201. Vitamin-D status and mineral metabolism in two ethnic populations with sarcoidosis.
- Author
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Capolongo G, Xu LH, Accardo M, Sanduzzi A, Stanziola AA, Colao A, Agostini C, Zacchia M, Capasso G, Adams-Huet B, Moe OW, Maalouf NM, Sakhaee K, and Hsia CC
- Subjects
- Calcium urine, Case-Control Studies, Demography, Female, Glucocorticoids therapeutic use, Humans, Italy, Male, Middle Aged, Nephrolithiasis blood, Nephrolithiasis complications, Nephrolithiasis physiopathology, Sarcoidosis drug therapy, Sarcoidosis physiopathology, Sarcoidosis urine, United States, Vitamin D blood, Ethnicity, Minerals metabolism, Sarcoidosis blood, Vitamin D analogs & derivatives
- Abstract
Vitamin-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.)
- Published
- 2016
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