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Endocrine Care: Elisabetta Romagnoli, Maria Lucia Mascia, Cristiana Cipriani, Valeria Fassino, Franco Mazzei, Emilio D'Erasmo, Vincenzo Carnevale, Alfredo Scillitani, and Salvatore Minisola Short and Long-Term Variations in Serum Calciotropic Hormones after a Single Very Large Dose of Ergocalciferol (Vitamin D2) or Cholecalciferol (Vitamin D3) in the Elderly J Clin Endocrinol Metab 2008; 93: 3015-3020 [Abstract] [Full text] [PDF]

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RENAL FUNCTION AND PTH RESPONSE

Elisabetta Romagnoli, Vincenzo Carnevale, and Salvatore Minisola   (5 August 2008)

PTH response to vitamin D supplementation

Sanjeev Patel, Mehdi Mirzazadeh, Steve Hyer, Jeffrey Barron   (22 June 2008)

RENAL FUNCTION AND PTH RESPONSE 5 August 2008
Elisabetta Romagnoli, MD Department of Clinical Sciences, University of Rome, Vincenzo Carnevale, and Salvatore Minisola Send letter to journal: Re: RENAL FUNCTION AND PTH RESPONSE romagnoli.elisabetta{at}fastwebnet.it Elisabetta Romagnoli, et al.	We are writing in response to Dr. Patel’s E-letter regarding our paper on the biochemical effects of a very large dose of vitamin D supplementation in the elderly (1). We agree that, besides the highly significant correlation between serum 25(OH)D and PTH values, the possible influence on PTH secretion of other factors, such as serum magnesium (2) or renal function (3), can not be ignored. Accordingly, baseline GFR could also influence PTH response to vitamin D supplementation. However, this conclusion can not be drawn from our data. In fact, we investigated a small sample of elderly women with a relatively narrow range of estimated creatinine clearance values (60-75 mL/min). Moreover, neither the modified MDRD formula (4), nor, consequently, the MDRD-based K/DOQI staging have been specifically validated in older subjects. Therefore, we believe that the interesting hypothesis suggested by Dr. Patel et al. could be investigated only through a study specifically designed to address this theory. References 1. Romagnoli E, Mascia ML, Cipriani C, Fassino V, Mazzei F, D’Erasmo E, Carnevale V, Scillitani A, Minisola S. 2008 Short and long term variations in serum calciotropic hormones after a single very large dose of ergocalciferol (Vitamin D2) or cholecalciferol (Vitamin D3) in the elderly. J Clin Endocrinol Metab doi:10.1210/jc.2008-0350 2. Sahota O, Mundey MK, San P, Godber IM, Hosking DJ 2006 Vitamin D insufficiency and the blunted PTH response in established osteoporosis: the role of magnesium deficiency. Osteoporos Int 14:1013-1021 3. Patel S, Hyer S, Barron J. 2007 Glomerular filtration rate is a major determinant of the relationship between 25-hydroxyvitamin D and parathyroid hormone. Calcif Tissue Int 80:221-226 4. Levey AS, Bosch JP, Breyer Lewis J, Greene T, Rogers N, Roth D, for the Modification of Diet in Renal Disease Study Group. 1999 A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Ann Intern Med 130:461-470
PTH response to vitamin D supplementation 22 June 2008
Sanjeev Patel, Consultant Physician St Helier University Hospital, Mehdi Mirzazadeh, Steve Hyer, Jeffrey Barron Send letter to journal: Re: PTH response to vitamin D supplementation sanjeev.patel{at}epsom-sthelier.nhs.uk Sanjeev Patel, et al.	We read the paper by Romagnoli et al. (1) with great interest. Their study and findings are very important as their data will add to work to define an optimal regimen for correction of vitamin D deficiency. We have previously shown in a cross-sectional study that glomerular filtration rate (GFR) is an important determinant of serum PTH levels in patients with vitamin D deficiency (2). Patients with vitamin D deficiency and low GFR had much higher serum PTH levels compared to those patients with vitamin D deficiency and relatively normal GFR. Therefore our question is whether Romagnoli et al. (1) observed any variation in the PTH response to vitamin D supplementation according to the baseline GFR of these patients? It may be difficult to give a confident answer, as presumably GFR was low in all individuals, given that the patients were approximately 80 years of age and the numbers relatively small numbers. Nonetheless trying to define predictors of PTH response to vitamin D in addition to dose and level of vitamin D is clinically important. References 1. Romagnoli E, Mascia ML, Cipriani C, Fassino V, Mazzei F, D'Erasmo E, Carnevale V, Scillitani A, Minisola S 2008 hort and Long Term Variations in Serum Calciotrophic Hormones after a Single Very Large Dose of Ergocalciferol (Vitamin D2) or Cholecalciferol (Vitamin D3) in the Elderly. J Clin Endocrinol Metab doi:10.1210/jc.2008-0350 2. Patel S, Hyer S, Barron J 2007 Glomerular filtration rate is a major determinant of the PTH response to vitamin D Calcified Tissue Int 80:221-226