W10 Vitamins- Niacin (B3), Pantothenic Acid (B5) Flashcards
What disorder is associated with niacin deficiency?
A. Beri beri
B. Pellagra
C. Scurvy
B. Pellagra
Pellagra is known clinically by the ‘4Ds’:
- Dermatitis
- Dementia
- Diarrhea
- Death
FUN FACT!! Pellagra is the Italian phrase for “dry skin” because niacin deficiency presents with dermatitis like symptoms.
\_\_\_\_\_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_\_\_\_ are niacin containing compounds found in food and are coenzymes in metabolic reactions. A. NAD, NADP B. FAD, FADH C. None of the above
A. NAD (Nicotinamide Adenine Dinucleotide), NADP (Nicotinamide Adenine Dinucleotide Phosphate)
Niacin, as NAD and NADP, is a coenzyme for over _____ enzymes.
A. 100
B. 200
C. 500
B. 200
NAD functions in catabolic reactions – involving the breakdown of
macronutrients and alcohol to generate energy.
NADP functions in anabolic reactions (the synthesis of macromolecules, fatty acids and steroid hormones). NADP is also involved in the regulation of glutathione, vitamin C and thioredoxin and in the synthesis of folate coenzymes, DNA precursor, deoxyribonucleotide and proline.
**In the body NAD is found largely as NAD and NADP largely in the NADPH form.
Niacin absorption occurs in the _______ and, more readily, in the _________.
A. stomach, small intestine
B. duodenum, jejunum
C. small intestine only
A. stomach, small intestine
**NAD and NADP must be hydrolyzed to release nicotinamide for absorption.
Pellagra is a late stage of severe niacin deficiency. Signs and symptoms of niacin deficiency include:
A. Skin disruption
B. GI upset
C. Nervous system involvement
D. All of the above
D. All of the above
- Skin: Scaly darkly pigmented rash developing symmetrically in areas exposed to sunlight (photosensitive). When it occurs on the neck, it is called Casal’s collar or necklace.
- GI: Glossitis, nausea, vomiting, diarrhea, cheilosis, angular stomatitis. Anorexia (loss of appetite) can set in as deficiency progresses.
-Nervous System: Headache, apathy, fatigue, confusion, depression, disorientation, memory loss, peripheral neuritis, dementia, delirium and even paralysis
of the extremities.
There is increased risk of niacin deficiency with: A. Malabsorption B. Alcoholism C. Certain medications D. Carcinoid syndrome E. A-C F. All of the above
F. All of the above
- Malabsorption: Chronic diarrhea, IBD, Intestinal cancers, Hartnup disease
- Excess alcohol intake
- Certain medications: Isoniazid (for tuberculosis), Mercaptopurine (cancer treatment)
- Carcinoid syndrome: (tumors secrete serotonin and catechol – increasing the utilization of tryptophan for serotonin synthesis).
**Treatment of deficiency is typically with 500 mg niacin daily for several weeks
Over ____ of nicotinic acid daily can lead to vasodilatory effects (mediated in part by histamine release): flushing, redness, burning, itching, tingling, headaches, heartburn, nausea and possibly vomiting.
A. 1g
B. 2g
C. 2.5g
A. 1 g
It is also possible to see hyperuricemia, gout and hyperglycemia.
The RDA of niacin for adults is?
A. 12 mg males, 11mg females
B. 16 mg males, 14mg females
C. 18mg males, 16mg, females
B. 16 mg males, 14mg females
_________, _________, and __________ are required for the synthesis of niacin from tryptophan. Thus deficiencies of any of these can lead to decreased niacin synthesis.
A. Riboflavin, Vitamin B1, and zinc
B. Vitamin B1, Vitamin B6, and iron
C. Riboflavin, Vitamin B6, and iron
C. Riboflavin, Vitamin B6, and iron
FUN FACT: Hydrochloric acid – Niacinamide and nicotinamide have a strong alkalizing effect. Thus supplemental niacin may be best taken apart from HCl
supplementation.
Nicotinamide is the typical form used in supplementation and food fortification.
A. Nicotinic acid
B. Nicotinamide
B. Nicotinamide
It is a component of GTF (Glucose Tolerance Factor) and thus may improve blood glucose
Which method of testing is most beneficial to evaluate niacin status?
A. Serum
B. Urine
C. Stool
B. Urine
Niacin supplementation can be beneficial for which disease states: A. Diabetes B. Cancer C. High Cholesterol D. HIV E. All of the above
E. All of the above
Niacin Drug Interactions:
Lovastatin: coadministration with nicotinic acid can lead to rhabdomyolysis in case reports
Simvastatin: coadministration with nicotinic acid can increase HDL and inhibit progression of coronary artery stenosis, decrease the frequency of MI and stroke (but not if given with antioxidants).
Sulfinpyrazone (for gout): nicotinic
acid may interfere with its therapeutic effects
5Fluoracil: longterm treatment causes pellagra like symptoms for which supplemental vitamin B3 may be needed.
Isoniazid: is a niacin antagonist, so supplement away from each other.
Oral contraceptives with estrogen – decrease dietary need for niacin as they lead to increased niacin synthesis from tryptophan.
Aspirin: coadministration with nicotinic acid can decrease the incidence of skin flushing (but not niacin induced itching or tingling).
Food sources of niacin include:
A. animal proteins, fortified cereals, legumes, coffee, peanuts
B. Leafy greens, legumes, nut/seeds, fortified cereals
A. animal proteins, fortified cereals, legumes, coffee, peanuts
Pantothenic Acid (B5) is absorbed in the: A. stomach B. gallbladder C. jejunum D. large intestine
C. jejunum
-Absorbed in jejunum and excreted mainly in the urine and some in feces
B5 (pantothenic acid) is involved in the synthesis of: A. cholesterol, bile B. fatty acids, phospholipids, C. adrenaline, cortisol D. AA's, steroid hormones E. B & D F. None of the above
E (b and d) Synthesis of Fatty Acids, phospholipids, amino acids, steroid hormones, vitamin A and D
True/False: Animal studies suggest that copper deficiency increases the requirement for pantothenic acid in the diet.
True!
Pantothenic acid deficiency is: A. common B. a global health issue C. rare D. impossible
C. rare- typically only seen with severe malnutrition
The TUL for pantothenic acid is: A. 5mg B. 7mg C. 9mg D. None of the above
D. None of the above
Doses of 15- 20g/d can lead to mild intestinal distress, diarrhea, nausea and heart burn. Pantothenic acid toxicity has not been reported in humans (in doses under 15g/day)
Oral contraceptives with estrogen and progestin \_\_\_\_\_\_ the requirement for pantothenic acid. A. increases B. decreases C. has no change of D. maintains
A. increases
Fun Fact: Pantothenic acid derivative pantethine (which is 2 molecules of pantetheine joined with a disulfide bond ) has cholesterol- lowering effects
Pantethine + HMG CoA reductase inhibitors may have an additive effect on lowering blood lipids. Doses of 300 mg TID (3 times per day) were found to be significantly better than placebo in lowering total cholesterol and triglycerides in diabetics, non-diabetics and diabetics on hemodialysis (which is of great benefit because pantothenic acid has few side effects and is of benefit because of the high risk of drug toxicity in patients with renal failure).
The RDA for adults 19+ of B5 is: A. 2.5mg B. 5mg C. 8mg D. 10mg
B. 5mg
True/False:
Testing: Urinary pantothenic acid excretion is a preferred method for determining pantothenic acid status.
True! Excretion of < 1 mg/d of pantothenic acid is considered poor status of pantothenic acid in the body.
*Blood pantothenic acid: A deficiency is considered likely with blood pantothenic acid levels < 100 mg/dL, BUT: blood concentrations to not correlate well with changes in pantothenic acid intake.
Rich sources of B5 are: A. nuts, seeds, legumes B. beef, chicken, organ meats, whole grains C. Coconut products, full-fat yogurt D. Tomatoes, kiwi, spinach
B. The richest dietary sources are beef, chicken, organ meats, whole grains
Fun Fact: The group most at risk for poor B5 status is: those with PKAN
pantothenate kinase-associated neurodegeneration (PKAN). PKAN is a type of neurodegeneration associated with brain iron accumulation
A large number of PANK2 mutations reduce the activity of pantothenate kinase 2, potentially decreasing the conversion of pantothenic acid to CoA and thus reducing CoA levels
https://ods.od.nih.gov/factsheets/PantothenicAcid-HealthProfessional/
Fun Fact: On the basis of the experiences of prisoners of war in World War II and studies of diets lacking pantothenic acid in conjunction with administration of an antagonist of pantothenic acid metabolism
A deficiency is associated with numbness and burning of the hands and feet, headache, fatigue, irritability, restlessness, disturbed sleep, and gastrointestinal disturbances with anorexia
A typical mixed diet in the United States provides an estimated daily intake of about \_\_\_\_mg , suggesting that most people in the United States consume adequate amounts A. 3mg B. 4mg C. 5mg D. 6mg
D. 6mg
With a typical American diet, the urinary excretion rate for pantothenic acid is about 2.6 mg/day. Excretion of less than \_\_\_\_mg pantothenic acid per day suggests deficiency A. 5mg B. 1mg C. 3 D. None of the above
B. 1mg
Fact: The main function of this water-soluble B vitamin is in the synthesis of coenzyme A (CoA) and acyl carrier protein.
CoA is essential for fatty acid synthesis and degradation
