Skip to content

Efficacy and Safety of Low-dose Calcium Supplementation in Pregnancy

Efficacy and Safety of Low-dose CAlcium Supplementation in pREgnancy: a Pilot Study (CARE Pilot)

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07784218
Acronym
CARE Pilot
Enrollment
117
Registered
2026-08-25
Start date
2025-09-10
Completion date
2026-07-08
Last updated
2026-08-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pregnancy

Keywords

Pregnancy, Calcium Supplementation

Brief summary

This study is a prospective, randomized, double-blind controlled pilot trial designed to comprehensively evaluate the efficacy and safety of a targeted low-dose (300 mg/day) versus a standard high-dose (600 mg/day) calcium supplementation during mid-to-late pregnancy. The main research content is divided into the following four core dimensions: 1. Evaluation of Maternal Skeletal and Systemic Calcium Efficacy: The core efficacy evaluation focuses on the preservation of maternal bone mineral density throughout mid-to-late pregnancy. This is assessed by the change in the BMD Z-score (ΔZ-score) from baseline to delivery using quantitative ultrasound (QUS). Concurrently, by comparing pre- and post-intervention maternal serum total calcium concentrations, the study verifies whether the low-dose regimen is sufficient to maintain normal systemic calcium homeostasis and support fetal development. 2. Safety Assessment of Renal Filtration and Metabolic Burden: To investigate the potential metabolic toxicity of high-dose calcium, the study explicitly evaluates the maternal renal calcium excretion burden. By measuring the change in the fasting urinary calcium-to-creatinine ratio (ΔU-Ca/Cr) before and after the intervention, the research aims to determine whether the targeted low-dose regimen effectively prevents iatrogenic absorptive hypercalciuria induced by excessive calcium overload. 3. Evaluation of Clinical Gastrointestinal Tolerability: Given that gastrointestinal adverse events are the primary deterrent to prenatal supplement adherence, this study utilizes the internationally recognized Rome IV criteria to rigorously track and compare the time-to-onset and cumulative incidence of moderate-to-severe constipation between the two groups, thereby quantifying the difference in intestinal tolerability between the dosages. 4. Exploration of Adverse Pregnancy Outcomes and General Safety: As an exploratory clinical endpoint, the study records and compares the incidence rates of preeclampsia and preterm birth between the two intervention arms to ensure the low-dose regimen safely maintains prophylactic benefits against adverse obstetric outcomes. Furthermore, a comprehensive panel of maternal general laboratory parameters (e.g., hepatic and renal function, lipid profiles, and hematology) is monitored throughout to guarantee overall systemic safety.

Interventions

DRUGCalcium

Participants in the treatment group received calcium 300 mg/day and the control group received calcium 600 mg/day.

Sponsors

First People's Hospital of Hangzhou
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
FEMALE
Age
14 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

* Pregnant women aged 18 to 45 years * Gestational age between 22 and 28 weeks * Body mass index (BMI) between 19.0\~28.0 kg/m2 * Willingness to comply with the study protocol and provision of informed consent

Exclusion criteria

* Known hypersensitivity or allergy to any active components or excipients of the study medications * Multifetal gestation * History of chronic constipation or functional defecation disorders prior to or during early pregnancy * Current clinical hypercalcemia, hyperuricemia, familial hyperlipidemia, or intestinal malabsorption disorders * History of prolonged extreme low-calcium diets or severe diagnosed nutritional deficiencies * History of illicit substance abuse, chronic alcoholism, heavy smoking, or excessive caffeine intake

Design outcomes

Primary

MeasureTime frameDescription
Moderate-to severe constipationThrough study completion, an average of 20 weeksTime-to-onset and cumulative incidence of moderate-to-severe constipation (Rome IV criteria)
ΔZ-scoreBaseline and before deliveryChange in Bone Mineral Density (BMD) Z-score from baseline to delivery measured by Quantitative Ultrasound (QUS)

Secondary

MeasureTime frameDescription
Serum calciumBaseline and before delivery
ΔU-Ca/CrBaseline and before deliveryChange in urinary calcium-to-creatinine ratio

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 26, 2026