Vitamin D for Painful Nocturnal Leg Cramps

Summary

1. Research question: Does vitamin D reduce the frequency and severity of nocturnal leg cramps in older persons who previously took quinine for leg cramps?
2. Experimental Design: This is a randomized, double blind, placebo controlled study of 70 men and women veterans receiving care at the Madison VA Medical Center(VAMC) or at the University of Wisconsin Hospitals and Clinics (UWHC). Individuals age 50 or more who have previously taken quinine for nocturnal leg cramps and meeting baseline criteria are eligible to enroll. Enrollees meeting laboratory criteria, including low-normal vitamin D levels, will undergo a 2-week "diary run-in" period to confirm cramp frequency. Those who report two or more leg cramps in each week will continue in the study and will be randomized to vitamin D or placebo. After a two-week wash-in, subjects will take a vitamin D capsule (50,000 units) once daily for 10 days, followed by a once weekly vitamin D (50,000 units) maintenance dose for 7 weeks. Subjects will record by diary the number and severity of leg cramps from the start of the "diary run-in" until a week after the last dose of study drug. Study investigators will call subjects at scheduled intervals to assess compliance, tolerability, and diary use.
3. Major risks to subjects: No major risks are anticipated. Excessive vitamin D can increase blood calcium levels (hypercalcemia), with symptoms such as thirst, nausea, and weakness. However, symptomatic hypercalcemia has not been reported except for those taking more than 40,000 units daily for several months. This is far above the cumulative dose in our study.
4. Potential benefits: Subjects may not receive any benefit. Vitamin D may alleviate leg cramps for subjects who receive it.
5. Consent Procedure: Flyers describing the study and telephone contact information will be mailed to patients who have received quinine during the period 2002-2007. The PI or Co-PI will return calls to describe the study and answer any questions. For persons meeting preliminary (pre-lab) study criteria, two copies of the consent form will be mailed, with the patient mailing back one signed consent to the PI.

Conditions

• Leg Cramps, Nocturnal

Interventions

DRUG

vitamin d

After a two-week wash-in, subjects will take a vitamin D capsule (50,000 units) once daily for 10 days, followed by a once weekly vitamin D (50,000 units) maintenance dose for 7 weeks.

DRUG

placebo

After a two-week wash-in, subjects will take a placebo capsule once daily for 10 days, followed by a once weekly maintenance dose for 7 weeks.

Sponsors & Collaborators

• Mayday Fund

  collaborator OTHER

• University of Wisconsin, Madison

  lead OTHER

Principal Investigators

• Mary E Elliott, PhD · University of Wisconsin, Madison

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

50 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2007-08-31

Primary Completion

2011-08-31

Completion

2011-08-31

FDA Drug

Yes

Countries

• United States

Study Locations