01/13/15 - Nutrition

Question 1

A patient on a long course of broad-spectrum antibiotics develops oozing from his IV sites, and is found to have prolonged PT, PTT, but a normal platelet count. Which of the following coagulation factors would most likely be deficient first in this patient?

A. Factor II
B. Factor VII
C. Factor V
D. Factor XII

Answer 1

B. Factor VII

The history of broad-spectrum antibiotics implies that the bleeding is due to loss of vitamin K, which is required for factors II, VII, IX, and X. VII has a shorter half-life than II.

Question 2

An 80yo man presents with macrocytic anemia and elevated methylmalonate levels. Hypersegmented neutrophils are seen on his blood smear. If his vitamin deficiency is untreated, what neurological symptoms will develop?

A. Encephalopathy/confabulation
B. Dysarthria & diplopia
C. Paresthesias & ataxia
D. None; this defiency doesn’t cause neurologic symptoms.

Answer 2

C. Paresthesias & ataxia

Macrocytic anemia points to folate or B12 deficiency, of which only B12 deficiency causes accumulation of methylmalonate. Confabulation is seen in Korsakoff psychosis (thiamine), while dysarthria/diplopia are rarely seen in vitamin deficiencies.

Question 3

A 25yo presents with bleeding gums and poorly healing wounds on his legs. His hemoglobin is low, but platelet and coagulation tests are normal. What is causing his symptoms?

A. Decreased platelets
B. Fight club
C. Defect in hydroxylation of collagen residues
D. Mutation of dystrophin
E. Mutation of spectrin

Answer 3

C. Defect in hydroxylation of collagen residues

Bleeding gums is a classic sign in scurvy, which would cause weakening of vessels. Mutations in dystrophin cause muscular dystrophies (patient would present with weakness), while spectrin mutations cause spherocytosis (which does not cause bleeding)

Question 4

A 6mo baby is fed largely on rice milk. She develops a very round belly and pitting edema in her extremities. What nutrient deficiency is to blame?

A. Calorie
B. Carbohydrate
C. Fat
D. Protein

Answer 4

D. Protein

This is kwashiorkor, in which protein deficiency produces hypoalbuminemia, causing edema/ascites. Caloric deficit causes Merasmus, of which sufferers appear gaunt rather than bloated.

Question 5

A 15mo baby presents with broad-based waddling gait. She has low calcium, low-normal phosphate, and elevated serum alkaline phosphatase. What process is most likely deficient?

A. Demineralization of osteoid matrix
B. Hydroxylation of proline and lysine in collagen
C. Intestinal absorption of calcium and phosphate
D. Renal absorption of calcium and phosphate

Answer 5

C. Intestinal absorption of calcium and phosphate

The child has Rickets; in which vitamin D is deficient, leading to impaired absorption of calcium (abnormal mineralization >> gait). Renal absorption of calcium and phosphate is not dependent on vitamin D.

Question 6

A 39yo homeless woman is diagnosed with TB and prescribed isoniazid. Several months later, the patient has itchy skin, a beefy tongue, diarrhea, and forgetfulness. What vitamin supplement does the patient need?

A. Vitamin C
B. Folate
C. Niacin
D. Thiamine
E. Vitamin D

Answer 6

C. Niacin

• This is pellagra; isoniazid impairs endogenous synthesis from tryptophan. Note the “3 Ds”: Diarrhea, dementia, and dermatitis.*
• Note: According to other board resources, pyridoxine depletion is more significant than niacin depletion. Still, Stoner says…*

Question 7

Dr. Stoner goes on a wine-only diet. She then presents to the ED confused, with blurry vision and memory loss. What MRI finding will she have?

A. Atrophy of the caudate nucleus
B. Depigmentation of the substantia nigra; pars compacta
C. Neurofibrillary tangles & enlarged ventricles
D. Symmetrics legions in the paraventricular thalamus, hypothalamus, mammillary bodies, and peridaqueductal grey.

Answer 7

D. Symmetrics legions in the paraventricular thalamus, hypothalamus, mammillary bodies, and peridaqueductal grey.

Wernicke-Korsakoff psychosis characteristically affects these areas. A-C describe Huntington’s disease, Parkinson’s disease, and Alzheimer’s diseases respectively.

Question 8

Thiamine deficiency often presents with polyneuropathy of the distal extremities causing paresthesias and motor dysfunction. How else might it present?

A. Chronic infection
B. Seizures & jaundice
C. Diarrhea, dermatitis, & dementia
D. Congestive heart failure w/ edema

Answer 8

D. Congestive heart failure w/ edema

This is “wet beriberi”, caused by B1 deficiency. Infections may be seen in some mineral deficiencies, seizures/jaundice is seen in folate deficiency, and the “3 Ds” note pellagra (niacin deficiency)

Question 9

When moved to very dim lighting, a student trips over some objects after failing to see them. If this were due to a vitamin deficiency, how would that vitamin have been absorbed?

A. Apoferritin-mediated transport
B. Intrinsic factor mediated transport
C. Micelle mediated transport
D. Sodium dependent cotransport
E. Vitamin D dependent transport

Answer 9

C. Micelle mediated transport

The vitamin in question is vitamin A; this is a fat soluble vitamin and as such would require micelles for absorption. Apoferritin facilitates iron absorption, intrinsic factor facilitates B12 absorption, Vitamin D facilitates calcium absorption, and sodium cotransport facilitates absorption of most of the water-soluble vitamins.

Question 10

An older patient is considering pregnancy but is found a macrocytic anemia due to folate deficiency, which could cause neural tube defects. What is the function of folic acid?

A. Hydroxylates prolyl- and lysyl- residues
B. Increases intestinal calcium and phosphate absorption
C. Comprises the visual pigments
D. Transfers 1-carbon intermediates

Answer 10

D. Transfers 1-carbon intermediates

Folate (with the help of B12) handles 1-carbon transfer reactions. Answers A-C describe Vitamins C, D, and A respectively.