariboflavinosis. Alcoholics, anorexics at risk
7
Q
Niacin (B3) (p.17)
- Serves as critical component of the/
- Too much
- Too little
A
- Serves as critical component of the e-transferring cofactors NAD, NADP
- Too much – no toxicity from dietary ingestion, only from over-supplementation: flushing, hepatotoxity from extended consumption of >500 mg/day
- Too little – pellagra, problem when diet depends too heavily on CHO sources such as corn. Manifested by dermatitis, hyperkeratosis, dementia, mild retardation
8
Q
Pantothenic Acid (B5)
- Fundamental cofactor for/
- Good sources
- Too much
- Too little
A
- Fundamental cofactor for acetylation and acyl transfer reactions - post-translational protein modification and fatty acid metabolism
- Good sources – fish, chicken, milk, yogurt, eggs, lentils, peas, mushrooms
- Too much – well tolerated, nausea and diarrhea when >1.2 gm/day
- Too little – Noted in malnourished POWs, numbness and burning sensation in feet relieved with pantothenic acid supplementation
9
Q
Pyridoxine (B6)
- available
- cofactor in
- Good sources
- Too much
- Too little
A
- Vitamin B6, only dietarily available,
- cofactor in enzymatic reactions: transamination, deamination, decarboxylation
- Good sources – fish, fowl, leafy vegetables, potatos, nuts
- Too much – sensory neuropathy from over-consumption of supplements (> 1 gm/day)
- Too little – Alcoholics at risk, but generally uncommon. Excessive associations made between low pyridoxine and incidence of various health problems, benefits of supplementation not strongly supported
10
Q
Biotin (p.22)
- Part of/
- synthesized by/
- Serves as cofactor for/
- Good sources
- Too much
- Too little
- Symptoms of biotin deficiency include/
A
- Part of “B complex” vitamins,
- synthesized by bacteria, yeast, molds, algae and some plants.
- Serves as cofactor for enzymes that carboxylate (add CO2) biomolecules
- Good sources – yeast, wheat bran, cooked eggs, liver
- Too much – no known toxicity
- Too little – observed to occur upon extended consumption of raw eggs (white) - promoting avidin-biotin complex formation and poor absorption
-
Symptoms of biotin deficiency include hair loss and red rash around eyes, nose, mouth, and genitalia.
- Neurologic symptoms include depression, lethargy, hallucination, and numbness and tingling of the extremities.
- The facial rash, together with an unusual facial fat distribution, have been termed the “biotin deficient face”
11
Q
Folic Acid (p.24)
- Mediates/
- methotrexate
- Good sources
- Too much
- hyperhomocysteinemia
A
- Mediates one-carbon transfer reactions that plays key role in purine, pyrimidine and methionine/homocysteine metabolism
- The anti-cancer drug methotrexate is a folate analog - inhibits metabolism and utilization
- Good sources - To limit neural tube defects (formerly 1/1000) 15 yr ago FDA mandated addition of 1.4 mg folic acid/kg to refined grain products also typically enriched with niacin, thiamin, riboflavin and iron (breads, pasta, rice, cereals). Also spinach, asparagus, lentils, beans
- Too much – no known toxicity
- 2007: The AHA decreed hyperhomocysteinemia is not a risk factor for CVD.
- The AHA recommends against use of folic acid and B vitamin supplements to reduce the risk of heart disease and stroke
12
Q
Vitamin B12 (p.25)
- cofactor for
- Good sources
- Too much
- Too little
- what increase risk
- Drug interaction
- The AHA does not recommend B vitamin supplements to reduce the risk of /
A
- Cobalamin, a cofactor for two enzymes
- methionine synthase (converts homocysteine to met), with met important for S-adenosyl methionine synthesis and downstrean DNA/RNA methylation
- L-methylmalonyl-CoA mutase catalyzes succinyl CoA formation, an intermediate critical in energy metabolism, heme biosynthesis
- Good sources – shellfish, fish, all meats, eggs, milk
- Too much – no known toxicity from supplementation
- Too little – causes pernicious anemia (2% incidence, >60 yr olds in US), with 10-15% people over 60 B12 deficient
- Gastritis, ulcers, autoimmune disorders affecting gut, alcoholism, strict vegan diet all increase risk
-
Drug interaction - B12 absorption from foodstuffs needs low pH in gastric compartment. Proton pump inhibitors (omeprazole) but not H2 blockers (Tagamet, Pepcid, Zantac) may induce B12 deficiency after 2-3 yr.
- Nitrous oxide (N2O) inhibits B12-dependent enzymes, can induce B12 deficiency
- The AHA does not recommend B vitamin supplements to reduce the risk of heart disease and stroke
13
Q
Ascorbic Acid (Vitamin C) (p.29)
- Humans, unlike most mammals cannot synthesize/
- antioxidant and a cofactor for/
- Good sources
- Too little
- what decrease Vit C (and E) levels
- Too little/
- Too much
A
- Humans, unlike most mammals cannot synthesize ascorbate
- antioxidant and a cofactor for collagen, norepinephrine and carnitine biosynthesis
- Good sources – fruits, tomatos, peppers, broccoli, potatoes
-
Too little – Scurvy.
- cured by eating oranges, lemons, limes.
- Symptoms include bleeding and bruising, hair and tooth loss, joint pain and swelling, all related to weakening of blood vessels, connective tissue and bone - all containing collagen
- Smoking, fast food decrease Vit C (and E) levels
- Too much – no apparent toxicity, plasma saturated at 400 mg/day
14
Q
Vitamin E
- synthesized by/
- Scavenges/
- E deficiency
- Good sources
- alpha-tocopherol blood levels in adults
A
- Tocopherol, also synthesized by gut bacteria
- Scavenges free radicals and inflammatory oxidants - limits secondary oxidation of fats in membranes and lipoproteins
- No known acute pathologic manifestations in E deficiency
- Good sources – oils, plant leaves, nuts, avocados
-
alpha-tocopherol blood levels in adults
- 27 % of European descent, 41% of African-Americans, 28% of Hispanic-Americans and 32% of “other” have < 20 mM Toc, a level identified because of possible increased risk for cardiovascular disease below this level
15
Q
Dietary Supplement Health and Education Act (DSHEA)
- “Draws the line” between/
- Dietary supplement
- who’s responsible for ensuring that ingredients are “safe”
- Dietary supplements can make structure/function claims that the product can/
- what constitutes an unapproved–and thus illegal–drug
A
- “Draws the line” between pharma- and nutriceuticals
- Dietary supplement - oral product containing a “dietary ingredient” (vitamins, minerals, herbs or other botanicals, amino acids, enzymes, organ tissues, glands)
- Manufacturer responsible for ensuring that ingredients are “safe”
-
Dietary supplements can make structure/function claims that the product can support the structure or function of the body
- “L-arginine helps build muscle mass“ (Nitro Rx)
- “The antioxidant vitamin E helps improve your sex life”
- “Resveratrol helps prevent heart disease”
- A product sold as a dietary supplement and promoted on its label or in labeling as a “treatment, prevention or cure” for a specific disease or condition” is an unapproved–and thus illegal–drug
