CHAPTER 9 Vitamins and Minerals^141
Dose for treatment of deficiency 100,000–500,000 IU daily ×3 d; then 50,000 IU ×14 day
Maintenance 10,000–20,000 IU q.d. ×60 day
Pregnancy category A; PB: UK; t^1 / 2 : weeks–months*
Deficiency conditions Treats vitamin A deficiency, prevents night blindness,
treats skin disorders, promotes bone development
Side effects Headache, fatigue, drowsiness, irritability, anorexia,
vomiting, diarrhea, dry skin, visual changes
Adverse reactions Evident only with toxicity; leucopenia, aplastic anemia,
papilledema, increased intracranial pressure,
hypervitaminosis A (loss of hair and peeling skin).
Excess dose during pregnancy can cause birth defects.
Contraindications Mineral oil, cholestyramine, alcohol, and antilipemic
drugs decrease the absorption of vitamin A. It is excreted
through the kidneys and feces.*PB=Protein Binding UK = unknown t^1 ⁄ 2 =^1 ⁄ 2 life
Vitamin A
Dose for treatment Mild deficiency: 50–125 μ g/dL
of deficiency Moderate to severe: 2.5–7.5 mg/d; 2500–7500 μ g
Maintenance Male and female: 40–80 μ g; 200–400 IU
Pregnancy category A
Deficiency conditions Rickets, deficit of phosphorus and calcium in blood
Side effects None significant
Adverse reactions Excess of 40,000 international units (IU) results in
hypervitaminosis D and may cause hypercalcemia
(an elevated serum calcium level). Early symptoms of
toxicity are anorexia, nausea, and vomiting.
Contraindications Hypercalcemia, hypervitaminosis D, or renal osteodys-
trophy with hyperphosphatemia. Use with caution
in patients with arteriosclerosis, hyperphosphatemia,
hypersensitivity to vitamin D, and renal or cardiac
impairment.Vitamin D