Vitamin deficiencies

Question 1

Vitamin A deficiency - overview (3)

Answer 1

1. Causes (‘3’) = fat malabsorption states, e.g. CF, deficient Indigenous diet
2. Presentation (5) = increased morbidity and mortality from infections, follicular hyperkeratosis, xerophthalmia (dryness of conjunctiva and cornea of eye), night blindness; plasma retinol

Question 2

Vitamin D deficiency - overview (3)

Answer 2

1. Causes (3) = dietary deficiency, low UV light, hepatic/renal failure
2. Presentation (5) = rickets (limb X-rays, distal bony cupping and fraying), reduced serum calcium, reduced serum phosphate (due to decreased gastric absorption and increased urinary loss, increased ALP, plasma 25-hydroxy cholecalciferol (major circulating form of vitamin D)

Question 3

Vitamin E deficiency - overview (3)

Answer 3

1. Causes (2) = prematurity, fat malabsorption

2. Presentation (2) = haemolytic anaemia, serum vitamin E level

Question 4

Vitamin K deficiency - overview (3)

Answer 4

1. Causes (3) = congenital, fat malabsorption states, small bowel bacterial overgrowth
2. Presentation (1) = bleeding (including haemorrhagic disease of the newborn)
3. Mx (1) = IV 1mg vitamin K1

Question 5

Vitamin B1 deficiency - overview (3)

Answer 5

1. Causes (1) = dietary deficiency (esp. when polished rice staple diet)
2. Presentation (3) = beri-beri (muscle weakness, edema, heart failure), Wernicke’s encephalopathy, red cell thiamine pyrophosphate

Question 6

Vitamin B12 deficiency - overview (3)

Answer 6

1. Causes (3) = vegan diets, distal small bowel disease (e.g. Crohn’s disease), pernicious anaemia
2. Presentation (3+2=5) = macrocytic megaloblastic anaemia, peripheral neuropathy, motor weakness. Vitamin B12 level

Question 7

Vitamin C deficiency - overview (3)

Answer 7

1. Causes (1) = lack of fresh fruit and vegetables
2. Presentation (5) - scurvy = petechiae/ecchymoses, bleeding gums, painful sub-periosteal bleeding of legs, motor weakness. Plasma vitamin C level

Question 8

Folic acid deficiency - overview (3)

Answer 8

1. Causes = small bowel disease, malignancy, drugs (anticonvulsants, cytotoxic drugs)
2. Presentation (5) = macrocytic megaloblastic anaemia, irritability, failure to thrive, thrombocytopenia. Red cell folate

Question 9

Iron deficiency - overview (3)

Answer 9

1. Causes (3) = low dietary intake, chronic blood loss (e.g. intestinal parasites or malaria), prematurity
2. Presentation (4+’1’) = microcytic hypochromic anaemia, developmental delay, angular stomatitis, koilonychia. Serum ferritin 90mmol/L
3. Mx (1) = oral 4-6mg/kg/d iron

Question 10

Zinc deficiency - overview (3)

Answer 10

1. Causes (5) = prematurity, dietary insufficiency, intestinal disease, chronic diarrhoea, acrodermatitis enteropathica (inborn error of zinc absorption)
2. Presentation (5 + 1) = peri-orifacial and anal dermatitis, diarrhoea, alopecia, FTT, neurological dysfunction. Serum zinc 10y 10mg/d

Question 11

Iron deficiency - overview (3)

Answer 11

1. Causes (1) = dietary deficiency (endemic in some regions)
2. Presentation (3) = hypothyroidism, delayed development. Low urine iodine:creatinine ratio
3. Mx (1) = oral 100-300mcg/d iodine and oral levothyroxine replacement