Vitamins

Question 1

Explain signs of Vitamin B1 - Thiamine deficiency

Answer 1

Muscle cramps, paresthesias, irritability
Wet beriberi => neuropathy + heart failure (peripheral vasodilation, biventricular failure, edema)
Dry beriberi => motor and sensory neuropathy
Wernicke-Korsakoff syndrome => ophthalmoplegia, turncal ataxia, confusion

Question 2

Explain signs of Vitamin B2 - Riboflavin deficiency

Answer 2

Glossitis, cheilosis, corneal vascularization
Angular stomatitis, seborrheic dermatitis, weakness
Hemolytic anemia

Question 3

Explain signs of Vitamin B3 - Niacin deficiency

Answer 3

Pellagra => diarrhea, dermatitis, dementia

Hyperpigmented, brittle, cracked, and scaly skin

Question 4

Explain signs of Vitamin B6 - Pyridoxine deficiency

Answer 4

Convulsions, hyperirritability

May occur after too much use of oral contraceptives, isoniazid, cycloserine, penicillamine

Question 5

Explain signs of Vitamin B6 - Pyridoxine excess

Answer 5

Sensory neuropathy that persists after correction

Question 6

Explain signs of Vitamin B12 - Cobalamin deficiency

Answer 6

Pernicious anemia = autoimmune attack on gastric parietal cells => no production of IF
Neuropathy from defective myelin formation => subacute degeneration of posterior and lateral spinal columns => symmetrical paresthesias and ataxia, loss of proprioception and vibration => severe: spasticity, clonus, paraplegia, fecal/urinary incontinence
Megaloblastic anemia and hypersegmented neutrophils

Question 7

Explain signs of folate deficiency

Answer 7

Megaloblastic anemia with mucosal changes, no neurological sequelae
Neural tube defects in pregnant women

Question 8

Explain signs of Vitamin C deficiency

Answer 8

Scurvy => swollen gums, bruising, anemia, poor wound healing

Question 9

Explain signs of Vitamin A - Retinoid deficiency

Answer 9

Vision problems, impaired immune responses
Headaches, skin changes, sore throat, alopecia
Loss of green light sensitivity, poor adaptation to dim light, night blindness
Xerophthalmia (squamous epithelial thickening), Bitot spots (squamous metaplasia), and keratomalacia (softening of cornea)
Frequent respiratory infections from metaplasia of respiratory epithelia

Question 10

Explain signs of Vitamin A excess

Answer 10

Acute = nausea, vertigo, blurry vision
Chronic = ataxia, alopecia, hyperlipidemia, hepatotoxicity
Teratogenic = fetal loss

Question 11

Explain signs of Vitamin D deficiency

Answer 11

Children => rickets = hypocalcemia, bowing of lower extremities, poor dentition
Adults => osteomalacia = same as rickets

Question 12

Explain treatment for Type I vitamin D - resistant rickets

Answer 12

Genetic mutation of 1a-hydroxylase => cannot metabolize vitamin D in kidney
Treat with 1,25-dihydroxyvitamin D
If that doesn’t work, then patient has Type II

Question 13

Explain X-linked rickets

Answer 13

Renal phosphate wasting => 1,25-OHD levels are elevated

Question 14

Explain signs of Vitamin D excess

Answer 14

Hypercalcemia => kidney stones, dementia, constipation, abdominal pain, depression
Sarcoidosis, lymphoma => lead to excess vitamin D because pulmonary macrophages/lymphomas can produce calcitriol

Question 15

Explain Vitamin E deficiency

Answer 15

Hemolytic anemia, peripheral neuropathy, ophthalmoplegia

Question 16

Explain Vitamin E excess

Answer 16

Interfere with vitamin K metabolism => bleeding

Question 17

Explain Vitamin K deficiency

Answer 17

Decreased synthesis of clotting factors II, VII, IX, and X => elevated PT
Decreased synthesis of Proteins C and S

Question 18

Explain pathophysiology of DKA

Answer 18

High glucose but insufficient insulin levels => glucagon and other stress hormones begin to rise => liver produces exceptional amount of ketone bodies (metabolic acidosis) => H/K transition => hyperkalemia

Question 19

Explain presentation of DKA

Answer 19

Increased respiratory rate and tidal volumes = Kussmaul respirations
Lethargy/fatigue, abdominal pain, shortness of breath

Hyperglycemia = polyuria, polydipsia, weight loss
Hyperglycemic hyperosmotic nonketotic coma (in type II DM’s)

Question 20

Explain treatment of DKA

Answer 20

Isotonic IV saline
Insulin
K+ replacement (high blood K, but low total body K)