The Effect of Protein on Calcium Absorption and Gastric Acid Production

Osteoporosis Clinical Trial

Official title:

Dietary Protein's Effect on Gastric pH and Calcium Absorption

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00719160
• Other study ID #: 0910005852
• Secondary ID: 129772
• Status: Completed
• Phase: Phase 4
• Start date: January 2005
• Est. completion date: May 2008

Study information

• Verified date: March 2020
• Source: Yale University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

We have established that dietary protein is an important regulator of intestinal calcium absorption in humans. However, we do not understand the mechanism by which dietary protein is affecting calcium absorption. Therefore, the purpose of this research is to evaluate whether dietary protein-induced changes in gastric acid secretion explain the observed changes in intestinal calcium absorption.

Description:

We have established that dietary protein is an important regulator of intestinal calcium absorption in humans. However, we do not understand the mechanism by which dietary protein is affecting calcium absorption. Therefore, the purpose of this research is to evaluate whether dietary protein-induced changes in gastric acid secretion explain the observed changes in intestinal calcium absorption. We have compelling in vitro data that amino acids can stimulate gastric acid secretion. We have found that this occurs via allosteric activation of the calcium sensing receptor expressed on the gastric acid-secreting parietal cells. At a fixed concentration of extracellular calcium, addition of L but not D isomers of specific amino acids activates the calcium sensing receptor and stimulates parietal cell acid production. We hypothesize that dietary protein induced gastric acid production increases calcium solubility and bioavailability thereby increasing its absorption. We will test this hypothesis in humans by quantifying the impact of dietary protein on intestinal calcium absorption in subjects who cannot make gastric acid. We will measure intestinal calcium absorption in healthy adults as they consume either a high protein diet with concomitant administration of a proton pump inhibiting (PPI) drug or the same high protein diet with a placebo instead of a PPI. The order of the 2 interventions will be randomized, and study will be double-blind and placebo controlled. If our hypothesis is correct, then intestinal calcium absorption will be highest during the high protein diet with placebo, and lowest during the drug intervention.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 12
• Est. completion date: May 2008
• Est. primary completion date: May 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 45 Years

Eligibility

Inclusion Criteria:

• Healthy men and women age 18-45 years

• Caucasian or Asian descent due to increased risk of Osteoporosis

Exclusion Criteria:

• gastrointestinal diseases

• osteoporosis

• diabetes

• hypertension

• liver disease

• thyroid disorders

• kidney disease

• kidney stones

• cancer

• heart disease

• eating disorders

• obesity

• hypogonadism

• amenorrhea

• oligomenorrhea

• abnormal serum FSH or estradiol levels

• birth control medication or other hormone-altering medications

• pregnancy

• Lifestyle factors such as:

• smoking

• excessive exercise (although moderate exercise is allowed)

• prescription medications known to influence vitamin D or calcium metabolism or gastric acid

• excessive body weight change during the past 6 months

• food allergies

• unusual eating habits or medically prescribed diets

Related Conditions & MeSH terms

• Osteoporosis

Intervention

Drug:
• esomeprazole
2 Interventions with esomeprazole 20 mg twice a day for 9 days vs. a placebo for 9 days while on a high protein diet
• Placebo
Placebo 20 mg twice a day for 9 days

Locations

Country	Name	City	State
United States	Yale New Haven Hospital Hospital Research Unit	New Haven	Connecticut

Sponsors (1)

Lead Sponsor	Collaborator
Yale University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Percent Change in Intestinal Calcium Absorption	This is completed by measuring the amount of calcium absorbed by utilizing dual stable calcium isotopes. It was hypothesized that we would see a percent decrease as a result of the proton pump inhibitor. Previous published data indicated a decline in calcium absorption of 6.6 +/- 5.5% when gastric pH is blocked.	Day 5 of a high protein diet
Secondary	Gastric pH	The American Heritage Dictionary defines pH as "a measure of the acidity or alkalinity of a solution, numerically equal to 7 for neutral solutions, increasing with increasing alkalinity and decreasing with increasing acidity. The pH scale commonly in use ranges from 0 to 14." The normal pH range for stomach acid is between 1.5 and 3.5.	Day 5 of a high protein diet