Water-soluble vitamins in cancer patients on parenteral nutrition: a prospective study.

Forty-three patients with mild weight loss were studied prospectively to determine whether the parenteral water-soluble vitamin doses in a commercially available preparation (MVI concentrate; USV Laboratories, Tarrytown, NY) maintained serum, red blood cell (RBC), and urinary concentrations of water-soluble vitamins in stressed cancer patients receiving total parenteral nutrition (TPN). Patients were divided into three groups: (1) oral diet, no intravenous vitamins given; (2) TPN plus 5 ml MVI; and (3) TPN plus 10 ml MVI. Vitamins C, B1, B2, B3, B6, and niacin were measured initially and weekly during a 6-week study period. Caloric and nitrogen balances were quantified. Most of the patients in all three groups had normal blood or urine levels of all water-soluble vitamins. No clinical evidence of vitamin deficiency or MVI toxicity was detected. The recommended parenteral dosages of vitamin C (100 mg/day) and B3 (15 mg/day) provided measurably adequate levels in all patients. Levels of vitamins B1, B2, B6, and niacin that were less than the normal range were noted in 4-40% of patients receiving the recommended daily dosages of 3 mg, 3.6 mg, 4 mg, and 40 mg, respectively. These deficiencies appeared to improve in group III patients who received twice the recommended parenteral vitamin dosages, although they did not completely disappear. Niacin deficiency appeared to be the most prevalent, occurring in 40% of patients studied. Since intravenous doses of B1, B2, B6, and niacin are safe and well tolerated, it appears that increased daily amounts of these vitamins should be given to cancer patients on parenteral nutrition.