Vitamin B-12 & Bone Health Study for Postmenopausal Women
Who is conducting this study?
This study is led by Lindsay Allen, PhD, and colleagues at the USDA, ARS, Western Human Nutrition Research Center (WHNRC). The funding for this study comes from USDA, ARS, WHNRC. This study has been reviewed and approved by the UC Davis Committee for the Protection of Human Subjects.
What is the purpose of the study?
This study is being conducted to investigate if vitamin B-12 is beneficial in reducing bone loss in postmenopausal women. This study will allow us to develop better understanding of bone health.
Who can participate?
Women who are apparently healthy (not taking any prescription medications, non-smoking), between 50 and 65 years, postmenopausal (no menses during past 15 months), and with a healthy body weight for height (BMI between 20 and 30) can participate. We will measure your vitamin B-12 status (serum B-12) and measure your bone density to find out if you meet the study criteria of moderately low B-12 status and moderately low bone density. We especially need volunteers who are willing and able to visit the research site (WHNRC) at UC Davis 10 times and who can commit to the study schedule for nine months.
Who is NOT eligible to participate?
•• Women who are not healthy (on certain medications, smoking or using tobacco products),
•• Women who are younger than 50 and older than 65,
•• Women who used hormone replacement therapy (HRT) within the last 12 months
What do I need to do to participate?
During VISIT 1, you will complete a health-screening visit at WHNRC, 430 West Health Sciences Drive on the UC Davis campus, including questionnaires, height, weight, vital signs and a fasting blood draw. Fasting means no food or drink except water for 12 hours before your appointment. Your blood will be analyzed for serum vitamin B-12 concentration and to check for anemia. Within a week, you will be phoned or written to let you know if you are qualified for the study or not, based on the vitamin B-12 and anemia tests. You will be paid $30 for this screening visit.
If you are eligible to participate, we will schedule VISIT 2 at the WHNRC between 8:00 a.m. and 4:00 p.m. If your initial serum vitamin B-12 was less than 100 pg/mL, you will be treated by a registered nurse or medical assistant with 1000 ?g intramuscular injection of vitamin B-12 (standard medical practice) and you will be invited to remain in the study if you choose. Then you will participate in a bone scan (total body, spine and hip) using a DXA. Your bone density scan results with interpretation will be completed within 1 week.
A. If the result shows that you have osteoporosis (T score less than -2.5), you will be sent a copy of the report and advised to consult your physician for further diagnosis and treatment.
B. If the result shows that you have osteopenia, of a T score between -1.6 and -2.5, you will be sent a copy of the report and given information on how to avoid osteoporosis and you will be provided three months' supply of calcium and vitamin D supplements.
C. If the result shows that you have osteopenia, of a T score between -1 and -1.5, you will qualify for the study.
D. If the result shows that you have normal bone density, a T score greater than -1, you will qualify for the study.
If you qualify for the study, and wish to participate, you will be provided with a 24-hour urine collection container and instructions. This may be mailed to you, or you can pick it up. You will be asked to collect a 24-hour urine sample at home prior to Visit 3.
At VISIT 3, you will bring your 24-hour urine sample to the WHNRC at a morning appointment after fasting for 12 hours. You will consume a very low dose (10 nCi) of radioactive calcium (as calcium carbonate, 41CaCO3) with a glass of water. This procedure will help us measure how much calcium you are excreting in your urine. This is a standard procedure that has been used in many research studies to assess bone calcium loss. The amount of radiation exposure would be comparable to that of a cross-country airplane trip. You are free to consume your usual diet and engage in your usual activities. You will be provided dietary supplements of calcium (1,000 mg per day) and vitamin D (400 IU per day) to take daily, along with a pill container. You will be provided a calendar to record that you have taken the dietary supplements on each day. You will be asked to complete a dietary questionnaire. You will also be provided more supplies, and asked to collect and bring 24-hour urine collections to the WHNRC three months and four months after the calcium-41 dose, as well as your calendar (that will be VISIT 4, 5).
One month later, at VISIT 6, after we receive your 24-hour urine collection and we take a fasting blood sample, you will be randomly assigned to one of the two treatments: either vitamin B-12 or placebo group. If you are assigned to the B-12 group, you will receive a 1000 ?g dose of injectable vitamin B-12 administered intramuscularly (i.m.) by a registered nurse or medical assistant. In addition to the injection, we will provide you with vitamin B-12 supplements (500 ug/day) to consume daily during the subsequent three months, along with the calcium and Vitamin D. If you are assigned to the placebo group, you will be given a saline injection similar in appearance to the vitamin B-12 injection and placebo capsules identical in appearance to the vitamin B-12 supplements. Please keep in mind that if you are in the placebo group, you will still be given the vitamin B-12 injection, three months' of vitamin B-12 supplements at the end of the study.
For the next three weeks, you will visit the WHNRC with your 24-hour urine collection and in the fasting state for the blood draw on a weekly basis (VISIT 7, 8, and 9). Three months after visit 9 will be the last visit (VISIT 10) where you will visit the WHNRC with your 24-hour urine collection, in fasting state for the blood draw and for your last DEXA bone scan.
What are the benefits to you from this study?
You will receive:
•• DXA bone scan
•• Evaluation of your vitamin B-12 status
•• Vitamin B-12 injection, vitamin B-12 supplements, vitamin D and calcium supplements free of charge
•• Nutrition Information
•• Compensation: $30 for the initial screening visit, $20 for each blood draw, and $10 for each urine sample for the total of $210.
What should I do if I have more questions?
Call 530-752-5177 and press #6 to leave a message or use our Recruitment Form to email us.
