Blog
About

3
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Vitamin D Insufficiency and Deficiency in Chronic Kidney Disease

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Background: Kidney disease has been identified as a risk factor for vitamin D deficiency in hospitalized patients, and low levels of 25-hydroxyvitamin D have been suggested to be a risk factor for hyperparathyroidism in patients with chronic kidney disease (CKD). However, little is known about the magnitude of vitamin D deficiency in patients with CKD living in the United States. Methods: In this regard, we examined the levels of 25(OH)D in 43 patients with CKD and serum creatinine between 1 and 5 mg/dl (calculated glomerular filtration rate 111–11 ml/min per 1.73 m<sup>2</sup>) as well as in 103 patients undergoing hemodialysis. Results: In the predialysis patients, we found that 37 of the 43 patients (86%) had suboptimal levels of vitamin D (<30 ng/ml). Regression analysis indicated that there was a negative correlation between 25(OH)D and intact parathyroid hormone (PTH). Alkaline phosphatase showed a similar but less sensitive relationship. Serum albumin levels correlated with 25(OH)D levels. In contrast to findings reported in normal individuals, the levels of calcitriol correlated with those of 25(OH)D in the patients with CKD. In the group undergoing maintenance hemodialyis, we found that 97% of the patients had vitamin D levels in the suboptimal range, and there was no correlation of 25(OH)D levels with either PTH or serum albumin values. These data indicate that vitamin D insufficiency and deficiency are highly prevalent in patients with CKD and may play a role in the development of hyperparathyroidism. The functional significance of low levels of 25(OH)D in patients with stage 5 CKD remains to be determined.

          Related collections

          Most cited references 21

          • Record: found
          • Abstract: found
          • Article: not found

          Vitamin D3 and calcium to prevent hip fractures in the elderly women.

          Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known. We studied the effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women (mean [+/- SD] age, 84 +/- 6 years). Each day for 18 months, 1634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 micrograms (800 IU) of vitamin D3, and 1636 women received a double placebo. We measured serial serum parathyroid hormone and 25-hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women. Among the women who completed the 18-month study, the number of hip fractures was 43 percent lower (P = 0.043) and the total number of nonvertebral fractures was 32 percent lower (P = 0.015) among the women treated with vitamin D3 and calcium than among those who received placebo. The results of analyses according to active treatment and according to intention to treat were similar. In the vitamin D3-calcium group, the mean serum parathyroid hormone concentration had decreased by 44 percent from the base-line value at 18 months (P < 0.001) and the serum 25(OH)D concentration had increased by 162 percent over the base-line value (P < 0.001). The bone density of the proximal femur increased 2.7 percent in the vitamin D3-calcium group and decreased 4.6 percent in the placebo group (P < 0.001). Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Hypovitaminosis D in medical inpatients.

            Vitamin D deficiency is a major risk factor for bone loss and fracture. Although hypovitaminosis D has been detected frequently in elderly and housebound people, the prevalence of vitamin D deficiency among patients hospitalized on a general medical service is unknown. We assessed vitamin D intake, ultraviolet-light exposure, and risk factors for hypovitaminosis D and measured serum 25-hydroxyvitamin D, parathyroid hormone, and ionized calcium in 290 consecutive patients on a general medical ward. A total of 164 patients (57 percent) were considered vitamin D-deficient (serum concentration of 25-hydroxyvitamin D, < or = 15 ng per milliliter), of whom 65 (22 percent) were considered severely vitamin D-deficient (serum concentration of 25-hydroxyvitamin D, <8 ng per milliliter). Serum 25-hydroxyvitamin D concentrations were related inversely to parathyroid hormone concentrations. Lower vitamin D intake, less exposure to ultraviolet light, anticonvulsant-drug therapy, renal dialysis, nephrotic syndrome, hypertension, diabetes mellitus, winter season, higher serum concentrations of parathyroid hormone and alkaline phosphatase, and lower serum concentrations of ionized calcium and albumin were significant univariate predictors of hypovitaminosis D. Sixty-nine percent of the patients who consumed less than the recommended daily allowance of vitamin D and 43 percent of the patients with vitamin D intakes above the recommended daily allowance were vitamin D-deficient. Inadequate vitamin D intake, winter season, and housebound status were independent predictors of hypovitaminosis D in a multivariate model. In a subgroup of 77 patients less than 65 years of age without known risk factors for hypovitaminosis D, the prevalence of vitamin D deficiency was 42 percent. Hypovitaminosis D is common in general medical inpatients, including those with vitamin D intakes exceeding the recommended daily allowance and those without apparent risk factors for vitamin D deficiency.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              An endocytic pathway essential for renal uptake and activation of the steroid 25-(OH) vitamin D3.

              Steroid hormones may enter cells by diffusion through the plasma membrane. However, we demonstrate here that some steroid hormones are taken up by receptor-mediated endocytosis of steroid-carrier complexes. We show that 25-(OH) vitamin D3 in complex with its plasma carrier, the vitamin D-binding protein, is filtered through the glomerulus and reabsorbed in the proximal tubules by the endocytic receptor megalin. Endocytosis is required to preserve 25-(OH) vitamin D3 and to deliver to the cells the precursor for generation of 1,25-(OH)2 vitamin D3, a regulator of the calcium metabolism. Megalin-/- mice are unable to retrieve the steroid from the glomerular filtrate and develop vitamin D deficiency and bone disease.
                Bookmark

                Author and article information

                Journal
                AJN
                Am J Nephrol
                10.1159/issn.0250-8095
                American Journal of Nephrology
                S. Karger AG
                0250-8095
                1421-9670
                2004
                October 2004
                01 December 2004
                : 24
                : 5
                : 503-510
                Affiliations
                Division of Nephrology, Saint Louis University, St. Louis, Mo., USA
                Article
                81023 Am J Nephrol 2004;24:503–510
                10.1159/000081023
                15452403
                © 2004 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                Page count
                Figures: 6, Tables: 2, References: 39, Pages: 8
                Product
                Self URI (application/pdf): https://www.karger.com/Article/Pdf/81023
                Categories
                Original Report: Patient-Oriented, Translational Research

                Cardiovascular Medicine, Nephrology

                Vitamin D, End-stage renal disease, Chronic kidney disease

                Comments

                Comment on this article