Mineral and Vitamin Status on High-Fiber Diets: Long-Term Studies of Diabetic Patients

High-fiber diets have a beneficial impact on glucose metabolism of selected persons with diabetes mellitus. A major concern is the long-term effects of fiber intake on mineral and vitamin status. We measured serum concentrations of selected minerals and vitamins and also assessed three fat-soluble vitamins in 15 patients fed high-fiber diets for an average of 21 mo. Average values for serum calcium, phosphorus, alkaline phosphatase, iron-binding capacity, magnesium, and hemoglobin values were normal. Vitamin B₁₂ and folic acid concentrations in serum were also normal. Indirect assessment suggested that these patients had adequate intakes of the fat-soluble vitamins A, D, and K. These preliminary observations suggest that high-fiber diets containing a wide variety of natural foods are well tolerated for up to 51 mo; we failed to detect evidence suggesting mineral or vitamin deficiency in these patients.