Non-inferiority of Lower Dose Calcium Supplementation During Pregnancy
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ClinicalTrials.gov Identifier: NCT03350516 |
Recruitment Status :
Active, not recruiting
First Posted : November 22, 2017
Last Update Posted : March 16, 2022
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The World Health Organization currently recommends that pregnant women in populations with low calcium intake receive daily calcium supplementation (1500 - 2000 mg) divided into three doses which are preferably taken at mealtimes, in addition to daily iron folic-acid supplements. Despite proven efficacy and the WHO recommendation, calcium supplementation in pregnancy is not standard of care in the vast majority of low-income and middle-income countries. Two important barriers to implementation are the cost of the supplements and complexity of the suggested calcium dosing schedule. A lower dose of calcium (500 mg) administered as a single dose has been shown to be beneficial in several trials, and if found to be as effective as the 1500 mg supplementation regimen, it may help overcome these barriers and increase individual and health system adoption.
The Investigators will conduct two parallel, individually randomized, double blind non-inferiority trials in India and Tanzania. Participating pregnant woman will be randomized to either 1500 mg or 500 mg calcium supplementation. The India and Tanzania trials are independently powered for the primary outcomes of i) preeclampsia and ii) preterm birth. The India and Tanzania sites will each enroll 11,000 participants.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Pregnancy Related | Dietary Supplement: Daily 500 mg elemental calcium as calcium carbonate Dietary Supplement: Daily1500 mg elemental calcium as calcium carbonate | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 22000 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Prevention |
Official Title: | Demonstrating Non-inferiority of Lower Dose Calcium Supplementation During Pregnancy for Reducing Preeclampsia and Neonatal Outcomes |
Actual Study Start Date : | November 30, 2018 |
Estimated Primary Completion Date : | December 1, 2022 |
Estimated Study Completion Date : | December 1, 2022 |

Arm | Intervention/treatment |
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Experimental: Daily 500 mg Calcium |
Dietary Supplement: Daily 500 mg elemental calcium as calcium carbonate
Pregnant women in this arm will be provided and counselled to take three tablets, one containing 500 mg elemental calcium as calcium carbonate and 2 placebo supplements daily (total of 500 mg daily). The supplements in India will also contain 83.3 IU each of vitamin D3, for a total of 250 IU daily. No vitamin D3 will be given in Tanzania. |
Active Comparator: Daily1500 mg Calcium (Standard dose) |
Dietary Supplement: Daily1500 mg elemental calcium as calcium carbonate
Pregnant women in this arm will be provided and counselled to take three tablets each containing 500 mg elemental calcium as calcium carbonate daily (total of 1500 mg daily) as currently recommended by the World Health Organization. The supplements in India will also contain 83.3 IU each of vitamin D3, for a total of 250 IU daily. No vitamin D3 will be given in Tanzania. |
- Proportion of pregnant women with incident preeclampsia [ Time Frame: Gestational week 20 to Delivery ]
- Proportion of preterm birth [ Time Frame: Birth ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Nulliparous
- Attending first ANC visit at study clinics
- Pregnant women <20 weeks
- ≥ 18 years old
- Intending to stay in study area until 6 weeks post delivery
- Provides informed consent
Exclusion Criteria:
- History or signs and/or symptoms of nephrolithiasis
- Prior diagnosis of parathyroid disorder or thyroidectomy
- Diseases that require digoxin, phenytoin, or tetracycline therapy

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03350516
India | |
St. John's Research Institute | |
Bangalore, India | |
Tanzania | |
Africa Academy for Public Health | |
Dar Es Salaam, Tanzania | |
Ifakara Health Institute | |
Dar Es Salaam, Tanzania |
Principal Investigator: | Wafaie W Fawzi, MBBS, DrPH | Harvard School of Public Health (HSPH) |
Responsible Party: | Wafaie Fawzi, Richard Saltonstall Professor of Population Sciences, Professor of Nutrition, Epidemiology, and Global Health, Chair of the Department of Global Health and Population, Harvard School of Public Health (HSPH) |
ClinicalTrials.gov Identifier: | NCT03350516 |
Other Study ID Numbers: |
OPP1172660 |
First Posted: | November 22, 2017 Key Record Dates |
Last Update Posted: | March 16, 2022 |
Last Verified: | March 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Undecided |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Calcium, Dietary Calcium Carbonate Calcium Calcium-Regulating Hormones and Agents Physiological Effects of Drugs |
Bone Density Conservation Agents Antacids Molecular Mechanisms of Pharmacological Action Gastrointestinal Agents |