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Impact of Food Additives on Phosphorus Metabolism

This study has been completed.
Information provided by (Responsible Party):
Orlando M. Gutierrez, MD, MMSc, University of Alabama at Birmingham Identifier:
First received: July 12, 2011
Last updated: September 28, 2015
Last verified: September 2015
The purpose of the study is to learn more about how phosphorus-based food additives affect phosphorus metabolism in people with normal kidney function.

Condition Intervention
Other: Research diet

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Official Title: Impact of Food Additives on Phosphorus Metabolism

Resource links provided by NLM:

Further study details as provided by University of Alabama at Birmingham:

Primary Outcome Measures:
  • FGF23 [ Time Frame: 2 weeks ]
    Change in FGF23 levels

  • PTH [ Time Frame: 2 weeks ]
    Change in PTH levels over 2 weeks

  • Serum phosphate [ Time Frame: 2 weeks ]
    Change in serum phosphate over two weeks

Secondary Outcome Measures:
  • Insulin sensitivity as measured by HOMA-IR [ Time Frame: 2 weeks ]
    changes in HOMA-IR over two weeks

  • Brachial flow mediated dilatation measured by ultrasound [ Time Frame: 2 weeks ]
    change in flow mediated dilatation over two weeks

Enrollment: 54
Study Start Date: April 2011
Study Completion Date: June 2014
Primary Completion Date: June 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Subjects with healthy kidney function Other: Research diet
Participants will be provided specially prepared meals to eat at home for two weeks. During the first week, participants will eat foods that do not have any phosphorus-based food additives in them (this is called the control diet). During the second week, participants will eat foods that all have phosphorus-based food additives in them (called the intervention diet).

Detailed Description:
Phosphorus is a mineral that is found in foods such as dairy products, nuts, and meat, and is important for strengthening the bones. However, too much phosphorus in the blood may be bad for the health of your heart and blood vessels. The kidneys keep the blood levels of phosphorus normal by getting rid of extra phosphorus in the urine. New research has found that common forms of food additives that are high in phosphorus may increase blood phosphorus levels in individuals with kidney disease. In addition, these food additives may increase blood levels of hormones that control phosphorus such as parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23). Like high blood phosphorus levels, high levels of PTH and FGF23 in the blood may also be bad for the health of your heart and blood vessels. In this study, the investigators would like to examine the effects of food additives on blood levels of phosphorus, PTH and FGF23 in individuals with normal kidney function.

Ages Eligible for Study:   19 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Healthy volunteers, 19 - 45 years of age

Exclusion Criteria:

  • abnormal urinalysis—presence of hematuria, proteinuria, or leukocyturia.
  • pregnancy or breast-feeding
  • Medical conditions impacting phosphate metabolism—primary hyperparathyroidism; gastrointestinal malabsorption disorders such as Crohn's Disease, ulcerative colitis, celiac disease, or liver dysfunction; hyper- or hypothyroidism; irregular menses for female subjects.
  • Body Mass Index (BMI) ≥ 30 g/m2 since obesity is independently associated with impaired phosphorus metabolism.
  • Medications known to affect phosphorus metabolism— current use of phosphorus supplements, high-dose or activated vitamin D compounds, regular antacid or laxative use, anticonvulsants.
  • Hyper- or hypophosphatemia (≥ 4.6 mg/dl or ≤ 2.5 mg/dl respectively), hyper- or hypocalcemia (≥ 10.6 or ≤ 8.5 mg/dl respectively), or severe anemia (hemoglobin < 8 g/dl for women and < 9 g/dl for men).
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Please refer to this study by its identifier: NCT01394146

United States, Alabama
University of Alabama
Birmingham, Alabama, United States, 35294
Sponsors and Collaborators
University of Alabama at Birmingham
Principal Investigator: Orlando M Gutierrez, MD, MMSc University of Alabama at Birmingham
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Orlando M. Gutierrez, MD, MMSc, Assistant Professor, University of Alabama at Birmingham Identifier: NCT01394146     History of Changes
Other Study ID Numbers: F110118001
Study First Received: July 12, 2011
Last Updated: September 28, 2015

Keywords provided by University of Alabama at Birmingham:
phosphorus-based food additives
phosphorus metabolism processed this record on May 24, 2017