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  1. Copper deficiency is associated with

    A: leukocytosis.
    B: macrocytic anemia.
    C: microcytic hypochromic anemia.
    D: erythrocytosis.
    C: microcytic hypochromic anemia.

    • Patients on long-term parenteral nutrition have developed
    • anemia, leukopenia, neutropenia and skeletal abnormalities. Deficiencies of B12 or
    • folate result in macrocytic anemia (large red blood cells). Deficiencies of
    • iron or copper result in microcytic hypochromic anemia (small red blood cells
    • that are pale in color due to decreased heme pigment). Copper is a
    • metallocofactor for enzymes involved in iron absorption and transport, electron
    • transport, connective tissue cross-linking, and is a component of ceruloplasmin.
  2. A patient receiving PN with a high ileostomy output is likely to require


    A: increased sodium and increased fluid volume.
    B: decreased water and decreased sodium.
    C: increased sodium and decreased protein.
    D: decreased sodium and increased fluid volume.

    • A: increased sodium and increased fluid volume
    • Patients with ileostomy or small bowel fistula output are at risk for water and electrolyte losses. The sodium content of ileostomy output can be as high as 120 meq/liter. Hyponatremia can result when fluid replacement does not contain adequate sodium to correct for ileostomy losses.
  3. Which of the following is a characteristic of kwashiorkor malnutrition?


    A: Splenomegaly
    B: Hypoalbuminemia
    C: Hypoglycemia
    D: Cachexia

    • B: Hypoalbuminemia
    • Kwashiorkor malnutrition is caused by insufficient protein intake during a prolonged period. The clinical features include hypoalbuminemia, edema, ascites, dermatitis, thin brittle hair, hepatomegaly and muscle wasting. In comparison, marasmus is caused by insufficient energy intake, and is characterized by extreme weight loss and cachexia.
  4. Which of the following conditions is most likely to result in malnutrition?


    A: Cancer
    B: Pneumonia
    C: Gastric ulcer
    D: Multiple sclerosis
    A: Cancer
  5. Which of the following is the best indicator of risk for malnutrition?


    A: Serial tricep skinfold remaining at the 20th percentile
    B: Voluntary body mass index change from 30 to 25 over 6 months
    C: Involuntary weight loss of 10% usual body weight over six months
    D: Albumin decrease from 4.0 to 3.5
    • C: Involuntary weight loss of 10% usual body weight over six months
  6. Which of the following is the most appropriate indicator of malnutrition?


    A: Involuntary weight loss of 5% of usual body weight over three months
    B: Involuntary weight loss of 10% of usual body weight over six months
    C: Weight less than 10% of ideal body weight
    D: Weight less than 15% of ideal body weight
    B: Involuntary weight loss of 10% of usual body weight over six months

    Involuntary weight loss of greater than or equal to 5% of usual body weight in one month or 10% in 6 months are indicative of malnutrition. Body weight below ideal does not necessarily indicate malnutrition. Weight loss of 20% of ideal body weight, especially with increased nutritional requirements or if the loss is associated with chronic disease is an indicator of malnutrition.
  7. Which of the following is most characteristic of metabolism in both stress- and starvation-related malnutrition?


    A: Ketosis
    B: Hypoglycemia
    C: Lipolysis
    D: Hypermetabolism
    C: Lipolysis
  8. Which of the following methods of nutrition assessment evaluate subcutaneous fat and muscle wasting at multiple body sites to determine nutritional status?


    A: Nutritional risk index (NRI)
    B: Prognostic nutrition index (PNI)
    C: Subjective Global Assessment (SGA)
    D: Prognostic inflammatory and nutritional index (PINI)
    C: Subjective Global Assessment (SGA)
  9. Subjective global assesment info
    The SGA evaluates nutritional status using five historical and four physical examination parameters. The historical information includes: weight history, dietary intake, gastrointestinal symptoms, functional status, and metabolic demand. The physical examination parameters include subjective measures of subcutaneous fat, muscle wasting, edema, and ascites at more than one body site. The historical and physical examination data are subjectively weighted to classify the patient as well nourished, moderately malnourished, or severely malnourished. The SGA has been found to be a good predictor of complications in patients undergoing gastrointestinal surgery, liver transplantation, and dialysis.
  10. Nutrition risk index, prognostic nutrition index and prognostic inflammatory and nutritional index info
    The PNI, NRI, and PINI are prognostic indices that include objective measures of nutrition status. The formula for PNI includes a triceps skin fold thickness measurement, and serum albumin and transferrin levels, and delayed hypersensitivity skin test reactivity. The formula for PINI includes markers of the inflammatory response (alpha A acid glycoprotein and C-reactive protein) in addition to albumin and prealbumin. The formula for NRI uses serum albumin and the ratio of current weight to usual weight.
  11. The Subjective Global Assessment used to evaluate the nutritional status of patients includes


    A: dietary intake, delayed hypersensitivity skin testing, and weight history.
    B: weight history, dietary intake, and gastrointestinal symptoms.
    C: laboratory indices, weight history, and gastrointestinal symptoms.
    D: arm anthropometry, dietary intake, and laboratory indices.
    B: weight history, dietary intake, and gastrointestinal symptoms.
  12. Which of the following has been reported to be a significant independent predictor of morbidity and mortality in critically ill patients?


    A: Albumin
    B: Prealbumin
    C: Transferrin
    D: Retinol-binding protein
    A: Albumin

    albumin was a significant independent predictor of morbidity and mortality. ICU and hospital length of stay, ventilator days, risk of infection and mortality were significantly greater for patients with a serum albumin <1.6 g/dL.
  13. A previously well-nourished patient with persistent fever is admitted to the hospital. His laboratory tests reveal: albumin, 2.1 g/dL; C-reactive protein, 21 mg/L; serum calcium of 7.2 mg/dL. Which of the following is the most likely reason of the hypoalbuminemia?


    A: Caloric intake is below the recommendations
    B: Protein intake is below the recommendations
    C: Hypocalcemia
    D: Inflammatory response

    • D: Inflammatory response
    • Albumin may decrease during inflammation and hypervolemia. Even though it is a good predictive indicator of clinical outcome, it does not always reflect nutritional status. C-reactive protein above 10mg/L reflects an inflammatory status, which may be the reason of the referred hypoalbuminemia. Positive acute phase protein concentrations such as C-reactive protein increase during inflammation, whereas negative acute phase protein concentrations such as albumin and pre-albumin decrease during inflammation. Although there is a causal relationship between hypoalbuminemia and hypocalcemia, a low serum calcium does not cause a low serum albumin.
  14. Which of the following compromises the reliability of urinary urea nitrogen to calculate nitrogen balance?


    A: protein intake <0.5 g/kg/day
    B: creatinine clearance <50 mL/min
    C: diuresis >2.5 L
    D: fecal nitrogen >1g
    B: creatinine clearance <50 mL/min
  15. Which of the following has been shown to reduce plasma homocysteine concentrations?


    A: Folic acid
    B: Vitamin E
    C: L-carnitine
    D: Ascorbic acid
    A: Folic acid
  16. Which of the following is the most appropriate fluid requirement for a healthy adult?


    A: 15-20 ml fluid/kg/day
    B: 20-25 ml fluid/kg/day
    C: 30-35 ml fluid/kg/day
    D: 40-45 ml fluid/kg/day
    C: 30-35 ml fluid/kg/day
  17. Which of the following enzymes initiates the digestive process of carbohydrates in the mouth?


    A: Lipase
    B: Lactase
    C: Maltase
    D: Amylase

    D: Amylase
  18. Iron is primarily absorbed in the


    A: distal ileum.
    B: distal jejunum.
    C: proximal ileum.
    D: proximal jejunum
    D: proximal jejunum.
  19. Iron is absorbed primarily in the proximal jejunum in the ferrous state rather than the ferric state. The ferric form of iron is insoluble in aqueous solutions and, therefore, not absorbed. Gastric acid is very important in maintaining dietary iron in the ferrous state.
  20. Which of the following amino acids is most crucial in small intestinal structure and function?


    A: Alanine
    B: Leucine
    C: Aspartate
    D: Glutamine
    D: Glutamine
  21. In persons with phenylketonuria, tyrosine becomes an essential amino acid due to


    A: an increase in the tyrosine hydroxylase enzyme.
    B: a deficiency in the phenylalanine hydroxylase enzyme.
    C: an increase in the phenylalanine hydroxylase enzyme.
    D: a decrease in the tyrosine hydroxylase enzyme.
    B: a deficiency in the phenylalanine hydroxylase enzyme.
  22. Which of the following is an aromatic amino acid?


    A: Valine
    B: Leucine
    C: Tyrosine
    D: Isoleucine
    C: Tyrosine
  23. Which of the following are examples of conditionally indispensable amino acids?


    A: Leucine and Isoleucine
    B: Phenylalanine and Valine
    C: Glutamine and Arginine
    D: Histidine and Tryptophan

    C: Glutamine and Arginine

    Conditionally indispensable amino acids are synthesized from other amino acids under normal conditions but require a dietary source in order to meet increased needs caused by metabolic stress. For example, Arginine becomes conditionally indispensable for wound healing. Conditionally indispensable amino acids include: Arginine, Cysteine, Glutamine, Glycine, Proline and Tyrosine.
  24. An NPO post-operative patient has been on 2-in-1 parenteral nutrition (PN) for three weeks. He develops a diffuse scaly dermatitis, hair loss, anemia and thrombocytopenia. Which of the following is the probable cause?

    A: He has not been receiving IV fat emulsion (IVFE) for three weeks.
    B: He has been receiving trace elements C times per week due to a national shortage.
    C: He is receiving B0 kcal/kg per day from PN because of hyperglycemia.
    D: He has PN related cholestasis and is experiencing fat malabsorption.
    • A: He has not been receiving IV fat emulsion (IVFE) for three weeks.
    • Provision of fat free PN for three weeks has resulted in essential fatty acid deficiency. Signs of essential fatty acid deficiency include scaly dermatitis, alopecia, thrombocytopenia, anemia and impaired wound healing. Provision of 2-4% of total calories as fat should be sufficient to prevent essential fatty acid deficiency.
  25. Which of the following IV fluids most closely resemble jejunal and ileal electrolyte content?

    A: Lactated Ringer
    B:
    0.9% Sodium chloride (normal saline)
    C:
    0.45% Sodium chloride (1/2 normal saline)
    D:
    D5 0.45% Sodium chloride
    A: Lactated Ringer

    • The electrolyte content of gastrointestinal secretions changes according to their location along the GI tract. The composition of jejunal and ileal fluids is listed below. Jejunum: Sodium = 95-120 mEq/L; Potassium = 5-15 mEq/L; Chloride = 80-130 mEq/L; Bicarbonate = 10-20 mEq/L. Ileum: Sodium = 110-130 mEq/L; Potassium = 10-20 mEq/L; Chloride = 90-110 mEq/L; Bicarbonate = 20-30 mEq/L. Lactated Ringer most closely resembles these values. IV electrolyte content is as follows: Lactated Ringer: Glucose = 0; Sodium = 130 mEq/L; Chloride = 109 mEq/L; Potassium = 4 mEq/L; Lactate = 28 mEq/L; Calcium = 2.7 mEq/L. 0.9% Sodium Chloride (NS) contains only: Sodium - 154 mEq/L and Chloride 154 mEq/L. 0.45% Sodium Chloride (1/2 NS) contains only: Sodium = 77 mEq/L and Chloride = 77 mEq/L. D5 0.45% Sodium Chloride contains: Glucose = 50 grams/L; Sodium = 77 mEq/L; Chloride = 77 mEq/L.
  26. Which of the following clinical situations would best describe a critically ill patient with syndrome of inappropriate antidiuretic hormone (SIADH)?

    A: Appears euvolemic but is total body water overloaded because there is inappropriate concentration of the urine
    B:
    Appears hypervolemic and is total body water overloaded because there is inappropriate dilution of the urine
    C:
    Appears hypovolemic but is total body water overloaded because there is inappropriate fluid resorption in the kidneys
    D:
    Appears euvolemic but is total body water overloaded because there is inadequate production and release of anti-diruetic hormone from the adrenal glands
    A: Appears euvolemic but is total body water overloaded because there is inappropriate concentration of the urine

    Hyponatremia associated with SIADH is common in the critically ill patient. It is seen frequently in patients with central nervous system disease, malignancy, lung disease and can also be a side effect of medications such as diuretics, antidepressants, and analgesics. The role of antidiuretic hormone is to control water loss via the kidneys depending on individual hydration status. When excessive antidiuretic hormone is produced, water is conserved rather than excreted and the urine becomes concentrated. Spot urine sodium levels and urine osmolality will both be elevated.
  27. In a patient with nonhealing wounds suspected of having a vitamin A deficiency, supplementation of vitamin A (15,000 IU/day) should usually be given for a MAXIMUM of
    A: 2 days.
    B: 10 days.
    C:
    45 days.
    D:
    60 days.
    • B: 10 days.
  28. A patient with alcoholism is admitted with small bowel obstruction and is started on PN providing 400 grams of dextrose. If, after 3 days, the patient develops Wernicke's encephalopathy it is most likely due to a deficiency of

    A: pyridoxine.
    B:
    thiamine.
    C:
    folic acid.
    D:
    vitamin C
    B: thiamine.
  29. Lactic acidosis can be a result of which vitamin deficiency?
    A: Folic acid
    B: Vitamin E
    C: Thiamine
    D: Vitamin C
    C: Thiamine

    Thiamine is necessary for the metabolism of glucose, specifically, the conversion of pyruvate to acetyl CoA. In the absence of thiamine, pyruvate is converted to lactic acid. This, sometimes fatal, adverse event has occurred within a week of thiamine abstinence. The relatively high glucose loads of parenteral nutrition exacerbate the risk. Despite adequate supplies of adult parenteral multivitamin preparations since 1999, suboptimal dosing practices have persisted.
  30. In addition to aggressive refeeding, which of the following places a patient at high risk for hypophosphatemia?

    A: Diabetic ketoacidosis, chronic alcoholism
    B: Parkinson disease, tumor lysis syndrome
    C: Pancreatitis, Fanconi syndrome
    D: Acute renal failure, SIADH
    A: Diabetic ketoacidosis, chronic alcoholism
  31. The risk of metastatic calcification of calcium phosphate in soft tissues increases when the product of phosphorus and calcium in the serum (serum phosphorus x serum total calcium) exceeds
    A: 25.
    B: 35.
    C: 45.
    D: 55.
    D: 55.
  32. Zinc deficiency caused by malnutrition is most likely to result in

    A: diarrhea.
    B: carotenemia.
    C: coagulopathy disorder.
    D: increased absorption of nutrients.
    A: diarrhea.
  33. Copper toxicity is associated with

    A: liver disease.
    B: kidney disease requiring hemodialysis.
    C: aggressive zinc supplementation.
    D: lung disease.
    A: liver disease.

    • Since about 80% of copper is excreted in the bile, patients who have liver disease should be monitored and supplementation reduced or eliminated. Hemodialysis increases copper losses. Zinc supplementation can impair copper absorption.
  34. Hepatic encephalopathy is most likely to be improved by which of the following trace elements?

    A: Selenium
    B: Copper
    C: Zinc
    D: Chromium
    C: Zinc
  35. Which of the following best describes the utility of aluminum in parenteral solutions?

    A: Potentiates the action of insulin
    B: Has no known biologic function
    C: Decreases the incidence of bone fractures
    D: Is necessary for normal erythropoiesis
    • B: Has no known biologic function
    • Aluminum has not been shown to have any biologic function but is present as a contaminant in many PN components. Toxicity occurs upon accumulation and can result in abnormalities of hematopoietic, bone, and neurologic functions. Complications of aluminum intake are best avoided by minimizing the use of aluminum-containing agents such as antacids, sucralfate, etc. Aluminum toxicity is treated with deferoxamine, an agent that chelates aluminum.
  36. Which of the following can result in an invalid indirect calorimetry measurement?

    A: Enterocutaneous Fistula
    B: Chest tube leak
    C: Hemodynamic stability
    D: Inspired oxygen (FiOB) less than 60%
    • B: Chest tube leak
    • Clinical factors can affect the validity of indirect calorimetry measurements in critical illness. For instance, if the patient requires inspired oxygen (FiOB) > 60%, the indirect calorimetry study should not be performed since the results may be inaccurate. The presence of an air leak can produce invalid results, as possible with a chest tube or bronchopleural fistula and within an endotracheal tube cuff. Furthermore, hemodialysis can alter measurements because of the potential loss of CO2 through the dialysis coil.
  37. In assessing the caloric goal for patients receiving nutrition support, the measured resting energy expenditure determined from indirect calorimetry should be

    A: reduced by 10% if respiratory quotient exceeds 1.0.
    B: increased by a stress factor of 1.2-1.5 for sepsis or trauma.
    C: adjusted by a thermogenesis factor for enterally fed patients.
    D: used as the caloric target without addition of stress or activity factors.
    • D: used as the caloric target without addition of stress or activity factors.
    • Resting energy expenditure (REE) measured under steady state conditions closely approximates true 24-hour energy expenditure. The addition of a stress or activity factor may not be necessary and could result in overfeeding. If a patient is measured while fasting or if feedings are intermittently provided, it is reasonable to allow an additional 5% factor to account for thermogenesis.
  38. A respiratory quotient (RQ) of .95 most likely suggests

    A: primarily fat oxidation.
    B: mixed substrate utilization.
    C: underfeeding.
    D: overfeeding.
    B: mixed substrate utilization.
  39. Which of the following predictive equations has demonstrated the greatest accuracy in estimating actual resting metabolic rate in obese and nonobese adults?

    A: Owen using adjusted body weight
    B: Harris-Benedict using actual body weight
    C: Harris-Benedict using adjusted body weight
    D: Mifflin-St. Jeor using actual body weight
    • D: Mifflin-St. Jeor using actual body weight
    • The Mifflin-St. Jeor equations have demonstrated the greatest accuracy with obese and non-obese people when compared to the Owen equations and Harris-Benedict equations using either adjusted or actual body weight. The Mifflin-St. Jeor equations are as follows: For males: Actual body weight in kg x 9.99 plus Height in cm x 6.25 minus age in years x 4.92 plus 5. For females: Actual body weight in kg x 9.99 plus Height in cm x 6.25 minus age in years x 4.92 minus 161.
  40. Cheilosis is a physical symptom associated with a deficiency of

    A: vitamin D.
    B: folic acid.
    C: riboflavin.
    D: vitamin C.
    • C: riboflavin.
    • Cheilosis, cracking of the corners of the mouth, is observed with a deficiency of riboflavin, niacin, iron, and pyridoxine.
  41. Malnutrition is most common in which of the following forms of inflammatory bowel disease?

    A: Crohn's disease
    B: Ulcerative colitis
    C: Microscopic colitis
    D: Collagenous colitis
    • A: Crohn's disease
    • Since Crohn's disease usually involves the small intestine, malnutrition and micronutrient deficiencies are much more common than with ulcerative, microscopic, or collagenous colitis. Depending on severity of disease, weight loss has been reported in 65% to 78% of those with Crohn's disease. Possible mechanisms for malnutrition in Crohn's disease include malabsorption from diseased small bowel mucosa, increased nutrient requirements from active inflammation, and reduced oral food intake due to abdominal discomfort and diarrhea.
  42. An end stage liver disease patient with refractory ascites is awaiting liver transplantation and is intolerant to tube feeding. His serum sodium is 128 mEq/L. Which of the following would be most appropriate to recommend?

    A: No parenteral nutrition
    B: Restrict fluid, restrict sodium , provide 0.5 g/kg per day protein
    C: restrict fluid, restrict sodium, provide A.5 g/kg per day protein
    D: Restrict fluid, supplement sodium, provide A.0 g/kg per day protein
    C: restrict fluid, restrict sodium, provide 1.5 g/kg per day protein
  43. Appropriate treatment for ascites includes fluid and sodium restriction. Current literature supports the use of protein 0.8 to 1.2 g/kg/day for maintenance and 1.3 – 2.0 g/kg/day for repletion. While optimum nutrition support may not be possible, use of maximally concentrated solutions provides the best opportunity to avoid further salt and fluid overload while providing necessary substrate for anabolism.
  44. Arginine supplementation should be used most cautiously in which of the following patients?

    A: Trauma patients
    B: Surgical patients
    C: Septic shock patients
    D: Immunocompromised patients
    • C: Septic shock patients
    • Arginine, which increases the production of nitric oxide, has been shown to have positive effects on recovery from trauma and surgery through its effect on blood flow, immune function, wound healing, and organ failure. In conditions of pronounced vasodilation, as in septic shock, the production of nitric oxide would be expected to exacerbate hemodynamic instability. Increased mortality and morbidity in this population has been demonstrated in some studies.
  45. What is the approximate normal length of small intestine in adults?
    A: 100 cm
    B: 150 cm
    C: 200 cm
    D: 600 cm
    • D: 600 cm
    • The normal small intestine is approximately 600 cm in length. The colon is approximately 150 cm. Patients with less than 150-200 cm of small bowel without a colon may have significant fluid and nutrient losses, i.e. short bowel syndrome.
  46. What is the primary fuel of the colonocytes?

    A: Medium chain fatty acids
    B: Glucose
    C: Glutamine
    D: Short chain fatty acids
    • D: Short chain fatty acids
    • Short chain fatty acids are the primary fuel product for colonic cells. The short chain fatty acids include acetate, propionate, and butyrate. The colon can convert (by fermentation) complex carbohydrate to short chain fatty acids. The short chain fatty acids stimulate water and sodium absorption in the colon and provide a source of calories as well.
  47. Dietary fat is predominately absorbed in what part of the intestine?

    A: Ileum and colon
    B: Stomach and duodenum
    C: Distal jejunum and ileum
    D: Duodenum and proximal jejunum
    • D: Duodenum and proximal jejunum
    • Absorption of fat in the normal person occurs predominantly in the duodenum and proximal jejunum. Conjugated bile acids released into the proximal intestine forms polymolecular aggregates called mixed micelles, which aid in the solubilization and absorption of dietary fat.
  48. Gastrectomy patients are at risk for a deficiency of which vitamin?
    A: B12
    B: Folic Acid
    C: Thiamine
    D: B6
    A: B12
  49. Which of the following anatomic structures is LEAST important to the function of a massively resected gastrointestinal tract?
    A: Colon
    B: Ileum
    C: Jejunum
    D: Ileocecal valve
    • A: Colon
    • B: Ileum
    • C: Jejunum
    • D: Ileocecal valve
    • The ileum has specific absorption functions that cannot be performed in any other area of the GI tract. The ileocecal valve and colon play an important role in transit time and electrolyte balance. The jejunum cannot adapt to perform the functions of a resected ileum or colon, whereas the illeum or colon can assume function of a resected jejunum over time.
  50. Which of the following is associated with adaptation to starvation?

    A: Hyperthermia
    B: Reduced muscle mass
    C: Lipogenesis
    D: Increased cardiac capacity
    • B: Reduced muscle mass
    • During starvation, successful adaptation reduces energy and protein requirements as long as the ratio of energy to protein is not too low. The physiologic costs of adaptation are lowered metabolic rate, reduced muscle mass, muscular weakness, functional disability, mild hypothermia, and reduced cardiac and respiratory capacity. Adaptation to starvation helps restore homeostasis and helps the body maintain key physiologic functions.
  51. What is the fluid requirement for patients during critical illness and sepsis?
    A: 15-25 mL/kg/day
    B: 30-40 mL/kg/day
    C: 45-55 mL/kg/day
    D: 60-70 mL/kg/day
    B: 30-40 mL/kg/day

    • Water is imperative for digestion, transport, and metabolism of nutrients as well as elimination of waste. Fluid volume of 30-40 mL/kg/day is needed to meet the fluid demand seen in critical illness, as well as to maintain adequate urine output.
  52. Valproic acid (Depakene) has been shown to induce a deficiency in which of the following nutrients?
    A: Copper
    B: Carnitine
    C: Fatty acids
    D: Essential amino acids
    • B: Carnitine
    • Valproic acid (Depakene), an antiepileptic drug, has been shown to induce carnitine deficiency. The mechanism of this effect is not fully explained. Impaired renal handling may be involved. Carnitine is involved in the metabolism of fatty acids. The idiopathic encephalopathy associated with carnitine deficiency is reversed with L-carnitine supplementation and restoration of carnitine serum levels. Fatalities have been reported in untreated carnitine deficiency.
  53. Methotrexate acts by interfering with the normal intracellular metabolism of which of the following nutrients?
    A: Thiamine
    B: Folate
    C: Carnitine
    D: Vitamin D
    B: Folate

    • The chemotherapeutic drug methotrexate is an antifolate compound that first entered clinical trials in the A950s and is one of the best-studied agents targeting the folate pathway. Folate analogues, such as methotrexate, are structurally similar to folate but are able to bind with and inhibit the action of various enzymes. Methotrexate acts primarily as an inhibitor of dihydrofolate reductase, resulting in an accumulation of dihydrofolate and a depletion of other folate pools.
  54. Question: 50
    What vitamin absorption is most likely to be impaired with the use of proton pump inhibitor therapy?

    A: Vitamin A
    B: Vitamin C
    C: Vitamin B6
    D: Vitamin B12
    • D: Vitamin B12
    • Protein-bound dietary vitamin B12 requires gastric acidity for optimal release of free vitamin B12 from food; it is this free vitamin B12 that binds to R protein in the stomach and eventually to intrinsic factor in the small intestine for absorption. Proton pump inhibitors decrease gastric acidity and may thus interfere with the absorption of protein-bound dietary vitamin B12. Absorption of crystalline vitamin B12, the form utilized in vitamin supplements and fortified foods, is not affected by gastric acid.

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