Hypertension, Vitamin D Deficiency
Conditions
Brief summary
Adequate levels of vitamin D are essential for bone health at all ages but low levels of vitamin D may also negatively impact other aspects of health such as blood pressure. The investigators have previously shown that adults with African ancestry living near the equator have much higher levels of vitamin D and higher levels of blood pressure compared to adults with African ancestry living in the Chicago area. Multiple clinical trials have examined vitamin D supplementation for reducing blood pressure levels but very few studies have focused on adults with African ancestry and low vitamin D levels. In addition, most previous clinical trials have not addressed calcium intake. While vitamin D may modulate blood pressure via its actions on activation of the renin angiotensin aldosterone system, it is also possible that vitamin D mediates blood pressure via its effects on gastrointestinal calcium absorption. This pilot study is a one arm study, which will assess the safety and feasibility of supplementing 15 young adults with African ancestry and low vitamin D levels with 5,000 IU of Cholecalciferol (vitamin D3) combined with 1000 mg of elemental calcium daily for 3 months. Participants will be recruited from the Maywood Illinois and surrounding areas with flyers and brochures. The investigators will also contact previous participants of the Modeling the Epidemiologic Study/Vitamin D Ancillary Study by phone and letters. At baseline, all participants will have blood pressure measured and will provide a fasting serum specimen and a 24-hour urine collection. Calcium, parathyroid hormone level vitamin D will be measured in serum specimens and 24-hour urine calcium excretion will be measured. Repeat visits will be completed at 6 and 12 weeks of follow-up to again measure resting blood pressure and serum calcium and vitamin D levels. The overall goal is to collect pilot data to help design a larger trial of vitamin D and calcium supplementation for lowering blood pressure in young adults with African ancestry.
Detailed description
This pilot study will recruit 15 black U.S. adults ages 25-45 years of age with 25(OH)D levels \< 20 ng/ml and no use of anti-hypertensive medications and a resting seated systolic blood pressure ≥ 120 mmHg and will measure baseline levels of total 25(OH)D, 25(OH)D2, 25(OH)D3, free vitamin 25(OH)D, active vitamin D \[1,25(OH)D\], parathyroid hormone level, serum calcium, and 24-hour calcium excretion. Participants will then take the supplements vitamin D3 5000 IU and elemental calcium 1000 mg daily for three months. Investigators will measure changes in blood pressure, total 25(OH)D, 25(OH)D2 and 25(OH)D3, 1,25(OH)D and free 25(OH)D, parathyroid hormone levels, serum calcium and 24-hour urine calcium excretion over the three month period. The overall goal is to collect pilot data to determine the feasibility of a larger trial to determine whether vitamin D combined with calcium lowers blood pressure in young black adults with low 25(OH)D levels. This will be a single arm non-blinded feasibility study of 15 participants. The study population will consist of 15 adults ages 25-45 years with self-reported African American race/ethnicity. All participants will provide written informed consent. Intervention: This study has only one arm and all participants will receive Cholecalciferol (vitamin D3) 5,000 IU daily for 3 months and 1000 mg of calcium citrate daily for 3 months. There will be no placebo and no blinding of the agent. Participants will receive a 3 month supply of drugs which will be administered by the Loyola pharmacy. Serum vitamin D and calcium levels will be measured at study initiation and at 6 and 12 weeks (study end). Participants will stop taking stop both vitamin D and calcium administration with serum calcium levels are greater than or equal to 10.6 meq/L and/or a 25(OH)D levels are greater than or equal to 80 ng/dl at the 6 week visit. Safety Monitoring: The investigators will query any hospitalizations or emergency room visits over the past month and reasons for those visits at the baseline, 6 and 12 week follow-up visits. Serum calcium and vitamin D levels will be measured at 6 and 12 weeks and anyone with serum calcium levels ≥ 10.6 meq/L and/or a 25(OH)D level ≥ 80 ng/ml will stop treatment. All adverse events will be reported to the Loyola University Chicago Health Sciences Institutional Review Board. A data safety and monitoring board will review all data collected after completion of the 6 week visit to ensure safety of the study. Stopping plans: Any participant who develops a serum calcium levels ≥ 10.6 meq/L and/or a 25(OH)D level ≥ 80 ng/ml will stop treatment but they will continue to be monitored in the study through week 12 when serum calcium and 25(OH)D levels will be measured at the end of the study. The study will continue until participants have been followed for 12 weeks. Analysis Plan: This feasibility study will examine multiple aspects of the pilot data including the total number of persons enrolled vs. number of total persons identified as eligible. Pill counts will be done at the 6 and 12 week visit to assess compliance with vitamin D and calcium supplementation. The percentage of participants taking 80% or more of the vitamin D3 supplement and the calcium supplement will be determined. The number of participants reporting symptoms and all adverse events will be quantified. Repeated measures analysis of variance models will be used to assess change in the outcome measures including systolic and diastolic blood pressure, vitamin D measures, parathyroid hormone levels and 24-hour urine calcium excretion values.
Interventions
DRUGCholecalciferol
5000 IU cholecalciferol with 1000 mg calcium citrate daily
Sponsors
Loyola University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
This pilot study is a one arm study which will assess the safety and feasibility of supplementing 15 young adults with African ancestry and low vitamin D levels with 5,000 IU of Cholecalciferol (vitamin D3) combined with 1000 mg of elemental calcium daily for 3 months
Eligibility
Sex/Gender
ALL
Age
25 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
1. Age 25-45 years 2. Self-reported race/ethnicity African American 3. BMI ≥ 18 kg/m2 4. Total 25(OH)D levels \< 20 ng/ml (50 nmol/L) 5. No use of vitamin D supplements within past 30 days of the screening visit 6. Able to provide written informed consent 7. Willing to take a vitamin D supplement daily for 3 months 8. Willing to return for follow-up visits to measure blood pressure and provide a blood sample to measure vitamin D and serum calcium 9. No current use of blood pressure lowering medications 10. Systolic blood pressure ≥ 100 mmHg and diastolic blood pressure ≥ 60 mmHg
Exclusion criteria
1. Medical history of chronic disease that affect gastrointestinal absorption of vitamin D: Crohn's disease, cystic fibrosis, and celiac disease 2. Use of medications which may affect total 25(OH)D levels: antiepileptic drugs, steroids, bile acid sequestrants, lipase inhibitors, orlistat 3. Current use of vitamin D supplements or use in past month and unwillingness to discontinue for at least 1 month prior to study enrollment 4. History of kidney stones or hypercalciuria 5. Fasting serum calcium ≥ 10.2 mg/dl 6. Average systolic blood pressure ≥ 140 mmHg 7. Average diastolic blood pressure ≥ 90 mmHg 8. Presence of type 1 diabetes mellitus, active malignancy, active thyroid disease or sarcoidosis 9. Pregnant or planning a pregnancy 10. Estimated glomerular filtration rate (based on serum creatinine level) is \< 60 ml/min/1.73 m2 based on the Modification of Diet in Renal Disease formula
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Mean Blood Pressure From Baseline to 12 Weeks | Difference in BP from baseline and 12 weeks after initiation of intervention | Seated blood pressure is measured at baseline and at 6 and 12 week follow-up visits in the clinic using an appropriate sized cuff after a rest period using an automated device (Omron). Blood pressure will be measured three times in one minute intervals at each time point and the average of these three recordings will be recorded as the mean blood pressure at each time point. Arm circumference will be measured to ensure the correct cuff size is used for all blood pressure measurements including home monitoring of blood pressure. Due to small number of participants, the change in mean blood pressure was analyzed as difference in mean blood pressure (2 x average diastolic blood pressure + average systolic blood pressure)/3 between baseline and at 12 weeks. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Total 25-hydroxyvitamin D From Baseline to 12 Weeks | Change in total 25-hydroxyvitamin D level from baseline to 12 weeks after initiation of intervention | Total 25-hydroxyvitamin D will be measured with the use of liquid chromatography-tandem mass spectrometry |
| Change in Free 25-hydroxyvitamin D Levels From Baseline to 12 Weeks | Baseline and at 12 weeks after initiation of intervention | Free 25(OH)D levels-will be measured using kits from Future Diagnostics (Wijchen, The Netherlands). |
| Change in Intact Parathyroid Hormone Levels From Baseline to 12 Weeks | Change in PTH levels from baseline and at 12 weeks after initiation of intervention | Intact parathyroid hormone levels will be measured with the use of the Elecsys Parathyroid Hormone Immunoassay |
| Change in 1,25-dihydroxyvitamin D From Baseline to 12 Weeks | Change in 1,25 dihydroxyvitamin D levels from baseline and at 12 weeks after initiation of intervention | 1,25 -dihydroxyvitamin D will be measured with the use of liquid chromatography-tandem mass spectrometry |
| Change in 24-hour Urine Calcium Excretion From Baseline to 12 Weeks | Change in 24 hour urine calcium excretion from baseline and at 12 weeks after initiation of intervention | A 24-hour urine will be collected and calcium will be measured by Quest diagnostics |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Vitamin D Participants will all receive supplementation with cholecalciferol 5000 IU and calcium citrate 1000 mg daily for 3 months
Cholecalciferol: 5000 IU cholecalciferol with 1000 mg calcium citrate daily | 5 |
| Total | 5 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Lost to Follow-up | 2 |
Baseline characteristics
| Characteristic | Vitamin D |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 5 Participants |
| Age, Continuous | 38.4 years |
| Mean arterial blood pressure | 90 mmHg |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 0 Participants |
| Region of Enrollment United States | 5 participants |
| Sex: Female, Male Female | 5 Participants |
| Sex: Female, Male Male | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 5 |
| other Total, other adverse events | 0 / 5 |
| serious Total, serious adverse events | 0 / 5 |
Outcome results
Primary
Change in Mean Blood Pressure From Baseline to 12 Weeks
Seated blood pressure is measured at baseline and at 6 and 12 week follow-up visits in the clinic using an appropriate sized cuff after a rest period using an automated device (Omron). Blood pressure will be measured three times in one minute intervals at each time point and the average of these three recordings will be recorded as the mean blood pressure at each time point. Arm circumference will be measured to ensure the correct cuff size is used for all blood pressure measurements including home monitoring of blood pressure. Due to small number of participants, the change in mean blood pressure was analyzed as difference in mean blood pressure (2 x average diastolic blood pressure + average systolic blood pressure)/3 between baseline and at 12 weeks.
Time frame: Difference in BP from baseline and 12 weeks after initiation of intervention
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Vitamin D Arm | Change in Mean Blood Pressure From Baseline to 12 Weeks | 4.3 mmHg |
Secondary
Change in 1,25-dihydroxyvitamin D From Baseline to 12 Weeks
1,25 -dihydroxyvitamin D will be measured with the use of liquid chromatography-tandem mass spectrometry
Time frame: Change in 1,25 dihydroxyvitamin D levels from baseline and at 12 weeks after initiation of intervention
Population: 1,25 vitamin D was never measured due to lack of funding
Secondary
Change in 24-hour Urine Calcium Excretion From Baseline to 12 Weeks
A 24-hour urine will be collected and calcium will be measured by Quest diagnostics
Time frame: Change in 24 hour urine calcium excretion from baseline and at 12 weeks after initiation of intervention
Population: 3 participants who completed the trial
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Vitamin D Arm | Change in 24-hour Urine Calcium Excretion From Baseline to 12 Weeks | 336.2 mg/day |
Secondary
Change in Free 25-hydroxyvitamin D Levels From Baseline to 12 Weeks
Free 25(OH)D levels-will be measured using kits from Future Diagnostics (Wijchen, The Netherlands).
Time frame: Baseline and at 12 weeks after initiation of intervention
Population: We did not measure free vitamin D and only measured total vitamin D because we ran out of funding
Secondary
Change in Intact Parathyroid Hormone Levels From Baseline to 12 Weeks
Intact parathyroid hormone levels will be measured with the use of the Elecsys Parathyroid Hormone Immunoassay
Time frame: Change in PTH levels from baseline and at 12 weeks after initiation of intervention
Population: 3 participants who completed the trial
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Vitamin D Arm | Change in Intact Parathyroid Hormone Levels From Baseline to 12 Weeks | 27.5 pg/ml |
Secondary
Change in Total 25-hydroxyvitamin D From Baseline to 12 Weeks
Total 25-hydroxyvitamin D will be measured with the use of liquid chromatography-tandem mass spectrometry
Time frame: Change in total 25-hydroxyvitamin D level from baseline to 12 weeks after initiation of intervention
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Vitamin D Arm | Change in Total 25-hydroxyvitamin D From Baseline to 12 Weeks | 21.7 ng/ml |