Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Alerts
  • Advertising/recruitment
  • Subscribe
  • Contact
  • Current Issue
  • Past Issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Author's Takes
  • Reviews
    • View all reviews ...
    • 100th Anniversary of Insulin's Discovery (Jan 2021)
    • Hypoxia-inducible factors in disease pathophysiology and therapeutics (Oct 2020)
    • Latency in Infectious Disease (Jul 2020)
    • Immunotherapy in Hematological Cancers (Apr 2020)
    • Big Data's Future in Medicine (Feb 2020)
    • Mechanisms Underlying the Metabolic Syndrome (Oct 2019)
    • Reparative Immunology (Jul 2019)
    • View all review series ...
  • Viewpoint
  • Collections
    • Recently published
    • In-Press Preview
    • Commentaries
    • Concise Communication
    • Editorials
    • Viewpoint
    • Top read articles
  • Clinical Medicine
  • JCI This Month
    • Current issue
    • Past issues

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Author's Takes
  • Recently published
  • In-Press Preview
  • Commentaries
  • Concise Communication
  • Editorials
  • Viewpoint
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Alerts
  • Advertising/recruitment
  • Subscribe
  • Contact
Top
  • View PDF
  • Download citation information
  • Send a letter
  • Share this article
  • Terms of use
  • Standard abbreviations
  • Need Help? E-mail the JCI
  • Top
  • Abstract
  • Version history
  • Article usage
  • Citations to this article

Advertisement

Research Article Free access | 10.1172/JCI111995

Evidence for alteration of the vitamin D-endocrine system in blacks.

N H Bell, A Greene, S Epstein, M J Oexmann, S Shaw, and J Shary

Find articles by Bell, N. in: JCI | PubMed | Google Scholar

Find articles by Greene, A. in: JCI | PubMed | Google Scholar

Find articles by Epstein, S. in: JCI | PubMed | Google Scholar

Find articles by Oexmann, M. in: JCI | PubMed | Google Scholar

Find articles by Shaw, S. in: JCI | PubMed | Google Scholar

Find articles by Shary, J. in: JCI | PubMed | Google Scholar

Published August 1, 1985 - More info

Published in Volume 76, Issue 2 on August 1, 1985
J Clin Invest. 1985;76(2):470–473. https://doi.org/10.1172/JCI111995.
© 1985 The American Society for Clinical Investigation
Published August 1, 1985 - Version history
View PDF
Abstract

As compared with values in white subjects, bone mass is known to be increased and urinary calcium to be diminished in black individuals. To evaluate the possibility that these changes are associated with alterations in the vitamin D-endocrine system, an investigation was performed in 12 black subjects, 7 men and 5 women, and 14 white subjects, 8 men and 6 women, ranging in age from 20 to 35 yr. All of them were hospitalized on a metabolic ward and were given a constant daily diet containing 400 mg of calcium, 900 mg of phosphorus, and 110 meq of sodium. Whereas mean serum calcium, ionized calcium, and phosphate were the same in the two groups, mean serum immunoreactive parathyroid hormone (350 +/- 34 vs. 225 +/- 26 pg/ml, P less than 0.01) and mean serum 1,25-dihydroxyvitamin D (1,25(OH)2D) (41 +/- 3 vs. 29 +/- 2 pg/ml, P less than 0.01) were significantly higher, and mean serum 25-hydroxy-vitamin D (25-OHD) was significantly lower in the blacks than in the whites (6 +/- 1 vs. 20 +/- 2 ng/ml, P less than 0.001). Mean urinary sodium and 24-h creatinine clearance were the same in the two groups, whereas mean urinary calcium was significantly lower (101 +/- 14 vs. 166 +/- 13 mg/d, P less than 0.01) and mean urinary cyclic AMP was significantly higher (3.11 +/- 0.47 vs. 1.84 +/- 0.25 nM/dl glomerular filtrate, P less than 0.01) in the blacks. Further, the blacks excreted an intravenous calcium load, 15 mg/kg body weight, as efficiently as the whites (49 +/- 3 vs. 53 +/- 3%, NS). Mean serum Gla protein was lower in blacks than in whites (14 +/- 2 vs. 24 +/- 3 ng/ml, P less than 0.02), and increased significantly in both groups in response to 1,25(OH)2D3, 4 micrograms/d for 4 d. There was a blunted response of urinary calcium to 1,25(OH)2D3 in the blacks, and mean serum calcium did not change. The results indicate that alteration of the vitamin D-endocrine system with enhanced renal tubular reabsorption of calcium and increased circulating 1,25(OH)2D as a result of secondary hyperparathyroidism may contribute to the increased bone mass in blacks. Their low serum 25-OHD is attributed to diminished synthesis of vitamin D in the skin because of increased pigment.

Browse pages

Click on an image below to see the page. View PDF of the complete article

icon of scanned page 470
page 470
icon of scanned page 471
page 471
icon of scanned page 472
page 472
icon of scanned page 473
page 473
Version history
  • Version 1 (August 1, 1985): No description

Article tools

  • View PDF
  • Download citation information
  • Send a letter
  • Share this article
  • Terms of use
  • Standard abbreviations
  • Need Help? E-mail the JCI

Metrics

  • Article usage
  • Citations to this article

Go to

  • Top
  • Abstract
  • Version history
Advertisement
Advertisement
Follow JCI:
Copyright © 2021 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts