• Giovanna Capolongo, Li Hao Richie Xu, Mariasofia Accardo, Alessandro Sanduzzi, Anna Agnese Stanziola, Annamaria Colao, Carlo Agostini, Miriam Zacchia, Giovambattista Capasso, Beverley Adams-Huet, Orson W Moe, Naim M Maalouf, Khashayar Sakhaee, and Connie C W Hsia.
• Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA Charles & Jane Pak Center for Mineral Metabolism & Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA Department of Cardio-thoracic & Respiratory Sciences, Division of Nephrology, Second University of Naples, Naples, Italy.
• J. Investig. Med. 2016 Jun 1; 64 (5): 1025-34.

AbstractVitamin-D insufficiency and sarcoidosis are more common and severe in African Americans (AA) than Caucasians. In sarcoidosis, substrate-dependent extrarenal 1,25-dihydroxyvitamin-D (1,25-(OH)2D) production is thought to contribute to hypercalciuria and hypercalcemia, and vitamin-D repletion is often avoided. However, the anti-inflammatory properties of vitamin-D may also be beneficial. We prospectively examined serum vitamin-D levels, calcium balance, and the effects of vitamin-D repletion in 86 AA and Caucasian patients with biopsy-proven active sarcoidosis from the USA (US) and Italy (IT) in university-affiliated outpatient clinics. Clinical features, pulmonary function, and calciotropic hormones were measured. 16 patients with vitamin-D deficiency and normal serum ionized calcium (Ca(2+)) were treated with oral ergocalciferol (50,000 IU/week) for 12 weeks. Baseline mineral parameters were similar in US (93% AA) and IT (95% Caucasian) patients irrespective of glucocorticoid treatment. Pulmonary dysfunction was less pronounced in IT patients. Nephrolithiasis (in 11% US, 17% IT patients) was associated with higher urinary calcium excretion. Vitamin-D deficiency was not more prevalent in patients compared to the respective general populations. As serum 25-hydroxyvitamin-D (25-OHD) rose postrepletion, serum 1,25-(OH)2D, γ-globulins, and the previously elevated angiotensin converting enzyme (ACE) levels declined. Asymptomatic reversible increases in Ca(2+) or urinary calcium/creatinine (Ca/Cr) developed in three patients during repletion. In conclusion, Caucasian and AA patients show similar calcium and vitamin D profiles. The higher prevalence of hypercalciuria and nephrolithiasis in sarcoidosis is unrelated to endogenous vitamin-D levels. Vitamin-D repletion in sarcoidosis is generally safe, although calcium balance should be monitored. A hypothesis that 25-OHD repletion suppresses granulomatous immune activity is provided.Copyright © 2016 American Federation for Medical Research.

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