Requirements for sodium, potassium, and chloride vary widely. Most patients require 45–145 mEq/day of each. The actual requirement in individual patients will depend on the patient's cardiovascular, renal, endocrine, and gastrointestinal status as well as measurements of serum concentration.
Patients receiving enteral nutritional support should receive adequate vitamins and minerals according to the recommended daily allowances. Most premixed enteral solutions provide adequate vitamins and minerals as long as adequate calories are administered.
Patients receiving parenteral nutritional support require smaller amounts of minerals: calcium, 10–15 mEq/day; phosphorus, 15–20 mEq per 1000 nonprotein calories; and magnesium, 16–24 mEq/day. Most patients receiving nutritional support do not require supplemental iron because body stores are adequate. Iron nutrition should be monitored closely by following the hemoglobin concentration, mean corpuscular volume, and iron studies.
Patients receiving parenteral nutritional support should be given the trace elements zinc (about 5 mg/day) and copper (about 2 mg/day). Patients with diarrhea will require additional zinc to replace fecal losses. Additional trace elements—especially chromium, manganese, and selenium—are provided to patients receiving long-term parenteral nutrition.
Parenteral vitamins are provided daily. Standardized multivitamin solutions are currently available to provide adequate quantities of vitamins A, B12, C, D, E, thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, folic acid, and biotin. Vitamin K is not given routinely but administered when the prothrombin time becomes abnormal.