Patients with thalassemia have low circulating levels of many nutrients, but the contribution of dietary intake has not been assessed.
Assess dietary intake in a large contemporary sample of patients with thalassemia.
Prospective, longitudinal cohort study using a validated food frequency questionnaire
221 patients (19.7±11.3 yrs, 106 female) categorized into three age groups: young children (3–7.9 y), older children/adolescents (8–18.9 yr), and adult (≥ 19 yr). 78.8% β-thalassemia; 90% chronically transfused.
10 hematology outpatient clinics in the United States and Canada.
Main outcome measures
Comparison of intake with U.S. Dietary Reference Intakes, and correlation with serum 25-OH vitamin D and total body iron stores.
Statistical Analyses Performed
Intake was defined as inadequate if less than the estimated average requirement (EAR). Chi-square, Fisher’s exact and Student’s t-test were utilized to compare intake between age categories and logistic regression analysis to test the relationship between intake and outcomes, controlling for age, gender and race.
Over 30% of patients consumed inadequate levels of vitamin A, D, E, K, folate, calcium, and magnesium. The only nutrients for which >90% of patients consumed adequate amounts were riboflavin, vitamin B12 and selenium. Dietary inadequacy increased with increasing age group (p<0.01) for vitamins A, C, E, B6, folate, thiamin, calcium, magnesium and zinc. Over half the sample took additional supplements of calcium and vitamin D, although circulating levels of 25-OH vitamin D remained insufficient in 61% of patients. Dietary iron intake was not related to total body iron stores.
Patients with thalassemia have reduced intake of many key nutrients. These preliminary findings of dietary inadequacy is concerning and supports the need for nutritional monitoring to determine which patients are at greatest risk for nutritional deficiency. Future research should focus on the effect of dietary quality and nutritional status on health outcomes in thalassemia.