Vitamin C status in 137 outpatients with Crohn's disease. Effect of diet counseling.

Vitamin C intake, and serum and leukocyte ascorbate levels were assessed serially over 6 months in 137 outpatients with Crohn's disease. Vitamin C intake was low in 18% of males and 37% of females. Serum ascorbate levels were suboptimal in 11% of males and 18% of females. Leukocyte ascorbate levels were low in 26% of males and 49% of females. Serum ascorbate levels were more frequently below the reference range in patients who smoked, but neither the serum nor the leukocyte ascorbate levels were affected by Crohn's disease activity, the use of an oral contraceptive agent, or by taking prednisone or sulfasalazine. Monthly diet counseling sessions significantly increased vitamin C intake, led to more patients consuming a normal ascorbate intake, and to a normalization of serum ascorbate values. We did not establish the importance of these ascorbate abnormalities on the clinical course of Crohn's disease. We conclude that low serum or leukocyte ascorbate levels are relatively common in patients with active or inactive Crohn's disease; these abnormalities are due in part to the reduced intake of dietary ascorbate; and the ascorbate status in patients with Crohn's disease may be normalized by improving the dietary intake of vitamin C.