the transcobalamin II protein and is then transferred to tissues. Vitamin B 12 is
stored in the liver for up to three years during which time it is slowly excreted
in urine. Vitamin B 12 deficiency is common in patients who are strict vegetari-
ans and in patients who have malaborption syndromes (cancer, celiac disease),
gastrectomy, Crohn’s disease, and liver and kidney diseases.Vitamins and the Nursing Process
The nurse must assess the patient for signs and symptoms of vitamin deficiency
before beginning vitamin therapy because vitamin therapy could result in a toxic
effect if the patient does not have a vitamin deficiency.
In addition, the patient must be assessed for debilitating diseases and GI dis-
orders that may disrupt the absorption, metabolism, and excretion of vitamins
used to treat vitamin deficiency.
For some patients, vitamin deficiency is caused by inadequate nutrient intake.
Therefore, it is critical that the patient’s diet be assessed to determine if it is the(^148) CHAPTER 9 Vitamins and Minerals
Dose 100 mg/dL 14 day
Pernicious anemia: 40–100 μ g/day or 1000
μ g/wk x 3 wk
Maintenance Male and female: 3 μ g/day
Pregnancy: 4 μ g/day
Pregnancy category A (C if use doses >RDA)
Deficiency conditions Pernicious anemia, hemolytic anemia, hyperthyroidism,
bowel and pancreatic malignancies, gastrectomy, GI
lesions, neurologic damage, malabsorption syndrome,
metabolic disorders, renal disease
Side effects Occasional: diarrhea, itching
Adverse reactions Rare allergic reaction; may produce peripheral vascular
thrombosis, pulmonary edema, hypokalemia, CHF
Contraindications History of allergy to cobalimin; folate deficient anemia,
hereditary optic nerve atrophy
Vitamin B 12