The Interaction Between Calcium and Vitamin D Intake (PTH Modified)

NYU Langone Hospitals

Status: Completed

Conditions: Osteoporosis

Treatments: Dietary Supplement: Calcium and vitamin D supplementation

Study type: Interventional

Funder types: Other

Identifiers

NCT00762775

08016

33497

Details and patient eligibility

About

We will study the relative importance of high calcium intake and vitamin D supplementation for calcium homeostasis, as determined by serum parathyroid hormone (PTH) and biochemical bone markers. We also intend to examine the interaction of vitamin D and calcium intake on calcium homeostasis. We hypothesize that optimal calcium supplementation and optimal vitamin D supplementation will lead to lower serum levels of PTH and markers of bone resorption compared with the placebo. We also theorize that when taken together, optimal calcium supplementation and optimal vitamin D intake will result in lower serum levels of PTH and bone markers compared with calcium or vitamin D taken alone.

Enrollment: 78 patients

Sex: Female

Ages: 45 to 85 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy women aged 45 and above who have been menopausal at least 1 year (absence of menstrual period for a period of 12 months or more)

Exclusion criteria

• Any chronic medical illness including uncontrolled diabetes mellitus, recent history of myocardial infarction, or heart failure, malignancy, uncontrolled hypertension, obesity (BMI>35 kg/m2), history of anemia, leukemia, or other hematologic abnormalities, lupus, rheumatoid arthritis, or other rheumatologic disease, or kidney disease of any kind as determined by history and physical examination.
• Subjects with osteoporosis of the hip (total hip T-score equal or less than -2.5) or taking medications for osteoporosis such as bisphosphonates will be excluded.
• Pregnancy.
• Use of medication that influences bone metabolism (i.e. anticonvulsant medications, chronic use of steroids and high dose diuretics).
• Significant deviation from normal in medical history, physical examination, or laboratory tests as evaluated by the primary investigator.
• Patients with a history of hypercalciuria, hypercalcemia, nephrolithiasis, and active sarcoidosis will also be excluded.
• Participation in another investigational trial in the past 30 days prior to the screening evaluation.
• Unexplained weight loss of >15% during the previous year or history of anorexia nervosa.
• Medications that interfere with vitamin D metabolism.
• Patients with a habitual dietary calcium intake that exceeds 800 mg/day.
• Smokers greater than 1 pack per day will be excluded.
• Patients reporting alcohol intake greater than 2 drinks daily.
• Serum 25-hydroxyvitamin D level > 75 nmol/L.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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78 participants in 4 patient groups, including a placebo group

1

Experimental group

Description:

Calcium supplementation and placebo

Treatment:

Dietary Supplement: Calcium and vitamin D supplementation

2

Experimental group

Description:

Vitamin D supplementation and placebo

Treatment:

Dietary Supplement: Calcium and vitamin D supplementation

3

Experimental group

Description:

Calcium and Vitamin D supplementation

Treatment:

Dietary Supplement: Calcium and vitamin D supplementation

4

Placebo Comparator group

Description:

Placebos only

Treatment:

Dietary Supplement: Calcium and vitamin D supplementation