Vitamin D Status in Males in Jerusalem Area and Its Correlation to Parathyroid Hormone (PTH) Level and Bone Mineral Density

July 18, 2014 updated by: Metzger Muriel, Clalit Health Services
Because of its high sun exposure, Israel was traditionally supposed to be protected from vitamin D deficiency, and the country food products hardly contain vitamin D supplements. However the Jerusalem ultra-Orthodox population, which constitutes a significant fraction of the city population, is at risk of developing vitamin D deficiency due to low sun exposure, as consequence of its dressing code covering most of the body and very limited time of outside activities. The investigators aim is to check whether vitamin D deficiency is found more frequently in the ultra-Orthodox male population in comparison to a non-ultra-Orthodox male population, and to study its eventual consequences. Correlation between vitamin D levels and PTH levels will be examined, according to age and to creatinine levels. Bone mineral density (BMD) will be evaluated in 2 selected subgroups of subjects (with lowest and highest vitamin D levels), and re-evaluated after 6 months of vitamin D supplementation in vitamin D-deficient subjects. An increase in BMD within 6 months would suggest osteomalacia as the main cause of low BMD in these subjects.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

Subjects:

The study will include 200 males aged 18-70, living in the Jerusalem area. Enrollment will be distributed among 8 clinics of the Clalit Health Services: 4 clinics located in predominantly ultra-Orthodox areas (group A) and 4 clinics located in mixed areas (Group B).

Each group of clinics will enroll 100 subjects as sub-defined:

Age 18-24: 30 patients (Groups A1 and B1) Age 25-39: 30 patients (Groups A2 and B2) Age 40-54: 20 patients (Groups A3 and B3) Age 55-70: 20 patients (Groups A4 and B4)

Study protocol:

Enrollment will be performed by the physicians participating in the study and the nurses working in the corresponding clinics, after advertisement of the study in the clinics.

Visit 1:

  1. The subjects will receive information about the study aims and protocol and will sign an informed consent form.
  2. Blood pressure, height and weight will be measured and BMI calculated.
  3. The subjects will fill a questionnaire concerning their personal habits: dressing code, degree of sun exposure, physical activity, smoking, alcohol consumption, muscular pains and general fatigue.
  4. The physician (co-investigator) signing the informed consent form will rule out subjects presenting pre-defined exclusion criteria.
  5. Blood samples will be drawn for: calcium, phosphorus, PTH, 25 OH Vitamin D, 1,25 OH Vitamin D, magnesium, creatinine, alkaline phosphatase, albumin.
  6. A urine sample will be collected for magnesium and calcium/creatinine ratio.

The subjects will receive the lab results by mail, with a recommendation to consult their family physician in order to receive treatment in case of vitamin D deficiency. (Vitamin D levels <20 ng/ml)

The subjects in the 18-39 age groups (Groups A1, A2, B1 and B2) will be classified according to their vitamin D levels. The 20 subjects presenting the highest vitamin D levels or with vitamin D level>30 ng/ml will constitute the "high D" group and the 40 subjects with the lowest vitamin D levels will constitute the "low D" group. (We expect the vitamin D levels to be above 30 ng/ml in the "high D" group and below 10 ng/ml in the "low D" groups, according to the results of our pilot study).

Subjects with vitamin D level>30 ng/ml or <10 ng/ml can be enrolled to the 60 patients of the "high D" and "low D " groups and will proceed to visits 2 and 3.

Visit 2:

60 subjects (20 from the "high D" group and 40 from the "low D" group) will undergo a bone mineral density examination in the Osteoporosis Center of Mount-Scopus Hadassah Hospital. All subjects with low vitamin D levels will receive a 6-month vitamin D supplementation of 2000 units per day for the first 12 weeks and of 1000 units per day for the next 12 weeks.

Visit 3:

The 60 subjects who underwent visit 2 will undergo visit 3 six months later.

  1. The subjects will fill a questionnaire similar to the first one and detail their degree of compliance with vitamin D supplementation
  2. Blood samples will be drawn for plasma levels of: calcium, phosphorus, magnesium, PTH, 25 OH vitamin D, 1,25 (OH)2 vitamin D, creatinine, alkaline phosphatase, albumin
  3. A urine sample will be collected for magnesium and calcium/creatinine ratio.
  4. A repeat bone mineral density examination will be performed in the Osteoporosis Center Mount-Scopus Hadassah Hospital

The subjects will receive their test results by mail with a recommendation to consult their family physician in case of persistent abnormal results.

Study Type

Interventional

Enrollment (Actual)

210

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Jerusalem., Israel
        • Endocrinology Clinic, Clalit Health Services

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Male subjects aged 18-70
  • If age below 40 must not be under any chronic medication

Exclusion Criteria:

  • Medication: anti-convulsivants, non-topical steroids (past or present), anti-rejection medications
  • Malabsorptive diseases (Crohn's disease, cystic fibrosis,Whipple' disease, s/p bariatric surgery)
  • Morbid obesity (BMI above 35)
  • Rheumatoid arthritis
  • Liver failure
  • Nephrotic syndrome
  • Chronic kidney disease
  • Genetic disorder
  • Malignancy
  • Primary hyperparathyroidism
  • Granulomatous disease
  • Hyperthyroidism
  • Nephrolithiasis (present or past)
  • S/P skin grafts surgery
  • Mental disorder or cognitive disorder

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: group A low D
ultra-Orthodox clinics patients aged 18-39 with lowest vitamin D levels
oral supplementation of 25 OH vitamin D at dose of 2000 units/d for 3 months then 1000 units/d for 3 months
No Intervention: group A high D
ultra-Orthodox clinics patients aged 18-39 with highest vitamin D levels
Active Comparator: group B low D
mixed population clinics patients aged 18-39 with lowest vitamin D levels
oral supplementation of 25 OH vitamin D at dose of 2000 units/d for 3 months then 1000 units/d for 3 months
No Intervention: group B high D
mixed population clinics patients aged 18-39 with highest vitamin D levels

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
plasma vitamin D level
Time Frame: 6 months
6 months

Secondary Outcome Measures

Outcome Measure
Time Frame
bone mineral density before vitamin D supplementation
Time Frame: 8 months
8 months
plasma PTH level
Time Frame: 6 months
6 months
bone mineral density after vitamin D supplementation in vitamin D deficient subjects
Time Frame: 13 months
13 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Muriel Metzger, MD, Clalit Health Services, Jerusalem, Israel
  • Principal Investigator: Anat Tsur, MD, Clalit Health Services, Jerusalem, Israel

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2010

Primary Completion (Actual)

July 1, 2014

Study Completion (Actual)

July 1, 2014

Study Registration Dates

First Submitted

December 1, 2009

First Submitted That Met QC Criteria

December 2, 2009

First Posted (Estimate)

December 3, 2009

Study Record Updates

Last Update Posted (Estimate)

July 21, 2014

Last Update Submitted That Met QC Criteria

July 18, 2014

Last Verified

July 1, 2014

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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