Regulation of Circulating 1α,25-Dihydroxyvitamin D in β-Thalassemia

To the Editor: The letter by Bell and colleagues (November 28 issue)* demonstrating that black children in the United States maintain very tight concentrations of 1α,25-dihydroxyvitamin D despite alterations in concentrations of 25-hydroxyvitamin D prompts us to write about our observations in patients with β-thalassemia major and iron overload. In a study of 15 patients with this condition, we found a marked seasonal variation in serum concentrations of 25-hydroxyvitamin D. However, there were no changes in the concentrations of calcium, 1α,25-dihydroxyvitamin D, or parathyroid hormone (Table 1). Patients with β-thalassemia in the United Kingdom have marginal vitamin D nutrition, probably., No extract is available for articles shorter than 400 words.