Vitamin Disorders
ADEK - fat soluble (↓ GI absorption ➔ deficiency)
Vitamin A (retinol)
Vitamin A (retinol) deficiency - Malnutrition (MCC)
↓ night vision, Bitot (gray spots on bulbar conjunctiva), immunosuppression
Vitamin A toxicity
Acute: N/V, blurred vision, vertigo
Chronic: Liver dz, alopecia, arthralgia
Isotretinoin (Vit A derivative) is contraindicated in pregnancy
Vitamin E (tocopherol)
Vitamin E deficiency - Fat malabsorption
Hemolytic anemia and neuro sx (similar sx to B12 but no ↑ MMA)
Vitamin A toxicity
↑ risk of bleeding, ↑ clotting on warfarin
Vitamin K (phytomenadione)
Vitamin K deficiency - Cirrhosis, fat malabsorption, ABX (gut BX synthesize vit K)
↑ bleeding (↑ PT/PTT)
Vitamin D
Inadequate synthesis (not enough UV exposure)
Inadequate diet (vegan, only breast milk in infants)
Impaired metabolism (cirrhosis, CKD, hyperPTH)
Impaired absorption (IBD, bariatric surgery, chronic pancreatitis)
Thiazide diuretics
SSX
Osteoporosis
Hypocalcemia (with high PTH), rickets
DX
25-OH-D (Calcidiol) not 1,25
Insufficiency: 25(OH)D 12-20ng/mL (30-50nmol/L)
Deficiency: 25(OH)D < 12ng/mL (30 nmol/L)
TX
12-20ng/mL: 1,000 IU, qd; < 12ng/mL: 50,000 IU qw x6 wks
You need vitamin D to absorb Ca
Vitamin D ➔ calcium-binding protein (calbindin) ➔ Ca transport across intestine to bloodstream
So... ↓ vitamin D ➔ ↓ Ca absorption ➔ ↑ PTH
Water soluble vitamins
B1 (thiamine)
EToH abuse, malnutrition, bariatric surgery
Dry beriberi: symmetrical peripheral neuropathy, paralysis, confusion
Wet beriberi: cardiomegaly/high output HF
Wernicke encephalopathy (acute and reversible)
Confusion, oculomotor (nystagmus/diplopia) ataxia
Korsakoff syndrome (chronic and irreversible)
Amnesia with confabulation (fabricated memories) and ∆ personalty
B2 (riboflavin)
Corneal vascularization and angular cheilitis
B3 (niacin)
Dermatitis, dementia, diarrhea
B6 (pyridoxine)
From INH
Sideroblastic anemia, seizures/neuropathy
B12 (cobalamin)
Malabsorption - absorbed in stomach (pernicious anemia) and small intestine
Megaloblastic anemia (↑ MMA), hyper-segmented neutrophils
C (ascorbic acid)
Scurvy ➔ ↑ bleeding/anemia, ➔ petechial/perifollicular hemorrhages
Gingivitis ➔ loose teeth